阅读说明：本技术 聚异丁烯基聚碳酸酯共聚物及其制备方法 (Polyisobutylene-based polycarbonate copolymer and preparation method thereof ) 是由 魏志涛 王磊 曾伟 王玉彬 黎雷 李凤闯 于 2020-07-20 设计创作，主要内容包括：本发明涉及一种新型聚异丁烯基聚碳酸酯共聚物及其制备方法。具体涉及分子链中含聚异丁烯链段、聚异丁烯-聚四氢呋喃共聚嵌段、聚碳酸酯链段的新型共聚物及其制备方法。此共聚物的结构新颖,将聚异丁烯链段引入聚碳酸酯链段中能够提高常规聚碳酸酯的抗冲击性能、耐刮擦性能、耐碱性,氧化/水解稳定性,降低吸水率,改善加工性能。本发明采用共聚单体与聚碳酸酯低聚物在催化剂作用下共缩聚的方式制备,操作简单,易于实现,可用于工业化生产中。(The invention relates to a novel polyisobutenyl polycarbonate copolymer and a preparation method thereof. In particular to a novel copolymer containing a polyisobutylene chain segment, a polyisobutylene-polytetrahydrofuran copolymerization block and a polycarbonate chain segment in a molecular chain and a preparation method thereof. The copolymer has a novel structure, and the introduction of the polyisobutylene chain segment into the polycarbonate chain segment can improve the impact resistance, scratch resistance, alkali resistance and oxidation/hydrolysis stability of the conventional polycarbonate, reduce the water absorption and improve the processing performance. The invention adopts the way of copolycondensation of the comonomer and the polycarbonate oligomer under the action of the catalyst, has simple operation and easy realization, and can be used in industrial production.)

1. A novel polyisobutenyl polycarbonate copolymer, wherein the novel polyisobutenyl polycarbonate comprises at least one compound having the structure represented by formula (I) and formula (II):

optionally, the structure shown in formula (III) is also included:

2. the polycarbonate copolymer of claim 1, wherein:

in the formula (II), n₁And n₂The sum of the total number is an integer selected from 10 to 200, preferably an integer from 18 to 90;

in formula (III), q is an integer of 10 to 100, preferably 20 to 50;

s₁and s₂The sum is an integer between 10 and 70, preferably an integer between 14 and 50;

in the polyisobutene chain segment shown in the formula (II), B is a residue of a cationic polymerization bifunctional initiator;

R₁and R₂Each independently is C₁-C₁₆Alkyl radical, C₃-C₁₆Cycloalkyl radical, C₂-C₁₆Alkenyl radical, C₃-C₁₆Cycloalkenyl radical, C₂-C₁₆Alkynyl, C₃-C₁₆Cycloalkynyl or C₆-C₁₈Aryl, preferably C₁-C₁₆Alkyl radical, C₂-C₁₆Alkenyl, wherein R₁Or R₂Independently at each occurrence, is optionally substituted with one or more substituents selected from halogen, cyano, nitro, dialkylamino, trialkylamino, C₁-C₁₆Alkoxy and C₁-C₁₆Substituted with a haloalkyl group;

preferably, the weight average molecular weight of the polycarbonate copolymer is 20000 to 55000g/mol, more preferably 25000 to 35000 g/mol.

3. The polycarbonate copolymer of claim 1 or 2, wherein: in the polycarbonate copolymer, the weight percentage of the structure (I) is 70-99%, preferably 75-90%, and the weight percentage of the structure (II) is 1-20%, preferably 5-15%; the weight percentage of the structure (III) is 0-10%, preferably 5-10%.

4. A method for preparing a polyisobutenyl polycarbonate copolymer, comprising the steps of:

(1) preparing a water phase: mixing bisphenol A, a blocking agent, alkali metal hydroxide and water according to a certain molar ratio, and adding a catalyst to form a water phase;

(2) preparing an oil phase: mixing liquid phosgene and an inert organic solvent in a mixer according to a certain proportion to prepare phosgene solution; mixing hydroxyl telechelic polyisobutylene and optional polyisobutylene-polytetrahydrofuran diol with inert organic solvent in a certain proportion in another mixer to prepare comonomer solution;

(3) carrying out a polymerization reaction: slowly adding the prepared phosgene solution and the comonomer solution into the water phase at a certain stirring speed to carry out polymerization reaction to obtain a polyisobutenyl polycarbonate copolymer emulsion;

(4) and (3) post-treatment: purifying the copolymer emulsion prepared in the step (3) and removing the organic solvent to obtain the product.

