CN110591047A - A kind of degradable polyether polyurethane and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of polyurethane materials, and discloses degradable polyether polyurethane and a preparation method thereof. Performing controllable ring-opening polymerization on an epoxy monomer by utilizing a carboxylic acid type catalysis/initiation system to synthesize esterified polyether polyol, and then mixing and reacting the esterified polyether polyol with isocyanate to prepare degradable polyether polyurethane; the obtained degradable polyether polyurethane can be degraded at a controllable rate under acidic, alkaline and biological conditions. Compared with the method of introducing ester bonds or acetals into isocyanate or a micromolecular chain extender, the method of the invention has the advantage that no extra micromolecular pre-synthesis step is needed.

Description

A kind of degradable polyether polyurethane and preparation method thereof

technical field

The invention belongs to the field of polyurethane materials, in particular to a degradable polyether polyurethane and a preparation method thereof.

Background technique

The full name of polyurethane is polyurethane (Polyurethanes, PUs), which is a general term for polymer compounds containing repeating urethane (-NHCOO-) groups on the main chain. It is a multi-block copolymer formed by the step-by-step polymerization of organic diisocyanate or polyisocyanate and dihydroxy or polyhydroxy compound. It has the characteristics of easy design of molecular structure and adjustable performance.

Polyurethane molecular chains can generally be divided into soft segments and hard segments. The soft segment is composed of soft segments whose glass transition temperature is lower than room temperature, and the hard segment is composed of rigid segments whose glass transition temperature is higher than room temperature. Soft segments are generally macromolecular polyethers, polyesters, and polycarbonates. The properties of high elasticity, abrasion resistance and weather resistance of polyurethane materials are determined by the flexibility of the soft segment molecular chain. Polyurethane hard segment is composed of isocyanate and small molecular weight diols/diamines. It usually has strong polarity and can form a large number of hydrogen bonds between molecular chains. It often exists in the form of aggregation, which controls the hardness and strength of polyurethane materials. and heat resistance, etc. Diversified structure, excellent performance and easy processing and molding characteristics make polyurethane widely used in many fields, usually used as plastics, rubber, fibers, adhesives, synthetic leather and waterproof materials. The output of polyurethane ranks sixth among polymer materials in the world, but most of the polyurethanes currently used are non-degradable under natural conditions, so recycling is difficult and environmental pollution is a serious problem. Many countries in the world have legislated to restrict the use of disposable non-degradable plastics, which has greatly promoted the research and development of degradable polyurethane. The development of degradable polyurethane can be divided into several stages such as blending with natural substances, blending after modification, copolymerization with natural substances, and molecular chain design according to the time sequence and the degree of technological development. Molecular chain design is a method of preparing degradable polyurethane by designing the soft segment (polyether (ester) polyol) and hard segment (isocyanate and chain extender) in the polyurethane molecular chain to be degradable respectively. It is well known that the controllable introduction of ester bonds (especially aliphatic ester bonds) into the backbone of polymers can endow materials with degradable properties under specific (acidic, basic or biological) conditions. However, for polyether polyurethane, limited by the strong alkaline environment used in the current polyether synthesis process, the introduction of ester bonds in the polyether main chain will induce a violent transesterification reaction, which makes the polyether chain grow slowly and the structure can be changed. Decreased control. Therefore, the degradability of polyether polyurethane mainly relies on the use of polyether-polyester (polycaprolactone, polyvalerolactone, polylactide) block copolymers, or with ester bonds/acetal groups isocyanate, chain extender. However, the synthesis of polyether-polyester block copolymers needs to be achieved through the ring-opening polymerization of lactone monomers initiated by conventional polyether diols, or the macromolecular coupling reaction of polyethers and polyesters. Limited by the low end-group reactivity of macromolecular initiators/monomers, the synthesis of polyether-polyester block copolymers requires more solvents, consumes more energy, and has low yields. More seriously, the introduction of a polyester block at the end of the polyether chain will reduce the flexibility of the molecular chain, thereby affecting the properties of polyurethane such as high elasticity. On the other hand, special isocyanates and chain extenders with ester bonds/acetals can only be obtained through multi-step small-molecule reactions, which are cumbersome and expensive, and are not suitable for large-scale production. Chinese invention patent "A method for controllable preparation of polyether using carboxylic acid as initiator" (CN 201910004162.5), proposes to use carboxylic acid type catalyst/initiator system to implement controllable ring-opening polymerization of epoxy monomers to prepare esterification A method for polyether polyols. The carboxylic acid type catalyst/initiator system uses carboxylic acid compound as initiator, Lewis acid-base pair constructed by organic base and alkyl boron as catalyst system, which can effectively inhibit transesterification reaction and controllable in polyether chain end/chain Introduce aliphatic ester bonds. But it was not used for further preparation of degradable polyether polyurethane.

