CN1580081A - Multi-arm star-type thermoplastic elastomer initiating system - Google Patents

Abstract

The invention refers to a new multi-armed starlike thermoplastic elastomer solicitation system and is applied to the high molecular compound produced by the carbon-carbon dangling bond cationic polymerization reaction. The new solicitation system is composed of the initiator, coinitiator and nucleophilic reagent. It is used to initiate the vinyl monomer for the homopolymerization, block copolymerization, star polymerization and graft copolymerization. The raw material of the solicitation system is cheap and familiar chemical reagents. The product has large molecule weight and good performance and can provide the industrialization of the active cationic polymerizations of olefin compounds with favorable conditions.

Description

Initiation System of Multi-Armed Star Thermoplastic Elastomer

technical field

The present invention relates to a kind of new initiating system, and it is used for the macromolecular compound that carbon-carbon unsaturated bond living cationic polymerization reaction obtains, and more specifically, the present invention relates to a kind of new organic halide compound, co-initiator, affinity Initiation system of living cationic polymerized multi-armed star thermoplastic elastomer composed of nuclear reagents.

Background technique

For living cationic polymerization, due to the high activity of carbocations, the polymerization reaction is prone to various side reactions, making the realization of living cationic polymerization very difficult. In recent years, the research on its initiating system has realized different systems of active cationic polymerization.

So far, the living cationic polymerization systems discovered and reported mainly include:

Organic peroxide/Lewis acid is used as the initiator system, and when CH ₃ Cl or CH ₂ Cl ₂ is used as the solvent, isobutylene is initiated at low temperature;

2,4,4-Trimethyl-2-chloropentane (TMPCl)/TiCl ₄ is the initiator system, CH ₃ Cl and methylcyclohexane are solvents, at low temperature, in N,N-dimethylacetamide In the presence, styrene is initiated;

U.S.P5451647 provides a kind of living cationic polymerization, with organic compound alcohol, ether, ester, or organic halide as initiator, a kind of Lewis acid is co-initiator, in the presence of 2,6-di-tert-butylpyridine, polymerization Produce homopolymers, copolymers or block copolymers;

EP0725095 patent provides a living cationic polymerization system, in the presence of initiators, co-initiators and pyridine or its derivatives, to initiate the polymerization of vinyl monomers.

At present, when different monomers are polymerized, different initiation systems are generally used, and there is a lack of widely applicable initiation systems.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and provide a stable new active cationic initiator system for initiating vinyl monomers for homopolymerization, block copolymerization, star polymerization, and graft copolymerization .

The purpose of the present invention can be achieved through the following measures: the initiating system of the active cation is made of

(1) Initiator, a kind of compound and derivative thereof with following general formula

Wherein R ₂ and R ₃ each represent a hydrogen atom, R ₁ , R ₂ , and R ₃ each represent a C ₁ to C ₈ linear or branched chain alkyl group, R ₂ represents a five-membered, six-membered saturated or unsaturated ring, R ₁ and R ₂ together with the connected carbon atoms form a five-membered, six-membered saturated or unsaturated ring, and X represents halogen;

(2) Co-initiator Lewis acid: SnCl ₄ , BCl ₃ , TiCl ₄ , SbF ₅ , SeCl ₃ , ZnCl ₂ , FeCl ₃ , VCl ₄ , AlRnCl _n-3 , where R represents a straight chain of C ₁ to C ₈ or Branched chain alkyl, n represents an integer of 0-3;

(3) Nucleophile Lewis base: composed of hexahydropyridine or its derivatives, aliphatic amines, and aromatic amines.

The concentration of the initiator is 1mol/L-10 ^-5 mol/L, and the amount of the initiator added depends on the molecular weight of the polymerization product. The preferred initiator is pyromellitic acid chloride.

The concentration of the co-initiator is 10 mol/L-10 ^-4 mol/L, and the amount of the co-initiator is determined by the amount of the initiator. The preferred co-initiator is TiCl ₄ .

The concentration of the nucleophile is 1mol/L-10 ^-5 mol/L, and the amount of the nucleophile is determined by the water content of the system and the amount of the initiator. The preferred nucleophile is hexahydropyridine.

The mixed solvent is CH ₃ Cl or CH ₂ Cl ₂ mixed with any one of cyclohexane, n-hexane, and methylcyclohexane in a volume ratio of 40:60. The preferred mixed solvent is CH ₃ Cl:cyclohexane=40:60 (V:V) mixed solvent, the amount of the mixed solvent added is 1 to 50 times the volume of the polymerized monomer.

The terminator is methanol or ethanol in hydrochloric acid.

Monomers mainly contain vinyl organic compounds, which can be aliphatic, aromatic, ethers, conjugated dienes, etc., such as isobutylene, styrene, indene, vinyl ethers, isoprene, etc.

The living cationic polymerization process is under normal pressure, the reaction temperature is 0～-90°C, and under the protection of dry nitrogen, in a dry and pure reaction vessel, add the mixed solvent, initiator, co-initiator Lewis acid and nucleophile Lewis base in sequence, Aging for 10-60 minutes first, adding vinyl monomer, after reacting for 1 hour, adding terminator, pouring the terminated solution into a large amount of solution, the product is precipitated, filtered or dried.