5. The method according to claim 4, wherein in the step (1), the end-capping reagent is selected from phenol, p-methyl phenol, p-isopropyl phenol, p-tert-butyl phenol, preferably p-tert-butyl phenol;

the alkali metal hydroxide is selected from potassium hydroxide, sodium hydroxide, lithium hydroxide and cesium hydroxide, preferably sodium hydroxide;

preferably, the bisphenol a: end-capping agent: alkali metal hydroxide: the molar ratio of water is selected from 1 (0.01-0.03): (2.0-3.0): 25-50).

6. The preparation method according to claim 4 or 5, wherein in the step (1), the catalyst is selected from triethylamine, tetrabutylammonium bromide, tetrabutylammonium chloride, preferably tetrabutylammonium bromide;

preferably, the molar ratio of catalyst to bisphenol A is from 0.0001 to 0.006:1, more preferably from 0.001 to 0.005: 1.

7. The process according to any one of claims 4 to 6, wherein in step (2), the inert organic solvent is selected from dichloromethane, trichloromethane, dichloroethane, trichloroethane, preferably dichloromethane;

the weight ratio of the phosgene to the inert organic solvent is 1 (5-40), preferably 1 (10-30);

the weight ratio of the comonomer to the inert organic solvent is 1 (3-6), preferably 1 (4-5).

8. The preparation method according to any one of claims 4-7, wherein the weight average molecular weight of the hydroxytelechelic polyisobutylene is 500-12000, the polydispersity index is less than 2.0, preferably the weight average molecular weight is 1000-5000, and the polydispersity index is less than 1.5;

the weight average molecular weight of the polyisobutylene-polytetrahydrofuran diol is 1000-11000, the polydispersity index is less than 2.0, the weight average molecular weight is preferably 2000-6000, and the polydispersity index is less than 1.5.

9. The production method according to any one of claims 4 to 8, wherein in the step (3), the phosgene and the bisphenol A are added in a molar ratio of (1.1-1.4):1, preferably (1.1-1.3): 1.

10. The production process according to any one of claims 4 to 9, wherein in the step (3), the reaction system is maintained at a pH of 11 to 12 and a temperature of 30 to 35 ℃ for 2 to 4 hours with an aqueous solution of an alkali metal hydroxide.

Technical Field

The invention belongs to the technical field of high polymer materials, and provides a novel polyisobutylene-based polycarbonate copolymer and a preparation method thereof. In particular to a novel copolymer containing polyisobutylene chain segments and polycarbonate chain segments in a molecular chain and a preparation method thereof.

Background

Polycarbonate (PC) is a high molecular polymer containing carbonate bonds in molecular chains, and can be divided into aliphatic, alicyclic, aliphatic-aromatic and aromatic polycarbonates, wherein the aromatic polycarbonate has excellent mechanical properties, heat resistance, impact toughness, electrical insulation and light transmission, low creep resistance and water absorption, good dimensional stability, excellent dielectric properties and the like, can be used as a thermoplastic engineering plastic and is widely applied to the fields of automobiles, electronic equipment, buildings, office supplies, optical discs, sports equipment, medical care, computers, aerospace and the like. However, common PC also has certain defects, such as relatively poor ozone aging resistance, instability under alkaline conditions, scratch resistance, high water absorption, high melt viscosity, poor processability, and the like, and needs to be modified in order to widen the application field.

