CN116217906A - A kind of glycolide ring-opening polymerization process using novel initiator - Google Patents

Abstract

The invention relates to a glycolide ring-opening polymerization process using a novel initiator, a polymerization system composed of glycolide, a catalyst and an initiator, the initiator contains a hydrophilic and hydrophobic group and contains sulfur , nitrogen and other heteroatoms. In traditional catalysts, while catalyzing polymerization, metal ions will complex with oxygen atoms of ester bonds to catalyze the breakage of polyglycolide (PGA) ester bonds, resulting in a decrease in the molecular weight of PGA and an increase in the color of the product. The heteroatoms contained in the novel initiator of the invention have strong complexing ability to metals, can form relatively stable coordination complexes with catalysts, prevent PGA from breaking, and reduce product chroma. In addition, the addition of the new initiator introduces some flexible segments, lowers the freezing point of PGA, and lowers the polymerization temperature. Compared with the prior art, the present invention has the advantages of high product molecular weight, relatively uniform molecular weight distribution, large polymerization reaction time operation flexibility, wide temperature control window, etc., and is suitable for industrial production.

Description

A kind of glycolide ring-opening polymerization process using novel initiator

technical field

The invention relates to the technical field of polymer material synthesis, in particular to a glycolide ring-opening polymerization process using a novel initiator.

Background technique

Although traditional polymer materials such as PP, PE, PS, etc. have brought a lot of convenience to life, they have caused serious "white pollution" due to imperfect recycling and their own difficulty in degrading in the earth's environment. Therefore, the development of degradable and environmentally friendly polymer materials to replace traditional non-degradable polymer materials has become an important research direction. Polyglycolide (PGA for short) is a completely biodegradable material that is harmless to the environment. It can be hydrolyzed in organisms, and can also be metabolized by microorganisms in a natural environment, and finally decomposed into water and carbon dioxide. It has a wide range of applications in the field of biomedical materials. At present, the synthesis and production process of polyglycolide has become more and more mature, but the metal ion in the traditional catalyst will complex with the oxygen atom of the ester bond to catalyze the breakage of the ester bond of polyglycolide (referred to as PGA) while catalyzing the polymerization, resulting in The obtained product has darker color, smaller PGA molecular weight, insufficient melt strength and tensile strength, slower degradation rate, and is not suitable for the conventional application of plastic products and the promotion of biological materials. In addition, the production and synthesis process of polyglycolide has high energy consumption, low production efficiency and high cost, making it difficult to replace the existing market of traditional plastics. Therefore, systematically researching the polymerization process of polyglycolide, exploring and improving the synthesis process of polyglycolide is of great significance for the industrial promotion and commercialization of polyglycolide in the degradable plastic market in the future.

There are two processes for the preparation of polyglycolide, one is obtained by direct dehydration polycondensation of glycolic acid. The polyglycolide obtained by this process has a low molecular weight, which is difficult to be used for processing molding materials; the other is to heat and decompose the glycolic acid polycondensation polymer to obtain cyclic glycolide, and use glycolide ring-opening polymerization to obtain a molecular weight of tens of thousands to Hundreds of thousands of polyglycolide. Patent CN101616907A reports the preparation of polyglycolide with a weight-average molecular weight Mw greater than 200,000 by glycolide ring-opening polymerization, but a large amount of high-boiling solvents are used in the polymerization process, which increases the energy consumption of the preparation process and solvent recycling the cost of. Patent CN111087580A (Pujing Chemical Industry) obtains polyglycolic acid with a higher weight average molecular weight by adding a dehydrating agent to polyglycolic acid with a weight average molecular weight lower than 20,000. This process increases the molecular weight of polyglycolic acid from 14,000 to 70,000. If it is less than 100,000, the cost of raw materials will increase and the process will be complicated.

Contents of the invention

In view of the shortcomings of the prior art described above, the object of the present invention is to provide a glycolide ring-opening polymerization process using a novel initiator to solve the problems in the prior art.

The present invention is achieved through the following technical solutions:

The present invention provides a kind of glycolide ring-opening polymerization technology on the one hand, described technology comprises the following steps at least:

(1) Carry out prepolymerization reaction with glycolide monomer, catalyst and initiator under certain temperature and pressure, to provide PGA prepolymer; Wherein, described initiator comprises hydrophilic functional group, hydrophobic functional group and at least one of heteroatoms;

(2) polymerizing the PGA prepolymer provided in step (1) under reduced pressure to provide PGA oligomers;

(3) The PGA oligomer provided in step (2) is further polymerized under reduced pressure to obtain a PGA high polymer.

Another aspect of the present invention provides a system for the ring-opening polymerization process of glycolide, which includes a reactor, a first-stage reactor, a second-stage reactor, and a third-stage reactor connected in sequence along the direction of raw material flow.

Another aspect of the present invention provides a polyglycolide, which is prepared by the glycolide ring-opening polymerization process as described in the present invention.

Another aspect of the present invention provides the use of polyglycolide as described in the present invention in the field of degradable plastics.

Compared with prior art, the beneficial effect of the present invention is:

In the glycolide ring-opening polymerization process using a novel initiator of the present invention, the heteroatom contained in the initiator has a strong ability to complex metals and can form a relatively stable coordination complex with the catalyst , to prevent PGA breakage, thereby reducing product chroma. At the same time, the addition of the new initiator introduces part of the flexible segment, which reduces the freezing point of PGA and lowers the polymerization temperature. Therefore, the present invention has great significance for obtaining polyglycolide with high molecular weight and uniform distribution, reducing polymerization temperature, reducing energy consumption and the like. In addition, the process of the present invention has the advantages of high flexibility in polymerization reaction time operation and wide temperature control window, and is suitable for industrial production.

Detailed ways

Hereinafter, an embodiment of a glycolide ring-opening polymerization process using a novel initiator will be specifically disclosed in detail.

A "range" disclosed herein is defined in terms of lower and upper limits, and a given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive and may be combined arbitrarily, ie any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are contemplated. Additionally, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all expected: 1-3, 1-4, 1-5, 2- 3, 2-4 and 2-5. In this application, unless otherwise stated, the numerical range "a-b" represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article, and "0-5" is only an abbreviated representation of the combination of these values. In addition, when expressing that a certain parameter is an integer ≥ 2, it is equivalent to disclosing that the parameter is an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

If there is no special description, all the implementation modes and optional implementation modes of the present application can be combined with each other to form new technical solutions.

If there is no special description, all the technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

Unless otherwise specified, all steps in the present application can be performed sequentially or randomly, preferably sequentially. For example, the process includes steps (1) and (2), which means that the process may include steps (1) and (2) performed in sequence, or may include steps (2) and (1) performed in sequence. For example, mentioning that the process can also include step (3), means that step (3) can be added to the process in any order, for example, the process can include steps (1), (2) and (3) , may also include steps (1), (3) and (2), may also include steps (3), (2) and (1) and so on.

If there is no special description, the "comprising" and "comprising" mentioned in this application mean open or closed. For example, the "comprising" and "comprising" may mean that other components not listed may be included or included, or only listed components may be included or included.

In this application, the term "or" is inclusive unless otherwise stated. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied by either of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; or both A and B are true (or exist).

The applicant of the present invention finds unexpectedly through a large number of experiments, the polymerization system that is made up of glycolide, catalyzer and initiator, monomer glycolide is in catalyst and contains flexible chain segment and special performance feature functional group (hydrophilic group-OH) , -COOR, -CH ₂ OCH ₂ -, etc.) under the action of initiators, ring-opening polymerization can produce high molecular weight PGA with a weight average molecular weight of 100,000 to 380,000. And on this basis, completed the present invention. specific:

The present invention provides a kind of glycolide ring-opening polymerization technology on the one hand, described technology comprises the following steps at least:

(1) Carry out prepolymerization reaction with glycolide monomer, catalyst and initiator under certain temperature and pressure, to provide PGA prepolymer; Wherein, described initiator comprises hydrophilic functional group, hydrophobic functional group and at least one of heteroatoms;

(2) polymerizing the PGA prepolymer provided in step (1) under reduced pressure to provide PGA oligomers;

(3) The PGA oligomer provided in step (2) is further polymerized under reduced pressure to obtain a PGA high polymer.

In the glycolide ring-opening polymerization process provided by the present invention, step (1) is to prepolymerize glycolide monomers, catalysts and initiators at a certain temperature and pressure to provide PGA prepolymers. In a specific embodiment, under normal circumstances, the glycolide monomer, catalyst and initiator can be melted to form a liquid phase first. Specifically, they can be melted under stirring in an autoclave. The temperature in the autoclave is, for example, It can be 100-130°C, and the stirring time can be 30-60 minutes, for example. The melted liquid phase can be sent to the first-stage reactor for pre-polymerization to generate PGA prepolymer.

In the step (1) of the present invention, the initiator usually contains a flexible segment and a functional group with special performance characteristics. Wherein, the hydrophilic functional group in the initiator can be selected from one or more of -OH, -CH ₂ OCH ₂ -, -CHO, -COOH, -COO-, etc., for example. The hydrophobic functional group is selected from one or more of -CH ₃ , -C ₆ H ₅ , -CH ₃ F and the like; the heteroatom is selected from sulfur and/or nitrogen and the like.

In a specific embodiment, the initiator includes a compound having the following general formula:

Wherein, X, R ₁ , R ₂ are each independently selected from O, CRa ₁ R _a2 or SiR _b1 R _b2 ; R _a1 , R _a2 , R _b1 , R _b2 are each independently selected from hydrogen, deuterium, substituted or unsubstituted Any one of C1~C30 straight chain or branched chain alkyl, substituted or unsubstituted C6~C40 aryl, substituted or unsubstituted C3~C40 heteroaryl. In some embodiments, R _a1 , R _a2 , R _b1 , and R _b2 are each independently selected from substituted or unsubstituted C1-C5 straight chain or branched chain alkyl, substituted or unsubstituted C5-C10 straight chain or branched Chain alkyl, substituted or unsubstituted C10~C15 straight chain or branched chain alkyl, substituted or unsubstituted C15~C20 straight chain or branched chain alkyl, substituted or unsubstituted C20~C25 straight chain or branched chain alkyl group, substituted or unsubstituted C25-C30 straight chain or branched chain alkyl group, etc. Preferably, X, R ₁ and R ₂ are each independently selected from O, -CH(CH ₃ )-, -CH ₂ -.

R ₃ is selected from deuterium, halogen, cyano, substituted or unsubstituted C1～C30 linear or branched alkyl, C1～C30 alkoxy, substituted or unsubstituted C6～C40 aryl, substituted or unsubstituted Any one of C3-C40 heteroaryl groups. In some embodiments, R _is selected from substituted or unsubstituted C1～C5 straight chain or branched chain alkyl, substituted or unsubstituted C5～C10 straight chain or branched chain alkyl, substituted or unsubstituted C10～C15 Straight chain or branched chain alkyl, substituted or unsubstituted C15~C20 straight chain or branched chain alkyl, substituted or unsubstituted C20~C25 straight chain or branched chain alkyl, substituted or unsubstituted C25~C30 straight chain Or branched chain alkyl, etc. Preferably, R ₃ is selected from -CHCl ₂ .

n ₁ is an integer selected from 0 to 10; more for example, n ₁ can be selected from 0 to 5, 5 to 10, 0 to 3, 3 to 5, 5 to 8, 8 to 10, etc., or can be selected from 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.

n ₂ is selected from an integer of 0-5; n ₂ may be selected from 0-3, 3-5, etc., or may be selected from 0, 1, 2, 3, 4, 5, etc.

n ₃ is selected from an integer of 0-5; n ₃ may be selected from 0-3, 3-5, etc., or may be selected from 0, 1, 2, 3, 4, 5, etc.

In step (1) of the present invention, the catalyst is selected from metal oxides and metal salts. Preferably, the metal oxide is selected from one or more combinations of antimony trioxide, germanium dioxide, titanium dioxide, zinc oxide and tin oxide. The metal salts are selected from one or more combinations of zinc acetate, stannous octoate, calcium acetate, zinc acetate dihydrate, stannous chloride, and stannous chloride dihydrate.

In step (1) of the present invention, the mass of the catalyst can be 0.01 to 2.0 wt%, 0.01 to 0.05 wt%, 0.05 to 1.0 wt%, 1.0 to 1.5 wt%, or 1.5 to 2.0 wt% of the glycolide monomer mass wt% etc.

In the step (1) of the present invention, the mass of the initiator is 0.01-2.0wt%, 0.01-0.05wt%, 0.05-1.0wt%, 1.0-1.5wt%, or 1.5-1.5wt% of the mass of the glycolide monomer 2.0wt% etc.

In the step (1) of the present invention, the purity of the glycolide monomer is greater than 99%.

In step (1) of the present invention, the pressure of the prepolymerization reaction may be 100-500kPa, 100-200kPa, 200-300kPa, 300-400kPa, or 400-500kPa, etc.

In the step (1) of the present invention, the temperature of the prepolymerization reaction may be 100-220°C, 100-160°C, 160-200°C, or 200-220°C. The temperature of the prepolymerization reaction is preferably 100-160°C.

In the step (1) of the present invention, the time of the prepolymerization reaction may be 1-12h, 1-6h, 6-12h, 1-4h, 4-8h, or 8-12h, etc. The time of the prepolymerization reaction is preferably 1-6h.

In step (1) of the present invention, the weight average molecular weight of the PGA prepolymer may be 1000-10000, 1000-5000, 5000-10000, 1000-3000, 3000-5000, 5000-8000, or 8000-10000.

In step (1) of the present invention, it should be noted that in the prepolymerization process, its main purpose is to remove water or methanol of small molecules, the lower the absolute pressure, the more effective the removal of small molecular substances; residence time and small molecule The removal effect showed a volcano-type curve trend. In a specific embodiment, under the conditions of an absolute pressure of 100kpa and a reaction temperature of 160°C, when the residence time is 1-6h, the weight-average molecular weight of the PGA prepolymer rises from 2500 to 8300, and when the residence time is continued to be extended to 12h, the weight The average molecular weight dropped to 1800.

In the glycolide ring-opening polymerization process provided by the present invention, step (2) is to polymerize the PGA oligomer provided in step (1) under reduced pressure to provide the PGA oligomer.

In step (2) of the present invention, the PGA prepolymer provided needs to be polymerized after further decompression, and the PGA prepolymer provided in step (1) can be decompressed to 10-30kPa, 10-20kPa, 20-30kPa, for example , 10-15kPa, 15-20kPa, 20-25kPa, or 25-30kPa, etc.

In the step (2) of the present invention, in the further polymerization of the PGA prepolymer, the temperature of the polymerization reaction can be 110-220°C, 110-120°C, 120-220°C, 110-160°C, or 160-220°C, etc. . The temperature of the polymerization reaction is preferably 110-200°C.

In the step (2) of the present invention, in the further polymerization of the PGA prepolymer, the time of the polymerization reaction can be 1-10h, 1-5h, 5-10h, etc. The time of the polymerization reaction is preferably 1-5 h.

In step (2) of the present invention, the molecular weight of the PGA oligomer obtained after polymerization is 10000-150000, 10000-50000, 50000-100000, 100000-150000, 10000-30000, 30000-50000, 50000-80000, 80000-100000 , 100000-120000, or 120000-150000 etc.

In step (2) of the present invention, in a specific embodiment, the PGA prepolymer obtained in step (1) is transferred to the second stage reactor, decompressed to 10-30kPa, and polymerized at 110-220°C for 1 -10h, to obtain low molecular weight PGA oligomers with a weight average molecular weight of 10,000 to hundreds of thousands. The molecular weight of PGA oligomer can be 10000-150000, for example, can be 10000-50000, 50000-100000, 100000-150000, 10000-30000, 30000-50000, 50000-80000, 80000-100000, 100000- 120000, or 120000-150000 etc.

In the glycolide ring-opening polymerization process provided by the present invention, in step (3), the PGA oligomer provided in step (2) is further polymerized under reduced pressure to obtain a PGA high polymer.

In the step (3) of the present invention, in the further polymerization reaction of the PGA oligomer, the PGA oligomer provided by the step (2) needs to be further decompressed to 1-2kPa, 1-1.5kPa, or 1.5-2kPa, etc. .

In the step (3) of the present invention, in the further polymerization reaction of the PGA oligomer, the temperature of the polymerization reaction can be, for example, 120-220°C, 120-130°C, 130-200°C, 200-220°C, etc. The temperature of the polymerization reaction is preferably 130-200°C.

In the step (3) of the present invention, in the further polymerization reaction of the PGA oligomer, the time of the polymerization reaction can be, for example, 0.5-10h, 0.5-2h, 2-5h, 5-8h, or 8-10h. The time of the polymerization reaction is preferably 0.5-2h.

In the step (3) of the present invention, in the step (3), the molecular weight of the PGA polymer is 10000-380000, 10000-300000, 300000-380000, 10000-100000, 100000-200000, 200000-300000, etc.

In the step (3) of the present invention, the further polymerization reaction of the PGA oligomer is carried out in the third stage reactor. In a specific embodiment, the oligomer obtained in step (2) is transferred to the third-stage reactor, decompressed to 1-2kPa, and polymerized at 120-220°C for 0.5-10h to obtain a weight-average molecular weight of 10000 -380,000 PGA polymer.

In the glycolide ring-opening polymerization process provided by the present invention, in order to improve efficiency, the prepolymerization reaction temperature should not be lower than the standard boiling point of the lowest boiling point substance in the composition, but in order to prevent the thermal depolymerization of polyglycolide, the three-stage The polymerization temperature should not be too high.

After the reaction, take a small amount of sample for quenching, then use GPC to measure its molecular weight and Ubbelohde viscometer to measure the intrinsic viscosity, and other samples are taken out and processed (granulation, strip, etc.), and then tested by the required properties (crystallization properties , hydrolysis, oxidation resistance, tensile strength, melt index, etc.).

The second aspect of the present invention provides a system for the ring-opening polymerization process of glycolide, which includes a reactor, a first-stage reactor, a second-stage reactor and a third-stage reactor connected in sequence along the direction of raw material flow.

Specifically, in the polymerization system of glycolide ring-opening polymerization, the polymerization system includes a reactor (high-pressure reactor) for storing raw materials and three-stage reactors connected by pipelines in sequence along the flow direction of raw materials, that is, in step (1) The first stage reactor used, the second stage reactor used in step (2) and the third stage reactor used in step (3). The reaction kettle and the polymerization reactor should include no less than one feed and no less than one discharge; the liquid melt is discharged from the bottom of the reactor and fed from the bottom of the reactor. The first-stage reactor, the second-stage reactor, and the third-stage reactor are all commonly used polymerization reactors in the prior art.

The third aspect of the present invention provides polyglycolide, which is prepared by the glycolide ring-opening polymerization process described in the first aspect of the present invention.

The fourth aspect of the present invention provides the use of the polyglycolide described in the third aspect of the present invention in the field of degradable plastics.

Mechanism of the present invention is illustrated as follows:

Polyglycolide is an easily degradable polymer. While increasing the polymerization reaction rate, it is necessary to avoid polymer degradation during the reaction process. On this basis, the molecular weight of the product is increased and the molecular weight distribution is ensured. The initiator is a substance that generates the active center of the free radical polymerization reaction, and is not only an important factor affecting the polymerization reaction rate, but also an important factor affecting the relative molecular weight of the polymer. The present invention has discovered a new type of starting material containing functional groups with special performance characteristics (hydrophilic and hydrophobic groups -OH, -COOH, COO-, -CH ₂ (O)CH ₂ -, etc.) and heteroatoms such as sulfur and nitrogen. The initiator, which can form a stable coordination complex with the catalyst, avoids the breakage of PGA, lowers the freezing point of PGA, lowers the polymerization temperature, and promotes polymerization while effectively increasing the polymerization reaction rate and energy consumption. The rapid increase of molecular weight results in PGA with higher molecular weight and uniform distribution.

Beneficial effects of the present invention:

(1) The polyglycolide prepared by the present invention has good surface color and high weight-average molecular weight, and is very suitable for use as food packaging materials and medical materials.

(2) The initiator used in the present invention reduces the freezing point of PGA, so that the polymerization temperature is reduced, thereby reducing energy consumption.

(3) The glycolide ring-opening polymerization process described in the present invention has large operation flexibility in polymerization reaction time and wide temperature control window, and is suitable for industrialized production.

Below in conjunction with embodiment further illustrate the beneficial effect of the present invention.

In order to make the object, technical solution and beneficial technical effect of the present invention clearer, the present invention will be further described in detail below in conjunction with examples. However, it should be understood that the embodiments of the present invention are only for explaining the present invention rather than limiting the present invention, and the embodiments of the present invention are not limited to the embodiments given in the specification. The specific experimental conditions or operating conditions that are not indicated in the embodiments are made according to conventional conditions, or according to the conditions recommended by the material supplier.

In addition, it should be understood that one or more process steps mentioned in the present invention do not exclude that there may be other process steps before and after the combined steps or other process steps may be inserted between these explicitly mentioned steps, unless otherwise There are instructions; it should also be understood that the combined connection relationship between one or more devices/devices mentioned in the present invention does not exclude that there may be other devices/devices before and after the combined device/devices or those explicitly mentioned Other devices/apparatus can also be interposed between the two devices/apparatus, unless otherwise stated. Moreover, unless otherwise stated, the numbering of each process step is only a convenient tool for identifying each process step, and is not intended to limit the sequence of each process step or limit the scope of the present invention. The change or adjustment of its relative relationship is in In the case of no substantive change in the technical content, it shall also be regarded as the applicable scope of the present invention.

In the following examples, the reagents, materials and instruments used are commercially available unless otherwise specified.

The physical and chemical properties etc. tests mentioned below are as follows:

A. Weight average molecular weight and its distribution

(1) Dissolving the sample in hexafluoroisopropanol solution to prepare a solution with a mass fraction of 0.1% to 0.3%;

(2) Filtrate with a polytetrafluoroethylene filter membrane with a pore size of 0.4 μm;

(3) Take 20 μL and add it into the GPC injector, and use 5 kinds of standard polymethyl methacrylates with different molecular weights for molecular weight calibration.

B. Intrinsic viscosity

Weigh about 0.125g of the sample, dissolve it in 25ml of hexafluoroisopropanol, dissolve it in a constant temperature water bath at 25°C, and use an Ubbelohde viscometer to measure and calculate the intrinsic viscosity (intrinsic viscosity) [η], at 25°C Measured 3 times on average under certain conditions, and the difference in the outflow time of each measurement should not exceed 0.2s.

C. Melt index

The test is carried out according to the method of GB/T 3682.2-2018, the test temperature is 230°C, and the weight of the weight is 2.16kg.

D. Yellowness

The yellowness index was measured by a yellowness index meter.

F. Freezing point

The freezing point was determined by differential scanning calorimetry (DSC).

Weigh an appropriate amount of PGA, place it in a crucible, cover it, place it in a DSC, and use an empty crucible as a reference. Infuse nitrogen gas at a certain flow rate, then raise the temperature to the melting temperature at a heating rate of 10°C/min, keep the temperature constant for 2 minutes, and then cool down at a certain cooling rate until the PGA is completely solidified.

The raw material glycolide monomer needs to be vacuum-dried overnight under the conditions of an absolute pressure of 1-20KPa and a temperature of 40-50°C.

The catalyst is not particularly limited, and may be selected from metal oxides and metal salts; preferably, the metal oxide is selected from one or more of antimony trioxide, germanium dioxide, titanium dioxide, zinc oxide, and tin oxide The combination of species; the metal salts are selected from the combination of one or more of zinc acetate, stannous octoate, calcium acetate, zinc acetate dihydrate, stannous chloride, stannous chloride dihydrate; its consumption is 0.01-2.0 wt% of the mass of raw material monomers.

Example 1

Add 1000g glycolide monomer, 2g stannous octoate and 2.5g compound described in following formula (1) in reactor, be heated to 90 ℃ under normal pressure and reactant is melted completely, then molten matter is transported to absolute In the prepolymerization reactor with a pressure of 200KPa and a temperature of 150°C, stay for 2.5h for prepolymerization; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180°C, and stay for 2h for polymerization , to obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1h to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The weight average molecular weight (Mw) is 350000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.1;

③The intrinsic viscosity is 2.2dL/g;

④The melt index is 5.1g/min;

⑤ The freezing point is 160°C;

⑥ The yellowness index is 26.

chemical formula 1

Example 2

The difference between this example and Example 1 is that the polymerization reaction temperature is different. Specifically, add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound described in the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt In the prepolymerization reactor with an absolute pressure of 200KPa and a temperature of 160°C, stay for 2.5h for prepolymerization; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 200°C, and stay for 2h Carry out polymerization to obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1 hour for final polymerization, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The weight average molecular weight (Mw) is 330000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.2;

③The intrinsic viscosity is 2.01dL/g;

④The melt index is 5.6g/min

⑤ The freezing point is 160°C;

⑥ The yellowness index is 25.

Example 3

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, the temperature is 160 ℃ in the prepolymerization reactor, stay 2.5h for prepolymerization reaction; then transport the obtained prepolymer to the absolute pressure of 20KPa, the temperature is 200 ℃ reactor, stay 2h for polymerization, Obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 215° C. for 1 hour to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 360000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.31;

③The intrinsic viscosity is 2.3dL/g;

④The melt index is 5g/min;

⑤ The freezing point is 158°C;

⑥ The yellowness index is 28.

Example 4

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, 150°C prepolymerization reactor, stay 2.5h for prepolymerization reaction; then transfer the obtained prepolymer to 20KPa absolute pressure, 180°C reactor, stay 2h for polymerization, Obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 215° C. for 1 hour to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 310000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.5;

③The intrinsic viscosity is 1.89dL/g;

④The melt index is 7.2g/min;

⑤ The freezing point is 166°C;

⑥ The yellowness index is 23.

Example 5

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa and a temperature of 130°C in a prepolymerization reactor, stay for 2.5h for prepolymerization; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180°C, stay for 2h for polymerization, Obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200° C. for 1 hour to carry out final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 280000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.63;

③The intrinsic viscosity is 1.73dL/g;

④The melt index is 10g/min;

⑤ The freezing point is 177°C;

⑥ The yellowness index is 20.

Example 6

The difference between this embodiment and embodiment 1 is that the residence time is different. Specifically, add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound described in the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt In the prepolymerization reactor with an absolute pressure of 200KPa and a temperature of 150°C, stay for 6 hours for prepolymerization; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180°C for 5 hours Polymerize to obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 2 hours for final polymerization to finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 365000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.3;

③The intrinsic viscosity is 2.35dL/g;

④The melt index is 4.5g/min;

⑤ The freezing point is 158°C;

⑥ The yellowness index is 28.

Example 7

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, the temperature is 150 ℃ in the prepolymerization reactor, stay 3h for prepolymerization reaction; then transport the obtained prepolymer to the absolute pressure of 20KPa, the temperature is 180 ℃ reactor, stay 3h for polymerization, get PGA oligomer: continue to transport the PGA oligomer to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1.5h to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 350000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.23;

③Intrinsic viscosity is 2.3dL/g;

④The melt index is 5.8g/min;

⑤ The freezing point is 160°C;

⑥ The yellowness index is 27.

Example 8

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, 150°C prepolymerization reactor, stay 2.5h for prepolymerization reaction; then transfer the obtained prepolymer to 20KPa absolute pressure, 180°C reactor, stay 2.5h for polymerization , to obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1.5h to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 352000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.17;

③Intrinsic viscosity is 2.32dL/g;

④The melt index is 6g/min;

⑤ The freezing point is 160°C;

⑥ The yellowness index is 27.

Example 9

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, the temperature is 150 ℃ in the prepolymerization reactor, stay 2h for prepolymerization reaction; then transport the obtained prepolymer to the absolute pressure of 20KPa, the temperature is 180 ℃ reactor, stay 2h for polymerization, get PGA oligomer: continue to transport the PGA oligomer to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1.5h to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 380000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.12;

③Intrinsic viscosity is 2.65dL/g;

④The melt index is 4.6g/min;

⑤ The freezing point is 156°C;

⑥ The yellowness index is 30.

Example 10

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, 150°C prepolymerization reactor, stay for 1.5h for prepolymerization reaction; then transfer the obtained prepolymer to 20KPa absolute pressure, 180°C reactor, stay for 1.5h for polymerization , to obtain PGA oligomers; continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1h to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The average molecular weight (Mw) is 380000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.35;

③The intrinsic viscosity is 3.0dL/g;

④The melt index is 3.5g/min;

⑤ The freezing point is 157°C;

⑥ The yellowness index is 30.

Example 11

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of the compound of the above formula (1) into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to absolute pressure 200KPa, the temperature is 150 ℃ in the prepolymerization reactor, stay 1h for prepolymerization reaction; then transport the obtained prepolymer to the absolute pressure of 20KPa, the temperature is 180 ℃ reactor, stay 1h for polymerization, get PGA oligomer: continue to transport the PGA oligomer to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 0.5h to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The weight average molecular weight (Mw) is 310000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.42;

③The intrinsic viscosity is 1.98dL/g;

④The melt index is 7.5g/min;

⑤ The freezing point is 170°C;

⑥ The yellowness index is 23.

Comparative example 1

Add 1000g of glycolide monomer and 2g of stannous octoate to the reactor, heat to 90°C under normal pressure to completely melt the reactants, then transfer the melted matter to a prepolymerization reaction with an absolute pressure of 200KPa and a temperature of 150°C In the reactor, stay for 2.5h for prepolymerization; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180°C, stay for 2h for polymerization, and obtain PGA oligomers; PGA oligomers Continue transporting to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200° C. for 1 hour to carry out the final polymerization reaction, and finally obtain a PGA polymer.

The assay result to product polyglycolide polymer is as follows:

①The weight average molecular weight (Mw) is 12000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 2.05;

③The intrinsic viscosity is 0.38dL/g;

④The melt index is 50g/min;

⑤ The freezing point is 220°C;

⑥ The yellowness index is 10.

Comparative example 2

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of lauryl alcohol into the reaction kettle, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to an absolute pressure of 200KPa and a temperature of 150 In the prepolymerization reactor at ℃, stay for 2.5h for prepolymerization reaction; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180℃, stay for 2h for polymerization, and obtain PGA oligomers; The PGA oligomer is continuously transported to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200° C. for 1 hour to carry out the final polymerization reaction, and finally a PGA polymer is obtained.

The assay result to product polyglycolide polymer is as follows:

①The weight average molecular weight (Mw) is 130000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.9;

③The intrinsic viscosity is 0.81dL/g;

④The melt index is 45g/min.

⑤ The freezing point is 200°C;

⑥ The yellowness index is 15.

Comparative example 3

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of 1,4 butanediol into the reactor, heat to 90°C under normal pressure to completely melt the reactants, and then transport the melt to an absolute pressure of 200KPa , in a prepolymerization reactor with a temperature of 150°C, stay for 2.5h for prepolymerization; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180°C, stay for 2h for polymerization, and obtain PGA Oligomers: continue to transport the PGA oligomers to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200°C for 1 hour to carry out the final polymerization reaction, and finally obtain a PGA polymer.

①The weight average molecular weight (Mw) is 15000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 1.6;

③The intrinsic viscosity is 0.52dL/g;

④ Melt index is 45g/min;

⑤ The freezing point is 200°C;

⑥ The yellowness index is 15.

Comparative example 4

Add 1000g of glycolide monomer, 2g of stannous octoate and 2.5g of isopropanol into the reaction kettle, heat to 90°C under normal pressure to completely melt the reactant, then transport the melt to an absolute pressure of 200KPa, and the temperature is In the prepolymerization reactor at 150°C, stay for 2.5h for prepolymerization reaction; then transfer the obtained prepolymer to a reactor with an absolute pressure of 20KPa and a temperature of 180°C, stay for 2h for polymerization, and obtain PGA oligomers ; Continue to transport the PGA oligomer to a polymerization reactor with an absolute pressure of 2KPa and a temperature of 200° C. for 1 hour to carry out the final polymerization reaction, and finally obtain a PGA polymer.

①The weight average molecular weight (Mw) is 13000;

②The weight average molecular weight/number average molecular weight (Mw/Mn) ratio is 2.6;

③The intrinsic viscosity is 0.45dL/g;

④The melt index is 56g/min.

⑤ The freezing point is 220°C;

⑥ The yellowness index is 15.

The above description of the embodiments is for those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (10)

1. a glycolide ring-opening polymerization technique, described technique comprises the following steps at least: (1) Carry out prepolymerization reaction with glycolide monomer, catalyst and initiator under certain temperature and pressure, to provide PGA prepolymer; Wherein, described initiator comprises hydrophilic functional group, hydrophobic functional group and at least one of heteroatoms; (2) polymerizing the PGA prepolymer provided in step (1) under reduced pressure to provide PGA oligomers; (3) The PGA oligomer provided in step (2) is further polymerized under reduced pressure to obtain a PGA high polymer. 2. the glycolide ring-opening polymerization technique as claimed in claim 1, is characterized in that, described hydrophilic functional group is selected from -OH, -CH ₂ OCH ₂ -, -CHO, -COOH, -COO- one or more; The hydrophobic functional group is selected from one or more of -CH ₃ , -C ₆ H ₅ , -CHF; The heteroatoms are selected from sulfur and/or nitrogen. 3. glycolide ring-opening polymerization technique as claimed in claim 1, is characterized in that, described starter comprises the compound with following general formula:

Wherein, X, R ₁ , R ₂ are each independently selected from O, CR _a1 R _a2 or SiR _b1 R _b2 ; R _a1 , R _a2 , R _b1 , R _b2 are each independently selected from hydrogen, deuterium, substituted or unsubstituted Any one of C1~C30 straight chain or branched chain alkyl, substituted or unsubstituted C6~C40 aryl, substituted or unsubstituted C3~C40 heteroaryl; R ₃ is selected from deuterium, halogen, cyano, substituted or unsubstituted C1～C30 linear or branched alkyl, C1～C30 alkoxy, substituted or unsubstituted C6～C40 aryl, substituted or unsubstituted Any one of C3～C40 heteroaryl groups; n ₁ is selected from the integers of 0-10; n ₂ is selected from the integers of 0-5; n ₃ is selected from the integers of 0-5. 4. the glycolide ring-opening polymerization technique as claimed in claim 1 is characterized in that, in described step (1), comprises first glycolide monomer, catalyzer and starter melting to form liquid phase, then The liquid phase is prepolymerized in the first stage reactor. 5. glycolide ring-opening polymerization technique as claimed in claim 1, is characterized in that, in described step (1), also comprises any one or more of following characteristics: A1) In step (1), the catalyst is selected from metal oxides and metal salts; preferably, the metal oxide is selected from one of antimony trioxide, germanium dioxide, titanium dioxide, zinc oxide and tin oxide A combination of one or more; the metal salts are selected from one or more combinations of zinc acetate, stannous octoate, calcium acetate, zinc acetate dihydrate, stannous chloride, stannous chloride dihydrate; A2) In step (1), the mass of the catalyst is 0.01 to 2.0 wt% of the mass of the glycolide monomer; A3) In step (1), the mass of the initiator is 0.01 to 2.0 wt% of the mass of the glycolide monomer; A4) In step (1), the purity of the glycolide monomer is greater than 99%; A5) In step (1), the pressure of the prepolymerization reaction is 100-500kPa; A6) In step (1), the temperature of the prepolymerization reaction is 100-220°C; preferably 100-160°C; A7) In step (1), the time of the prepolymerization reaction is 1-12h; preferably 1-6h; A8) In step (1), the weight average molecular weight of the PGA prepolymer is 1000-10000. 6. glycolide ring-opening polymerization technique as claimed in claim 1, is characterized in that, in described step (2), also comprises any one or more of following features: B1) In step (2), the PGA oligomer provided by step (1) is decompressed to 10-30kPa; B2) In step (2), the temperature of the polymerization reaction is 110-220°C; preferably 110-200°C; B3) In step (2), the time of the polymerization reaction is 1-10h; preferably 1-5h; B4) In step (2), the molecular weight of the PGA oligomer is 10000-150000; B5) In step (2), the polymerization reaction of the PGA prepolymer is carried out in the second stage reactor. 7. glycolide ring-opening polymerization technique as claimed in claim 1, is characterized in that, in described step (3), also comprise any one or more of following features: C1) In step (3), the PGA oligomer provided by step (2) is further decompressed to 1-2kPa; C2) In step (3), the temperature of the polymerization reaction is 120-220°C; preferably 130-200°C; C3) In step (3), the time of the polymerization reaction is 0.5-10h; preferably 0.5-2h; C4) In step (3), the further polymerization reaction of the PGA oligomer is carried out in the third stage reactor; C5) In the step (3), the molecular weight of the PGA polymer is 10,000-380,000. 8. A system for the ring-opening polymerization process of glycolide, characterized in that it comprises a reactor, a first-stage reactor, a second-stage reactor and a third-stage reactor connected in sequence along the raw material flow direction. 9. A polyglycolide, prepared by adopting the glycolide ring-opening polymerization process according to any one of claims 1 to 7, and/or the system according to claim 8. 10. Use of the polyglycolide according to any one of claim 9 in the field of degradable plastics.