In the synthesis process, the solvent is added first, and then polymerized according to a certain order of addition. The order of addition is mixed solvent, initiator, co-initiator, nucleophile, and the monomer is added at the same time, or the initiator, co-initiator, and nucleophile are first added and aged for 10 to 60 minutes, and then the monomer is added for polymerization. , the molecular weight of the resulting product is large.

Drawings of the initiator system of active cations (taking pyromellitic acid chloride as an example)

chain triggers:

1. Carbon ion formation:

Compared with the prior art, the present invention has the following advantages:

1. The present invention provides a stable and relatively consistent initiation system for initiating vinyl monomers for homopolymerization, block copolymerization, star polymerization, and graft copolymerization.

2. Using the initiation system of pyromellitic acid chloride, TiCl ₄ , and hexahydropyridine, the molecular weight of the polymer obtained is large.

3. The present invention utilizes common chemical reagents as initiator, co-initiator, nucleophile and mixed solvent, which provides favorable conditions for the industrialization of the synthesis method.

Detailed ways

Example 1: Living Cationic Polymerization of Polyisobutylene

At normal pressure, reaction temperature -70～-90°C, under the protection of dry nitrogen, add 1L of mixed solvent of _CH2Cl2 and cyclohexane in a volume ratio of _40:60 to a dry reaction vessel, and then add 1× 10 ^-3 mol/L pyromellitic chloride, 0.04 mol/L TiCl ₄ , 1.2×10 ^-3 mol/L hexahydropyridine, after aging for 15 minutes, add 1.14 mol/L isobutene, react for 1 hour, add 5% hydrochloric acid in methanol was used for termination, and the terminated solution was poured into a large amount of ethanol solution to precipitate the product, which was filtered and dried.

The polyisobutylene product has a number average molecular weight of 155,000 and a molecular weight distribution of 1.84.

Embodiment 2: multi-arm star polyisobutylene-polystyrene block thermoplastic elastomer

Under normal pressure, reaction temperature -75～-80°C, under the protection of dry nitrogen, add 1L mixed solvent, 0.5×10 ^-3 mol/L pyromellitic acid chloride, 0.02mol/L TiCl _4. Aging 1.2×10 ^-3 mol/L hexahydropyridine for 15 minutes, adding isobutene to keep the concentration at 2.8 mol/L, and reacting for 1 hour, adding end-capping agent 1,1-diphenylethylene to a concentration of 6 ×10 ^-3 mol/L, age for 15 minutes, add plastic hard segment monomer or its concentration is 0.6mol/L, continue to react for 1 hour, add methanol dissolved in 5% HCl to the system to terminate, after termination The solution was poured into a large amount of ethanol solution, the product was precipitated, filtered and dried.

The block thermoplastic elastomer product has a number average molecular weight of 2.3×10 ⁴ , a molecular weight distribution of 2.0, a glass transition temperature of 197°C, a tensile strength of 20 MPa, an elongation of 400%, and a Shore hardness of 45.

At the same time as the patent application for the present invention, a patent was applied for the synthesis method of the initiator system for the living cationic polymerization of polyolefins.

Claims (6)

1. A multi-arm star-shaped thermoplastic elastomer initiation system for polyolefin living cationic polymerization is characterized by comprising the following components in percentage by weight:

(1) initiator: compounds having the general formula and derivatives thereof

Wherein R is₂、R₃Each represents a hydrogen atom, R₁、R₂、R₃Each represents C₁～C₈Straight or branched alkyl, R₂Represents a five-membered, six-membered saturated or unsaturated ring, R₁And R₂Together with the linking carbon atom to form a five-membered, six-membered saturated or unsaturated ring, X represents halogen;

(2) a co-initiator lewis acid; SnCl₄，BCl₃，TiCl₄，SbF₅，SeCl₃，ZnCl₂，FeCl₃，VCl₄，AlRnCl_n-3Wherein R represents C₁～C₈N represents an integer of 0 to 3;

(3) nucleophile lewis base: piperidine or its derivatives, aliphatic amines, aromatic amines; the mol numbers of the initiator, the coinitiator and the nucleophilic reagent are respectively 1 mol/L-10^-5mol/L，10mol/L～10^-4mol/L，1mol/L～10^-5And mol/L, in the synthesisprocess, adding a solvent firstly, and then carrying out polymerization according to a certain feeding sequence.

2. The initiating system of claim 1, wherein: the initiator is benzene tetrachloride.

3. The initiating system of claim 1, wherein: the co-initiator is titanium tetrachloride.

4. The initiating system of claim 1, wherein: the nucleophile is piperidine.

5. The initiating system of claim 1, wherein: the concentration of the initiator is 1 mol/L-10^-5mol/L, the concentration of the coinitiator is 10 mol/L-10^-4mol/L, the concentration of the nucleophilic reagent is 1 mol/L-10^-5mol/L。

6. The initiating system of claim 1, wherein: in the polymerization method, the initiator, the co-initiator, the nucleophilic reagent and the monomer are added simultaneously at one time or the initiator, the co-initiator and the nucleophilic reagent are added firstly and aged for 10-60 minutes, and then the monomer is added for polymerization reaction.