CN 201210362398.4 discloses a scratch-resistant polycarbonate and a preparation method thereof, wherein a method of mixing and extruding bisphenol A type polycarbonate and silicon-containing organic matter according to a certain mass ratio is adopted, and the fluidity and the impact resistance of the polycarbonate composition prepared by the scheme are not obviously improved; CN 201711229817.6 discloses a halogen-free flame-retardant scratch-resistant polycarbonate material and a preparation method thereof, which is obtained by blending a certain weight part of polycarbonate, silsesquioxane with a specific functional group, a lubricant and an antioxidant, wherein the silsesquioxane with the specific functional group introduced in the scheme has higher hardness and can not improve the fluidity and the impact resistance of the material; CN 201110023688.1 discloses a high-flow high-impact-resistance scratch-resistance polycarbonate composition and a preparation method thereof, a method of blending and extruding aromatic polycarbonate, styrene-acrylonitrile-butadiene copolymer (ABS), thermoplastic polyurethane elastomer (TPU) and the like according to a certain proportion is adopted, but the synthesis conditions of the flow impact modifier thermoplastic polyurethane elastomer adopted in the scheme are harsh, the cost is higher, and the fluidity and the impact resistance of the prepared polycarbonate composition are to be further improved; CN201710517076.5 discloses a scratch-resistant PC/ABS alloy and a preparation method thereof, wherein PC resin, ABS resin, microcrystalline wax, an antioxidant and a lubricant are uniformly mixed according to a certain proportion, and then are melted, blended and extruded at a certain temperature to obtain the scratch-resistant PC/ABS alloy.

In summary, it is necessary to improve the scratch resistance, impact resistance, alkali resistance, aging resistance, water absorption reduction, processability, etc. of polycarbonate, to make up for the defects of polycarbonate, and to broaden the field of polycarbonate materials.

Disclosure of Invention

One of the purposes of the invention is to improve the scratch resistance, impact resistance, alkali resistance and aging resistance of polycarbonate, reduce water absorption and improve the processability, and provide a novel polyisobutenyl polycarbonate copolymer containing fully saturated polyisobutylene chain segments (PIB) and polycarbonate chain segments in a molecular chain, wherein the novel polyisobutenyl polycarbonate copolymer at least comprises the following two structures:

(1) polycarbonate blocks of the formula (I), and

(2) a polyisobutylene block of the following formula (II),

as a preferred embodiment, the copolymer further comprises the following structure:

(3) a polyisobutylene-polytetrahydrofuran copolymer block containing a polytetrahydrofuran segment represented by the following formula (III),

wherein n is₁And n₂The sum of the total number is an integer selected from 10 to 200, preferably an integer from 18 to 90;

q is an integer between 10 and 100, preferably between 20 and 50;

s₁and s₂The sum is an integer between 10 and 70, preferably an integer between 14 and 50.

In the polyisobutene chain segment shown in the formula (II), B is a cationic polymerization bifunctional initiator residue with the structural formula

R¹、R²、R³、R⁴Identical or different and each independently is hydrogen, methyl, ethyl, isopropyl, tert-butyl or phenyl, R¹、R²、R³、R⁴Preferably methyl;

in the polyisobutene segment of the formula (II), R₁And R₂Each independently is C₁-C₁₆Alkyl radical, C₃-C₁₆Cycloalkyl radical, C₂-C₁₆Alkenyl radical, C₃-C₁₆Cycloalkenyl radical, C₂-C₁₆Alkynyl, C₃-C₁₆Cycloalkynyl or C₆-C₁₈Aryl, preferably C₁-C₁₆Alkyl radical, C₂-C₁₆An alkenyl group; wherein R is₁Or R₂Independently at each occurrence, is optionally substituted with one or more substituents selected from halogen, cyano, nitro, dialkylamino, trialkylamino, C₁-C₁₆Alkoxy and C₁-C₁₆Haloalkyl groups.

The weight-average molecular weight of the novel polyisobutenyl polycarbonate copolymer is 20000-55000 g/mol, preferably 25000-35000 g/mol; in the copolymer structure, the weight percentage of the polycarbonate block with the structure (I) is 70-99%, preferably 75-90%, and the weight percentage of the polyisobutylene block with the structure (II) is 1-20%, preferably 5-15%; the weight percentage of the block of structure (III) is 0 to 10% (for example, 0.5%, 1%, 5%, 10%), preferably 5% to 10%.