SUMMARY OF THE INVENTION

In view of the above shortcomings and deficiencies in the prior art, the primary purpose of the present invention is to provide a method for preparing a degradable polyether polyurethane. The method of the invention utilizes the esterified polyether polyol synthesized by the carboxylic acid type initiator to polymerize with the isocyanate, and controllably introduces the ester bond into the main chain of the polymer, so as to endow the material with degradable properties.

Another object of the present invention is to provide a degradable polyether polyurethane prepared by the above method.

The object of the present invention is achieved through the following technical solutions:

A preparation method of degradable polyether polyurethane, comprising the following preparation steps:

(1) Under an inert atmosphere, the epoxy monomer is added to the carboxylic acid-type catalysis/initiating system to react to obtain an esterified polyether polyol; the carboxylic acid-type catalyzing/initiating system includes a carboxylic acid compound, an organic base and an alkane Boron; the carboxylic acid compound refers to a hydroxycarboxylic acid containing at least one carboxyl group or a polycarboxylic acid containing at least two carboxyl groups;

(2) mixing and reacting the esterified polyether polyol obtained in step (1) with isocyanate to obtain a degradable polyether polyurethane.

Further, the epoxy monomers include, but are not limited to, ethylene oxide, propylene oxide, butylene oxide, alkyl ethylene oxide with 3 to 20 alkyl carbon atoms, epichlorohydrin, oxygenated Styrene, butyl glycidyl ether, tert-butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, propargyl glycidyl ether, methacrylate glycidyl ether, epoxycyclohexane.

Further, the carboxylic acid compound is selected from at least one of the following compounds: (1) lactic acid or its homologue, (2) 1-hydroxy straight-chain fatty acid, (3) salicylic acid, (4) malic acid, (5) 2-hydroxycyclohexanecarboxylic acid, (6) 3-hydroxycyclohexanecarboxylic acid, (7) 4-hydroxycyclohexanecarboxylic acid, (8) citric acid, (9) maleic acid, (10) ) fumaric acid, (11) oxalic acid or its homologues, (12) diglycolic acid or its homologues, (13) glutaric acid or its homologues, (14) diunsaturated dicarboxylic acids, ( 15) 2-methyl straight-chain fatty diacid, (16) 3-methyl straight-chain fatty diacid, (17) 3,3-dimethylglutaric acid, (18) 3-ethyl-3-methyl Glutaric acid, (19) 2,2-dimethylsuccinic acid, (20) 2,2-dimethylglutaric acid, (21) 2-oxoglutaric acid, (22) 2,4- Diethylglutaric acid, (23) 1,1-cyclobutanedicarboxylic acid, (24) 1,1-cyclopentanediacetic acid, (25) cyclopentylmalonic acid, (26) 1,1- Cyclohexanediacetic acid, (27) 1,2-cyclohexanedicarboxylic acid, (28) 1,3-cyclohexanedicarboxylic acid, (29) 1,4-cyclohexanedicarboxylic acid, (30) Bicyclo[ 2.2.2] Octane-1,4-dicarboxylic acid, (31) norbornenedioic acid, (32) decahydro-1,4-naphthalenedicarboxylic acid, (33) phthalic acid, (34) m- Phthalic acid, (35) Terephthalic acid, (36) Malic acid or its homologues, (37) 1,2,3-Propanetricarboxylic acid or its homologues, (38) 1,2,4-Benzene Tricarboxylic acid, (39) 1,3,5-benzenetricarboxylic acid, (40) butanetetracarboxylic acid. The specific representative structure is as follows:

Further, the organic base is selected from tertiary amines (DABCO, PMDETA, ME ₆ TREN, sparteine), amidines (DBN, DBU), guanidines (MTBD, TMG, PMG), triaminophosphine (HMTP, HETP) , TMAP, TIPAP) or phosphazene base (BEMP, t-BuP ₁ , t-BuP ₂ , EtP ₂ , t-BuP ₄ ) and the like. The specific structure is as follows:

Further, the alkyl boron is selected from B-isopininyl-9-borabicyclo[3.3.1]nonane (S-Alphine-Borane), tri-sec-butylborane (T s BuB), tri-sec-butyl borane (T ^s BuB), Isopropyl borane (T ⁱ PrB), trimethyl borane (TMB) or tri-straight-chain alkyl borane (TAB) having 2 to 8 alkyl carbon atoms. The specific structure is as follows:

Further, the isocyanates include but are not limited to isophenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,6-hexamethylene diisocyanate, Isophorone diisocyanate, tetramethylxylene diisocyanate, tetramethylene diisocyanate, 1,4-diisocyanate cyclohexane, hexahydrotoluene diisocyanate, 1,5-naphthalene diisocyanate, 1-methoxyl phenyl-2,4-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate Phenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4, 4',4"-triphenylmethane triisocyanate, 2,4,6-triisocyanate toluene, 4,4'-dimethyldiphenylmethane-2,2'-5,5'-tetraisocyanate, polymethyl Polyphenylene polyisocyanate.

Further, in the mixing reaction process described in step (2), a small molecule chain extender or a curing agent is further added for the reaction.

Further, the chain extender includes but is not limited to ethylene glycol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-butanediol Hexylene glycol, 1,4-tetramethylethylene glycol, 1,4-dihydroxy-1,2,3,4-tetralin, hydroquinone diether (HQEE), glycerin, trimethylolpropane, Diethylene glycol, triethylene glycol, neopentyl glycol, sorbitol, diethylaminoethanol and other small-molecule alcohol compounds; the curing agent includes but is not limited to 3,3'-dichloro-4,4-diaminodiol Phenylmethane (MOCA), Ethylenediamine (DA), N,N-Dihydroxy(diisopropyl)aniline (HPA), Diaminobenzene, Diaminobiphenyl, Dimethyldiaminobiphenyl, Dimethoxy Small molecular amine compounds such as diaminobiphenyl and dichlorodiaminobiphenyl.

Further, in the mixing reaction process described in step (2), further add reinforced composite materials, accelerators, diluents, plasticizers, toughening agents, thickeners, coupling agents, foaming agents, defoaming agents, At least one of auxiliary materials such as leveling agent, ultraviolet absorber, antioxidant, brightener, fluorescent agent, pigment, filler, etc.

A degradable polyether polyurethane is prepared by the above method.

Further, the degradable polyether polyurethane can be degraded under acidic conditions, alkaline conditions or biological conditions; the acidic conditions refer to perchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid, sulfuric acid, sulfurous acid, At least one of iodic acid, nitric acid, nitrous acid, acetic acid, oxalic acid, phosphoric acid and other inorganic acids; the alkaline conditions refer to potassium hydroxide (KOH), sodium hydroxide (NaOH), barium hydroxide (Ba(OH) ) ₂ ), calcium hydroxide (Ca(OH) ₂ ) and other inorganic bases or at least one of phosphazene bases, amidines (DBN, DBU), guanidines (MTBD, TMG, PMG) and other organic bases; the Biological conditions refer to lipase such as Lipase PS or microbial degradation.

The preparation method of the present invention and the obtained product have the following advantages and beneficial effects:

(1) The method of the present invention utilizes a carboxylic acid initiator to synthesize the esterified polyether polyol, the raw materials are simple and easy to obtain, the price is low, and the stock is abundant in nature, which conforms to the concept of green chemistry and sustainable development.

(2) The method of the present invention utilizes a carboxylic acid type initiator to synthesize the esterified polyether polyol, the reaction is efficient and controllable, the amount of solvent is small, and the product structure is clear.

(3) The method of the present invention utilizes carboxylic acid initiators to synthesize esterified polyether polyols, and the Lewis acid-base pair catalyst system constructed by the organic base and alkyl boron can efficiently catalyze the polymerization reaction of polyether diols and isocyanates, without the need for Purification and removal, optionally with or without step-by-step polymerization catalysts or small molecule chain extenders, curing agents, etc.

(4) The method of the present invention proposes for the first time that esterified polyether polyols are polymerized with small molecules such as isocyanates and chain extenders, and ester bonds are introduced into the main chain of polyurethane, thereby giving it degradable properties.

(5) The method of the present invention utilizes esterified polyether polyol to prepare degradable polyurethane. Compared with the method of polyether-polyester block copolymer, the degradable soft segment is easy to synthesize, has strong designability and high flexibility of molecular chain; On the premise of not affecting the properties of polyurethane, the introduction of a small amount of ester bonds can impart significant degradability to the material.

(6) The method of the present invention utilizes esterified polyether polyol to prepare degradable polyurethane. Compared with the method of introducing ester bond or acetal into isocyanate or small molecule chain extender, no additional small molecule pre-synthesis step is required.

(7) The method of the present invention utilizes the esterified polyether polyol synthesized by blending polycarboxylic acid initiators to prepare degradable polyurethane, which can directly introduce a cross-linked network structure to improve the mechanical properties of the material; after the cross-linking point is degraded, the cross-linked structure disappears , Polyurethane degradation products can be recycled and reused.

(8) The method of the present invention utilizes the mixture of esterified polyether polyol and conventional polyether polyol (blending polyether method or blending alcohol and carboxylic acid initiator method) to prepare degradable polyurethane. The density of ester bonds in the chain can be adjusted to achieve a controllable degradation rate.

Detailed ways

The present invention will be described in further detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

Example 1

In this example, a hydroxy acid is used as an initiator to carry out the ring-opening polymerization of ethylene oxide to synthesize a polyethylene oxide diol (esterified PEG 1 with a single ester bond in the middle of the polymer chain, the number of ester bonds is 1, hereinafter referred to as PEG 1). ePEG 1).

The specific operations are as follows:

In an inert atmosphere, 1 part (molar part) of lactic acid was added to a dry glass reactor, and dry tetrahydrofuran was added to dissolve. Continue to add the tetrahydrofuran solution containing 0.005 part of phosphazene base t-BuP ₁ and 0.025 part of triethylborane, stir and mix evenly. Connect the glass reactor to a vacuum line, remove part of the gas in the bottle, and cool it down with an ice-water bath. Add 45 parts of dry ethylene oxide at 0-4° C., seal the glass reactor, and react at room temperature (20-30° C.) for 4 h. After the completion of the ethylene oxide reaction, it can be seen that a solid product is precipitated in the glass reactor. The reactor was opened under an inert atmosphere (in a glove box, or during the passage of an inert gas), a small amount of reaction product was taken out, added to deuterated chloroform for hydrogen nuclear magnetic resonance spectroscopy ( ¹ H NMR), and further carried out with tetrahydrofuran Dilution was used for size exclusion chromatography (SEC). The theoretical number-average molecular weight M _n,th of polyethylene oxide is 2.0 kg/mol. The molecular weight measured by SEC was 2.1 kg/mol, and the degree of dispersion was 1.10.

Example 2

In this example, glutaric acid is used as the initiator to carry out the ring-opening polymerization of ethylene oxide to synthesize a polyethylene oxide diol (esterified PEG 2 with a diester bond in the middle of the polymer chain, the number of ester bonds is 2, the following called ePEG 2). In this example, the carboxylic acid-based initiator was replaced with 1 part (molar part) of glutaric acid, and other parts were the same as in Example 1. The reactor was sealed and reacted at room temperature for 4 h. The theoretical number-average molecular weight M _n,th of polyethylene oxide is 2.0 kg/mol. The molecular weight measured by SEC was 2.1 kg/mol, and the degree of dispersion was 1.12.

Example 3

In this example, a hydroxy acid is used as an initiator to carry out the ring-opening polymerization of propylene oxide, and a polypropylene oxide diol (esterified PPG 1, the number of ester bonds is 1, hereinafter referred to as ePPG 1) with a single ester bond in the middle of the polymer chain is synthesized. ).

The specific operations are as follows:

In an inert atmosphere, 1 part (molar part) of lactic acid was added to a dry glass reactor, and dry tetrahydrofuran was added to dissolve. Continue to add a tetrahydrofuran solution containing 0.05 part of phosphazene base t-BuP ₂ and 0.15 part of triethylborane, stir and mix evenly. Continue to add 30 parts of dry propylene oxide, seal the glass reactor and react at room temperature for 6h. The reactor was opened under an inert atmosphere (in a glove box, or during the passage of an inert gas), a small amount of the reaction solution was taken out, added to deuterated chloroform for hydrogen nuclear magnetic resonance spectroscopy ( ¹ H NMR), and further carried out with tetrahydrofuran Dilution was used for size exclusion chromatography (SEC). The conversion rate of propylene oxide monomer measured by ¹ H NMR was 100%, and the theoretical number average molecular weight M _n,th of polypropylene oxide was 1.9 kg/mol. The molecular weight measured by SEC was 2.5 kg/mol, and the degree of dispersion was 1.07.

Example 4

In this example, dicarboxylic acid is used as the initiator to carry out the ring-opening polymerization of propylene oxide to synthesize polypropylene oxide diol (esterified PPG 2, the number of ester bonds is 2, hereinafter referred to as PPG 2) with a diester bond in the middle of the polymer chain. ePPG 2). In this example, the carboxylic acid initiator was replaced with 1 part (molar part) of adipic acid, and other parts were the same as those in Example 3. The reactor was sealed and reacted at room temperature for 7 h. The conversion rate of propylene oxide monomer measured by ¹ H NMR was 100%, and the theoretical number average molecular weight M _n,th of polypropylene oxide was 1.9 kg/mol. The molecular weight measured by SEC was 2.6 kg/mol, and the degree of dispersion was 1.06.

Example 5

In this example, tricarboxylic acid is used as the initiator to carry out the ring-opening polymerization of propylene oxide, and the branched polypropylene oxide triol (esterified PPG 3, the number of ester bonds is 3, the esterified PPG 3, the number of ester bonds is 3) Hereinafter referred to as ePPG 3). In this example, the carboxylic acid initiator was replaced with 1 part (molar part) of glyceric acid, and the epoxy monomer was replaced with 50 parts of dry propylene oxide, and the others were the same as those in Example 3. Seal the glass reactor and react at room temperature for 8h. The conversion rate of propylene oxide monomer measured by ¹ H NMR was 100%, and the theoretical number average molecular weight M _n,th of polypropylene oxide was 3.0 kg/mol. The molecular weight measured by SEC was 3.5 kg/mol and the degree of dispersion was 1.05.

Example 6

In this example, a carboxylic acid mixture is used as an initiator to carry out ring-opening polymerization of propylene oxide to synthesize an esterified polypropylene oxide polyol. In this example, adipic acid and glyceric acid are mixed according to a certain molar ratio (0.5/0.5) as an initiator, and the epoxy monomer is replaced with 40 parts of dry propylene oxide. Others are the same as in Example 3. The reactor was sealed and reacted at room temperature for 6 h. The obtained products are esterified polypropylene oxide diol (theoretical number-average molecular weight M _{n, th} is 2.0kg/mol) and esterified polypropylene oxide triol (theoretical number-average molecular weight M _{n, th} is 3.0kg/mol) mol) in a molar ratio of 0.5/0.5 (hereinafter referred to as ePPG 2+3).

Example 7

In this example, a mixture of a dicarboxylic acid and a small molecule diol is used as an initiator to perform ring-opening polymerization of propylene oxide to synthesize a partially esterified polypropylene oxide polyol. In this example, adipic acid and 1,4-butanediol are mixed in a certain molar ratio (0.5/0.5) as an initiator, and the others are the same as in Example 3. The reactor was sealed and reacted with room temperature for 5h. The obtained product is a mixture of esterified polypropylene oxide glycol (theoretical number average molecular weight M _{n, th} is 2.0kg/mol) and conventional polypropylene oxide glycol, and its molar ratio is 0.5/0.5 (hereinafter referred to as ePPG). m).

Example 8

In this example, glutaric acid is used as the initiator to carry out the ring-opening polymerization of butylene oxide to synthesize polybutylene oxide diol (esterified PBG 2, the number of ester bonds is 2, the number of ester bonds is 2, and the polybutylene oxide diol (esterified PBG 2) with a diester bond in the middle of the polymer chain is synthesized. Hereinafter referred to as ePBG 2). In this example, the carboxylic acid initiator was replaced with 1 part (molar part) of glutaric acid, and the epoxy monomer was replaced with 25 parts of dry butylene oxide, and the others were the same as those in Example 3. The glass reactor was sealed and reacted at room temperature for 12h. The conversion rate of butylene oxide monomer measured by ¹ H NMR was 100%, and the theoretical number average molecular weight M _n,th of polybutylene oxide was 2.0 kg/mol. The molecular weight measured by SEC was 2.3 kg/mol, and the degree of dispersion was 1.06.

Example 9

In this example, monoesterified polyethylene oxide ePEG 1 is used as a macromolecular diol, and is reacted with isocyanate of equimolar components to prepare a degradable polyethylene oxide type polyurethane. The specific operations are as follows:

The crude ePEG 1 product, tetrahydrofuran solvent, and diphenylmethane diisocyanate (MDI) were mixed in a mass ratio of 100/20/13, and the reactor was sealed and reacted at room temperature for 3 hours, and the polyurethane was precipitated in tetrahydrofuran. Open the reactor, collect the product and vacuum dry. The molecular weight of the polyurethane measured by SEC was 53.2 kg/mol, and the degree of dispersion was 2.05.

Example 10

In this example, the double-esterified polyethylene oxide ePEG 2 is used as a macromolecular diol, and is reacted with isocyanate of equimolar components to prepare a degradable polyethylene oxide type polyurethane. The polyethylene oxide was replaced with ePEG 2, and the others were the same as in Example 9. The reactor was sealed and reacted at room temperature for 3 h. The molecular weight of the polyurethane measured by SEC was 59.6 kg/mol, and the degree of dispersion was 2.02.

Example 11

In this example, monoesterified polypropylene oxide ePPG 1 is used as a macromolecular diol to react with isocyanate of equimolar components to prepare a degradable polypropylene oxide type polyurethane. The crude product of ePPG 1 and hexamethylene diisocyanate (HDI) were mixed in a mass ratio of 100/9, the reactor was sealed and the reaction was carried out at room temperature for 1 h to obtain the obtained product. The molecular weight of the polyurethane measured by SEC was 5.3 kg/mol, and the degree of dispersion was 2.05.

Example 12

In this example, the diesterized polypropylene oxide ePPG 2 is used as a macromolecular diol to react with isocyanate of equimolar components to prepare a degradable polypropylene oxide type polyurethane. The crude product of ePPG 2 and toluene diisocyanate (TDI) were mixed in a mass ratio of 100/9, the reactor was sealed, and the reaction was carried out at room temperature for 0.5 h. The molecular weight of the polyurethane measured by SEC was 8.5 kg/mol, and the degree of dispersion was 1.93.

Example 13

In this example, the degradable polyethylene oxide type polyurethane is prepared by reacting polypropylene oxide diols with different degrees of esterification and isocyanates with equimolar components. Mix ePPG 1 crude product, ePPG 2 crude product, and toluene diisocyanate (TDI) in a mass ratio of 100/100/18, seal the reactor, and react at room temperature for 0.5 h, that is, it is obtained. The molecular weight of the polyurethane measured by SEC was 7.4 kg/mol, and the degree of dispersion was 2.03.

Example 14

In this example, degradable soft polyurethane is prepared by reacting diesterized polypropylene oxide ePPG 2 with isocyanate as a soft segment and a small molecular diol as a chain extender. The crude product of ePPG 2 and MDI were mixed in a mass ratio of 100/25, the reactor was sealed and reacted at room temperature for 0.5 h. Continue to add 5 parts (mass fraction) of 1,4-butanediol, seal the reactor and react at room temperature for 0.5h, that is, it is obtained.

Example 15

In this example, a degradable rigid polyurethane is prepared by reacting diesterized polypropylene oxide ePPG 2 with isocyanate as a soft segment and a small molecular diamine as a curing agent. The crude product of ePPG 2 and MDI were mixed in a mass ratio of 100/25, the reactor was sealed and reacted at room temperature for 0.5 h. Continue to add 14 parts (mass fraction) of 3,3'-dichloro-4,4-diaminodiphenylmethane (MOCA), then vigorously stir under vacuum for rapid defoaming, and the mixture is solidified at room temperature to obtain.

Example 16

In this example, the reaction of diesterized polypropylene oxide ePPG 2 with isocyanate is used as a soft segment, a small molecular triol is used as a chain extender, and a small molecular diamine is used as a curing agent to prepare a cross-linked degradable polyurethane. The crude product of ePPG 2 and MDI were mixed in a mass ratio of 100/25, the reactor was sealed and reacted at room temperature for 0.5 h. Glycerol (glycerol, VG) and MOCA are mixed in a mass ratio of 2/5, added to the polyurethane prepolymer, then vigorously stirred under vacuum to rapidly defoam, and the mixture is cross-linked and solidified at room temperature to obtain.

Example 17

In this example, the reaction of diesterized polypropylene oxide ePPG 2 with isocyanate is used as a soft segment, a small molecular triol is used as a chain extender, and a small molecular diamine is used as a curing agent to prepare a degradable polyurethane soft foam. The crude ePPG 2 product, toluene diisocyanate (TDI), VG, and ethylenediamine (DA) were mixed in a mass ratio of 100/18/2/1.2, and a foaming agent with a total fraction of 2% was added, and mixed under high-speed stirring, Pour it into a mold for foaming, and that's it.

Example 18

In this example, the reaction of diesterized polypropylene oxide ePPG 2 with isocyanate is used as a soft segment, a small molecular triol is used as a chain extender, and a small molecular diamine is used as a curing agent to prepare a degradable polyurethane rigid foam. Mix the crude ePPG 2 product, MDI, VG, and MOCA according to the mass ratio of 100/25/2/5, add a foaming agent with a total fraction of 2%, mix under high-speed stirring, and pour it into a mold for foaming, that is, .

Example 19

In this example, the triesterified polypropylene oxide ePPG 3 is used as a macromolecular trihydric alcohol to react with an isocyanate of an equimolar component to prepare a cross-linked degradable soft polyurethane. The crude product of ePPG 3 and HDI were mixed in a mass ratio of 100/9, the reactor was sealed and the reaction was carried out at room temperature for 2 h to obtain.

Example 20

In this example, the reaction of triesterified polypropylene oxide ePPG 3 with isocyanate is used as a soft segment, and a small molecular diamine is used as a curing agent to prepare a cross-linked degradable polyurethane flexible foam. The crude ePPG 3 product, TDI, and DA are mixed in a mass ratio of 100/18/3, a foaming agent with a total fraction of 2% is added, mixed under high-speed stirring, and poured into a mold for foaming.

Example 21

In this example, the reaction of tryesterified polypropylene oxide ePPG 3 with isocyanate is used as a soft segment, a small molecular triol is used as a chain extender, and a small molecular diamine is used as a curing agent to prepare a cross-linked degradable rigid polyurethane foam. The crude ePPG3 product, MDI, VG, and MOCA were mixed in a mass ratio of 100/18/2/5, and a foaming agent with a total fraction of 2% was added, mixed under high-speed stirring, and poured into a mold for foaming.

Example 22

In this example, a semi-crosslinked degradable polyurethane is prepared by reacting blended polypropylene oxide polyols with different degrees of esterification and isocyanates in an equimolar amount. The crude product of ePPG 2, the crude product of ePPG 3, and MDI were mixed in a mass ratio of 100/100/25, and then vigorously stirred under vacuum for rapid defoaming, and the mixture was cross-linked at room temperature to obtain.

Example 23

In this example, the cross-linked degradable polyurethane is prepared by reacting blended polypropylene oxide polyols with different degrees of esterification, isocyanate and curing agent. The crude product of ePPG 2, the crude product of ePPG 3, MDI, and MACO were mixed in a mass ratio of 100/100/35/10, then vigorously stirred under vacuum for rapid defoaming, and the mixture was cross-linked and solidified at room temperature to obtain.

Example 24

In this example, a mixture of polypropylene oxide polyols with different esterification degrees prepared by a one-step method is used to react with an isocyanate in an equimolar amount to prepare a semi-crosslinked degradable polyurethane. The crude ePPG 2+3 product and MDI obtained in Example 6 were mixed in a mass ratio of 100/12.5, then vigorously stirred under vacuum for rapid defoaming, and the mixture was cross-linked and solidified at room temperature to obtain.

Example 25

In this example, degradable polyurethane is prepared by reacting the blended esterified polypropylene oxide diol and conventional polypropylene oxide with isocyanate and curing agent. The crude ePPG 2 obtained in Example 4, conventional PPG2000, MDI and MACO were mixed in a mass ratio of 100/100/35/10, then vigorously stirred under vacuum for rapid defoaming, and the mixture was cross-linked and solidified at room temperature to obtain. This example shows that the ester bond density of the degradable polyurethane can be adjusted by the blending ratio of the esterified polyether and the conventional polyether, so as to achieve a controllable degradation rate.

Example 26

In this example, degradable polyurethane is prepared by reacting the esterified polypropylene oxide diol prepared by one-step method and conventional polypropylene oxide mixture with isocyanate and curing agent. The crude ePPG m product, MDI and MACO obtained in Example 7 were mixed in a mass ratio of 100/25/14, then vigorously stirred under vacuum for rapid defoaming, and the mixture was cross-linked and cured at room temperature to obtain. This example illustrates that the ester bond density of the degradable polyurethane can be adjusted by the blending ratio of acid/alcohol used to carry out the ring-opening polymerization of epoxy monomers, thereby achieving a controllable degradation rate.

Example 27

In this example, degradable soft polyurethane is prepared by reacting diesterized polybutylene oxide ePBG 2 with isocyanate as a soft segment and a small molecular diol as a chain extender. The crude ePBG 2 product and MDI were mixed in a mass ratio of 100/25, the reactor was sealed and the reaction was carried out at room temperature for 0.5 h. Continue to add 5 parts (mass fraction) of 1,4-butanediol, seal the reactor and react at room temperature for 0.5h, that is, it is obtained.

Example 28

This example is the degradation of degradable polyurethane under alkaline conditions. The specific operations are as follows: 95 grams of tetrahydrofuran and 5 grams of sodium hydroxide are added to the 250mL flask, and stirring is started, and then 1 gram (thickness 2mm, width 2-3mm) of the obtained polyurethane in Example 15 is put into the solution, and the oil The temperature of the bath is heated, and the internal temperature is controlled at 60-80°C, and the timing is started until the degradation is complete (the solid is completely dissolved in the solution, and a light yellow solution is obtained), and the recording time is 1 hour.

Example 29

This example is the degradation of cross-linked degradable polyurethane under acidic conditions. The specific operations are as follows: 95 grams of tetrahydrofuran solution and 5 grams of concentrated hydrochloric acid are added to the 250mL flask, and stirring is started, and then 0.3 grams (thickness 2mm, width 2-3mm) of the obtained rigid polyurethane foam in Example 21 is put into the solution In the oil bath, the temperature is controlled at 45-80 °C, and the timing is started until the degradation is complete (the solid is completely dissolved in the solution to obtain a colorless solution), and the recording time is 3 hours. Heating was continued for 8 hours, and the polyether chain ends were completely degraded into small molecules under acidic conditions.

Example 30

This example is the degradation of degradable polyurethane under the catalysis of biological enzymes. The specific operation is as follows: Lipase PS lipase is dissolved in PBS buffer (0.14M, pH=7.4), and the solution is configured to have a concentration of 1 g/L. 1 gram (thickness 2mm, width 2-3mm) of the obtained polyurethane in Example 26 was put into the solution, and stirred at room temperature, and the timing was started until the degradation was complete (the solid was completely dissolved in the solution to obtain a colorless solution), record Time 15 minutes.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims (10)

1. a preparation method of degradable polyether type polyurethane is characterized in that comprising the following preparation steps: (1) Under an inert atmosphere, the epoxy monomer is added to the carboxylic acid-type catalysis/initiating system to react to obtain an esterified polyether polyol; the carboxylic acid-type catalyzing/initiating system includes a carboxylic acid compound, an organic base and an alkane Boron; the carboxylic acid compound refers to a hydroxycarboxylic acid containing at least one carboxyl group or a polycarboxylic acid containing at least two carboxyl groups; (2) mixing and reacting the esterified polyether polyol obtained in step (1) with isocyanate to obtain a degradable polyether polyurethane. 2. the preparation method of a kind of degradable polyether type polyurethane according to claim 1, is characterized in that: described epoxy monomer refers to ethylene oxide, propylene oxide, butylene oxide, alkyl carbon Alkyl ethylene oxide having 3 to 20 atoms, epichlorohydrin, styrene oxide, butyl glycidyl ether, tert-butyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, alkyne At least one of propyl glycidyl ether, methacrylic acid glycidyl ether and epoxy cyclohexane. 3. the preparation method of a kind of degradable polyether polyurethane according to claim 1, is characterized in that described carboxylic acid compound is selected from at least one in following compound: (1) lactic acid or its homologue, (2) ) 1-hydroxy straight-chain fatty acid, (3) salicylic acid, (4) malic acid, (5) 2-hydroxycyclohexanecarboxylic acid, (6) 3-hydroxycyclohexanecarboxylic acid, (7) 4-hydroxycyclohexane Hexanecarboxylic acid, (8) citric acid, (9) maleic acid, (10) fumaric acid, (11) oxalic acid or its homologue, (12) diglycolic acid or its homologue, (13) ) glutaric acid or its homologue, (14) diunsaturated dicarboxylic acid, (15) 2-methyl straight-chain aliphatic diacid, (16) 3-methyl straight-chain aliphatic diacid, (17) 3 ,3-Dimethylglutaric acid, (18)3-ethyl-3-methylglutaric acid, (19)2,2-dimethylsuccinic acid, (20)2,2-dimethylpentane Diacid, (21) 2-oxoglutaric acid, (22) 2,4-diethylglutaric acid, (23) 1,1-cyclobutanedicarboxylic acid, (24) 1,1-cyclopentanedioic acid Alkanediacetic acid, (25) Cyclopentylmalonic acid, (26) 1,1-cyclohexanediacetic acid, (27) 1,2-cyclohexanedicarboxylic acid, (28) 1,3-cyclohexane Dicarboxylic acid, (29) 1,4-cyclohexanedicarboxylic acid, (30) Bicyclo[2.2.2]octane-1,4-dicarboxylic acid, (31) Norbornenedioic acid, (32) Decahydro -1,4-Naphthalenedicarboxylic acid, (33) Phthalic acid, (34) Isophthalic acid, (35) Terephthalic acid, (36) Malonic acid or its homologue, (37) 1,2 , 3-propanetricarboxylic acid or its homologue, (38) 1,2,4-benzenetricarboxylic acid, (39) 1,3,5-benzenetricarboxylic acid, (40) butane tetracarboxylic acid. 4. the preparation method of a kind of degradable polyether polyurethane according to claim 1, is characterized in that: described organic base is selected from tertiary amine, amidine, guanidine, triaminophosphine or phosphazene base; The base boron is selected from the group consisting of B-isopinepinyl-9-borabicyclo[3.3.1]nonane, tri-sec-butylborane, triisopropylborane, trimethylborane or an alkyl group with a carbon number of 2-8 trilinear alkyl boranes. 5. The preparation method of a degradable polyether polyurethane according to claim 1, wherein the isocyanate is selected from isophenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate , 2,6-toluene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylene diisocyanate, tetramethylene diisocyanate, 1,4-diisocyanate cyclohexane Alkane, hexahydrotoluene diisocyanate, 1,5-naphthalene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane Diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3, 3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4',4"-triphenylmethane triisocyanate, 2,4,6-triisocyanate toluene, 4,4'-dimethyl At least one of diphenylmethane-2,2'-5,5'-tetraisocyanate and polymethyl polyphenylene polyisocyanate. 6. the preparation method of a kind of degradable polyether-type polyurethane according to claim 1, is characterized in that: in the mixing reaction process described in step (2), further add at least one in small molecule chain extender and curing agent species react. 7. The preparation method of a degradable polyether polyurethane according to claim 6, wherein the chain extender refers to ethylene glycol, 1,3-propanediol, 1,4-butanediol, 2,3-Butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-tetramethylethylene glycol, 1,4-dihydroxy-1,2,3,4- At least one of tetralin, hydroquinone diether, glycerin, trimethylolpropane, diethylene glycol, triethylene glycol, neopentyl glycol, sorbitol, and diethylaminoethanol; the curing agent refers to 3 ,3'-Dichloro-4,4-diaminodiphenylmethane, ethylenediamine, N,N-dihydroxy(diisopropyl)aniline, diaminobenzene, diaminobiphenyl, dimethyldiaminobiphenyl At least one of benzene, dimethoxydiaminobiphenyl, and dichlorodiaminobiphenyl. 8. the preparation method of a kind of degradable polyether type polyurethane according to claim 1, is characterized in that: in step (2) described in the mixing reaction process, further add reinforced composite material, accelerator, thinner, plasticizer At least one of the agent, toughening agent, thickening agent, coupling agent, foaming agent, defoaming agent, leveling agent, ultraviolet absorber, antioxidant, brightening agent, fluorescent agent, pigment and filler. 9 . A degradable polyether-type polyurethane, characterized in that: it is prepared by the method according to any one of claims 1 to 8 . 10 . The degradable polyether polyurethane according to claim 9 , wherein the degradable polyether polyurethane can be degraded under acidic conditions, alkaline conditions or biological conditions; the acidic conditions refer to: 11 . At least one acidic condition in perchloric acid, hydroiodic acid, hydrobromic acid, hydrochloric acid, sulfuric acid, sulfurous acid, iodic acid, nitric acid, nitrous acid, acetic acid, oxalic acid, and phosphoric acid; the alkaline condition refers to potassium hydroxide , at least one inorganic base condition in sodium hydroxide, barium hydroxide, calcium hydroxide or at least one organic base condition in phosphazene base, amidine, guanidine; described biological condition refers to lipase or microbial degradation a biological condition.