Another object of the present invention is to provide a method for preparing a polyisobutenyl polycarbonate copolymer, which comprises the steps of:

(1) preparing a water phase: mixing bisphenol A, a blocking agent, an alkali metal hydroxide and water according to a certain molar ratio, and adding a catalyst after the bisphenol A is completely dissolved to form a water phase;

(2) preparing an oil phase: mixing liquid phosgene and an inert organic solvent in a mixer according to a certain proportion to prepare phosgene solution; simultaneously, mixing hydroxyl telechelic polyisobutylene and optional polyisobutylene-polytetrahydrofuran diol with an inert organic solvent according to a certain proportion in another mixer to prepare a comonomer solution;

(3) carrying out a polymerization reaction: slowly adding the prepared phosgene solution and the comonomer solution into a water phase at a certain stirring rate to carry out polymerization reaction, simultaneously keeping the pH of a reaction system at 11-12 by using an alkali metal hydroxide aqueous solution, keeping the temperature of the reaction system at 30-35 ℃, and reacting for 2-4 hours to obtain novel polyisobutylene-based polycarbonate copolymer emulsion;

(4) and (3) post-treatment: purifying the novel polyisobutene-based polycarbonate copolymer emulsion prepared in the step (3) and removing the organic solvent to obtain a product.

In the step (1), the end capping agent is selected from one or more of phenol, p-methyl phenol, p-isopropyl phenol and p-tert-butyl phenol, preferably p-tert-butyl phenol;

the alkali metal hydroxide is selected from one or more of potassium hydroxide, sodium hydroxide, lithium hydroxide and cesium hydroxide, and is preferably sodium hydroxide;

the bisphenol A: end-capping agent: alkali metal hydroxide: the molar ratio of water is 1 (0.01-0.03): (2.0-3.0): 25-50), preferably 1 (0.012-0.027): (2.2-3.0): 30-50);

the catalyst is selected from one or more of triethylamine, tetrabutylammonium bromide and tetrabutylammonium chloride, and tetrabutylammonium bromide is preferred; the molar ratio of catalyst to bisphenol A is from 0.0001 to 0.006:1, preferably from 0.001 to 0.005: 1.

In the step (2), the inert organic solvent is selected from one or more of dichloromethane, trichloromethane, dichloroethane and trichloroethane, and is preferably dichloromethane; the weight ratio of phosgene to inert organic solvent is selected from 1 (5-40), preferably 1 (10-30); the weight ratio of comonomer to inert organic solvent is selected from 1 (3-6), preferably 1 (4-5).

The weight average molecular weight of the hydroxyl telechelic polyisobutylene is 500-12000, the polydispersity index is less than 2.0, preferably the weight average molecular weight is 1000-5000, and the polydispersity index is less than 1.5;

the weight average molecular weight of the polyisobutylene-polytetrahydrofuran diol is 1000-11000, the polydispersity index is less than 2.0, the weight average molecular weight is preferably 2000-6000, and the polydispersity index is less than 1.5;

the method for synthesizing the comonomer used in the present invention can be prepared by referring to published patent documents, for the hydroxytelechelic polyisobutylene, CN200780048071.7, and for the polyisobutylene-polytetrahydrofurandiol: [ Zhang Fang, Zhang Spaceflight, Yansuan, et al.

In the step (3), the molar ratio of the phosgene to the bisphenol A is (1.1-1.4) to 1, preferably (1.1-1.3) to 1;

the pH value of the reaction system during the polymerization reaction is kept between 11 and 12, and preferably between 11.5 and 11.7; the stirring rate is 500rpm to 800rpm, preferably 550rpm to 800 rpm.

In step (4), the post-treatment may be performed by a method conventional in the art, for example: the copolymer emulsion is first oil-water separated, the separated oil phase is alkali washed, acid washed and water washed several times, and the solvent is eliminated from the washed oil phase, crushed and dried to obtain qualified powder.

The invention has the beneficial effects that:

the preparation method has simple steps, easy operation and mild conditions, reduces the production cost and improves the efficiency;

according to the method, the prepared novel polyisobutenyl polycarbonate improves the impact resistance, the scratch resistance and the hydrophobicity of a polycarbonate material, reduces the water absorption rate, has good processability, and widens the application field of the polycarbonate material, wherein a molecular chain contains both saturated soft-segment polyisobutylene and hard-segment polycarbonate, and the prepared molecular weight and composition can be regulated and controlled.

Detailed Description

In order to better understand the technical solution of the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples.