阅读说明：本技术 一种共聚碳酸酯及其制备方法 (Copolycarbonate and preparation method thereof ) 是由 魏志涛 王磊 曾伟 王玉彬 黎雷 李凤闯 隋东武 李强 张怀强 于 2020-12-07 设计创作，主要内容包括：本发明涉及一种共聚碳酸酯及其制备方法。具体涉及分子链中含氟橡胶链段、聚硅氧烷链段以及聚碳酸酯链段的新型共聚物及其制备方法。共聚物的结构新颖,将氟橡胶链段、聚硅氧烷链段通过共聚的方式引入聚碳酸酯链段中能够提高常规聚碳酸酯的耐湿热老化性能、耐溶剂性能以及抗冲击性能。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 copolycarbonate and a preparation method thereof. In particular to a novel copolymer of a fluorine-containing rubber chain segment, a polysiloxane chain segment and a polycarbonate chain segment in a molecular chain and a preparation method thereof. The copolymer has a novel structure, and the moisture-heat aging resistance, the solvent resistance and the impact resistance of the conventional polycarbonate can be improved by introducing the fluororubber chain segment and the polysiloxane chain segment into the polycarbonate chain segment in a copolymerization mode. 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 copolycarbonate, wherein said copolycarbonate comprises at least one structure having the formula (i) and the formula (ii):

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

2. the copolycarbonate according to claim 1, wherein:

in the formula (II), m is an integer of 10-140, preferably an integer of 15-100; n is an integer between 10 and 65, preferably between 15 and 50;

in the formula (III), p is an integer of 20-60, preferably 35-50;

preferably, the weight average molecular weight of the copolycarbonate is 21000-58000 g/mol.

3. The copolycarbonate according to claim 1 or 2, wherein: in the structure of the copolycarbonate, the weight percentage of the polycarbonate chain segment in the formula (I) is 70-99%, the weight percentage of the fluororubber chain segment in the formula (II) is 1-20%, and the weight percentage of the chain segment in the formula (III) is 0-10%.

4. The preparation method of the fluorine-containing copolycarbonate is characterized by comprising the following 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 fluororubber, optional double-end hydroxyl silicone oil and an inert organic solvent in a certain proportion in another mixer to prepare a comonomer solution;

(3) carrying out a polymerization reaction: adding the prepared phosgene solution and the comonomer solution into a water phase for polymerization reaction to obtain a copolycarbonate emulsion;

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

5. The method according to claim 4, wherein in the step (1), the end-capping reagent is selected from phenol, p-methylphenol, p-isopropylphenol, p-tert-butylphenol;

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

preferably, the bisphenol a: end-capping agent: alkali metal hydroxide: the molar ratio of water is 1 (0.01-0.05): (2.0-3.0): 20-60).

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

preferably, the molar ratio of the catalyst to the bisphenol A is 0.0001-0.005: 1.

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

in the phosgene solution, the weight ratio of phosgene to inert organic solvent is selected from 1 (5-40);

in the comonomer solution, the weight ratio of the comonomer to the inert organic solvent is selected from 1 (3-6).

8. The preparation method according to any one of claims 4 to 7, wherein the structural formula of the hydroxytelechelic fluororubber is shown as the following formula IV,

9. the preparation method according to any one of claims 4 to 7, wherein the structural formula of the hydroxyl-terminated silicone oil is represented by the following formula V,

10. the production method according to any one of claims 4 to 9, wherein in the step (3), the molar ratio of phosgene to bisphenol A added is (1.1-1.4): 1.

Technical Field

The invention belongs to the technical field of high polymer materials, and relates to copolycarbonate and a preparation method thereof. In particular to a novel copolymer of a fluorine-containing rubber chain segment and a polycarbonate chain segment 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 can be 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 has certain defects, such as relatively poor resistance to wet heat and aging, poor solvent resistance, easy occurrence of stress cracking after touching a solvent, poor impact performance at low temperature, limitation of application in low temperature places, and the like, and the common PC needs to be modified in order to widen the application field thereof.

Chinese patent CN109021534A discloses a high temperature and high humidity resistant polycarbonate composition, in the invention, an organosilicon toughening agent and an oxazoline chain extender are introduced into polycarbonate, and the performance retention rate of a polycarbonate material under the conditions of high temperature and high humidity is improved through the synergistic effect of the organosilicon toughening agent and the oxazoline chain extender. The oxazoline group used in the scheme belongs to toxic organic matters, is not beneficial to environment and health, and reduces the application range of the polycarbonate material. Chinese patent CN109280355A discloses a PC/ABS blending material with hydrolysis resistance, high CTI and high flame retardance, the hydrolysis resistance of PC/ABS is improved by adding carbonized diamine, oxazoline and epoxide into a polycarbonate substrate as hydrolysis stabilizers, but the adopted carbonized diamine is alkaline and can cause degradation of PC to a certain degree in the melt blending process. CN 201911392117.8 discloses a polycarbonate styrene resin alloy resistant to wet heat aging and a preparation method thereof, wherein a wet heat modifier adopted in the specification is hydrophobic fumed silica with an organically treated surface, and the hydrophobic fumed silica is not compatible with the styrene resin alloy well in a melt blending process, so that phase separation is easily caused, and the performance of the material is further influenced.

In summary, it is necessary to improve the resistance to wet heat aging, solvent resistance, impact resistance, etc. of polycarbonate resins, to make up for the disadvantages of conventional polycarbonates, and to broaden the application fields of polycarbonate materials.

Disclosure of Invention

One of the purposes of the invention is to improve the resistance to wet heat aging, solvent resistance, impact resistance and the like of polycarbonate and widen the application field of polycarbonate materials.

In order to achieve the above object, the present invention provides a copolycarbonate comprising a fluororubber segment and a polycarbonate segment in a molecular chain, the copolycarbonate comprising at least the following two structures:

(1) polycarbonate segments of the following formula (I),

and:

(2) a fluororubber segment of the following formula (II),

wherein m is an integer of 10 to 140, preferably an integer of 15 to 100; n is an integer between 10 and 65, preferably an integer between 15 and 50;

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

(3) a polysiloxane segment of the formula (III),

wherein p is an integer of 20 to 60, preferably 35 to 50.

The weight-average molecular weight of the copolycarbonate is 21000-58000 g/mol, preferably 26000-40000 g/mol; in the structure, the weight percentage of the polycarbonate chain segment of the formula (I) is 70-99%, preferably 75-90%, and the weight percentage of the fluorine rubber chain segment of the formula (II) is 1-20%, preferably 5-15%; the weight percentage of the segment represented by the formula (III) is 0 to 10% (for example, 0.5%, 1%, 5%, 10%), preferably 5 to 10%.

It is another object of the present invention to provide a method for preparing the above copolycarbonates, which may be carried out according to conventional methods in the art, which in one embodiment 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 a phosgene solution;

mixing the hydroxyl telechelic fluororubber, optional double-end hydroxyl silicone oil and an inert organic solvent in a certain proportion in another mixer to prepare a comonomer solution;

(3) carrying out a polymerization reaction: dropwise 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 copolycarbonate emulsion;

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

In the method of the present invention, 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;

the bisphenol A: end-capping agent: alkali metal hydroxide: the molar ratio of water is 1 (0.01-0.05): (2.0-3.0): 20-60);

the catalyst is selected from triethylamine, tetrabutylammonium bromide and tetrabutylammonium chloride, and preferably tetrabutylammonium bromide; the molar ratio of the catalyst to the bisphenol A is 0.0001-0.005: 1.

In the method of the present invention, in the step (2), the inert organic solvent is selected from dichloromethane, trichloromethane, dichloroethane, trichloroethane, preferably dichloromethane;

in the phosgene solution, the weight ratio of phosgene to inert organic solvent is selected from 1 (5-40);

in the comonomer solution, the weight ratio of the comonomer to the inert organic solvent is selected from 1 (3-6);

the structural formula of the hydroxyl telechelic fluororubber is shown as the following formula IV,

wherein m and n in the formula IV are defined as the same as the above;

the structural formula of the double-end hydroxyl silicone oil is shown as the following formula V,

wherein p in formula V is as defined above;

the comonomers of formulae IV and V employed in the present invention can be prepared by known techniques or can be used directly in commercial form.

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

the stirring speed during the polymerization reaction is 500-800 rpm.

In the method of the present invention, in the 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, and the oil phase is washed with alkali, acid and water successively, 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 fluorine-containing copolycarbonate improves the humidity resistance, heat resistance, aging resistance, solvent resistance and low-temperature impact resistance of the polycarbonate material, widens the application field of the polycarbonate material, can regulate and control the molecular weight and the composition of the prepared copolymer, has simple steps, and is convenient for industrialized realization.

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.

The analytical evaluation methods referred to in examples or comparative examples are as follows:

(1) the molecular weight is measured by Gel Permeation Chromatography (GPC), and is measured by a gel permeation chromatograph with model number Waters 1515, wherein the solvent is tetrahydrofuran, PS is standard sample, the temperature is 30 deg.C, and the time is 45 min;

(2) the suspension is measured according to the standard test method for Izod impact testing of plastics as specified in ASTM D256-1997;

(3) double 85 aging resistance test

Performing damp-heat aging, namely placing the prepared standard sample strip in a constant-temperature constant-humidity aging box at 85 ℃ and 85% RH (relative humidity) environment, wherein the aging time is 1000 hours, and testing the performance retention rate of the elongation at break and the impact strength of the material according to the standard after the aging is finished;

(4) test for solvent resistance

According to ASTM D543, after applying peanut oil to a test piece (test piece thickness 3.2mm) for tensile strength test in a 1.0% strain jig, the change of appearance was observed and divided into four grades, A (no crack), B (crack), C (severe crack) and D (break), according to the weight of crack;

(5) tensile strength, elongation at break were tested according to ASTM D638, bar size 165 x 13 x 3.2 mm.

Preparatory examples

(1) < preparation of hydroxyl-terminated liquid fluorine 26 rubber >

Refer to published literature { wu meng, qishi cheng, wang kelvin, zhangqu, & yue wintersweet. (2015) }, preparation and application research of hydroxyl-terminated liquid fluorine 26 rubber, rubber technology, 13(012),10-15. };

the structural data of the hydroxyl terminated liquid fluoro 26 rubber are listed in table 1 below,

table 1: structural data of hydroxyl terminated liquid fluoro 26 rubber

Numbering	m	n
			F-1	15	48
F-2	95	16
			F-3	51	30

(2) < eugenol-terminated polyorganosiloxane monomer >

Octamethylcyclotetrasiloxane (1420g, 4.80mol), tetramethyldisiloxane (40.2g, 0.3mol) and clay catalyst Filtrol 20(23.4g, 1.6 wt%) were added to a reaction vessel equipped with a stirrer and a thermometer and stirred for 40 minutes to homogenize the material mixture, then the reaction system was heated up to 50 ℃ at a rate of 5 ℃/min and stirred at that temperature for 3 hours, and then the temperature of the reaction system was continuously heated up to 120 ℃ at a rate of 5 ℃/min and stirred vigorously at that temperature for 5 hours, after which the clay catalyst was removed by filtration. The material after removal of the clay catalyst was then put into a reaction tank equipped with a stirrer and a thermometer and a mixed solution of eugenol (167.2g, 1.02mol) and karstedt's platinum catalyst (0.67g) was added dropwise at a rate of 20 g/min with stirring, after which the reaction was stirred at a temperature of 80 ℃ for 13 hours. Unreacted starting materials were then distilled off at 200 ℃ under reduced pressure to 0.2kPa to give the eugenol-terminated polysiloxane in a yield of 99%, and the degree of polymerization of PDMS was measured by nuclear magnetism to be 48, which is herein defined as PDMS-48 for convenience.

Example 1

342.5g of bisphenol A, 132g of sodium hydroxide, 810g of water and 6.08g of p-tert-butylphenol are added into a mixer protected by nitrogen, and 0.48g of tetrabutylammonium bromide catalyst is added after complete dissolution to form a sodium phenolate brine phase;

163.2g of liquid phosgene and 1631.9g of methylene chloride were added to another mixer and mixed well; then, 20.3g of the hydroxyl-terminated liquid fluorine 26 rubber (No. F-1) prepared in the preparation example and 81g of methylene chloride were mixed in a mixer;

then, putting a sodium phenolate brine phase into a polymerization reactor, then respectively adding the prepared phosgene solution and the hydroxyl-terminated liquid fluorine 26 rubber solution into the polymerization reactor at a stirring speed of 550rpm, simultaneously dropwise adding a 32 wt% sodium hydroxide aqueous solution into a reaction system to keep the pH value of the reaction system at about 11.4, and maintaining the temperature of the reaction system at 35 ℃;

after reacting for 2 hours, separating and purifying the reaction system and removing the organic solvent to obtain the copolycarbonate. The product was analyzed by GPC and had a weight average molecular weight of 22300 and a polydispersity index of 1.48.

Example 2

456.6g of bisphenol A, 200g of sodium hydroxide, 1440g of water and 5.70g of p-tert-butylphenol are added into a mixer protected by nitrogen, and after complete dissolution, 2.58g of tetrabutylammonium bromide as a catalyst is added to form a sodium phenolate brine phase;

237.4g of liquid phosgene and 4747.2g of methylene chloride are added into another mixer and are mixed uniformly; then, 54g of the hydroxyl terminated liquid fluorine 26 rubber (No. F-1) prepared in the preparation example and 243.0g of methylene chloride were mixed in a mixer;

then, putting a sodium phenolate brine phase into a polymerization reactor, then respectively adding the prepared phosgene solution and the hydroxyl-terminated liquid fluorine 26 rubber solution into the polymerization reactor at a stirring speed of 650rpm, simultaneously dropwise adding a 32 wt% sodium hydroxide aqueous solution into a reaction system to keep the pH value of the reaction system at about 11.7, and maintaining the temperature of the reaction system at 33 ℃;

after reacting for 2 hours, separating and purifying the reaction system and removing the organic solvent to obtain the copolycarbonate. The product was analyzed by GPC and had a weight average molecular weight of 32000 and a polydispersity index of 1.39.

Example 3

Adding 228.3g of bisphenol A, 120g of sodium hydroxide, 900g of water and 1.93g of p-tert-butylphenol into a mixer protected by nitrogen, and after complete dissolution, adding 1.61g of tetrabutylammonium bromide serving as a catalyst to form a sodium phenolate brine phase;

128.6g of liquid phosgene and 3857.1g of methylene chloride are added into another mixer and are mixed uniformly; then, 54g of the liquid fluorine 26 rubber (No. F-1) having terminal hydroxyl groups prepared in the preparation example and 270g of methylene chloride were mixed in a mixer;

then, putting a sodium phenolate brine phase into a polymerization reactor, then respectively adding the prepared phosgene solution and the hydroxyl-terminated liquid fluorine 26 rubber solution into the polymerization reactor at the stirring speed of 800rpm, simultaneously dropwise adding a 32 wt% sodium hydroxide aqueous solution into a reaction system to keep the pH value of the reaction system at about 11.4, and maintaining the temperature of the reaction system at 33 ℃;

after reacting for 2 hours, separating and purifying the reaction system and removing the organic solvent to obtain the copolycarbonate. The product was analyzed by GPC and had a weight average molecular weight of 48900 and a polydispersity index of 1.53.

Example 4

The procedure of example 1 was repeated except for changing the hydroxyl-terminated liquid fluorine 26 rubber monomer No. F-1 to the hydroxyl-terminated liquid fluorine 26 rubber No. F-2 prepared in the preliminary example with reference to example 1, and the resulting product was analyzed by GPC and had a weight average molecular weight of 21800 and a polydispersity index of 1.35.

Example 5

The procedure of example 2 was carried out in the same manner as in example 2 except that the hydroxyl-terminated liquid fluorine 26 rubber monomer numbered F-1 was changed to the hydroxyl-terminated liquid fluorine 26 rubber numbered F-2 prepared in the preliminary example with reference to example 2, and the product was analyzed by GPC and had a weight average molecular weight of 30500 and a polydispersity index of 1.38.

Example 6

The procedure of example 3 was repeated in the same manner as in example 3 except that the hydroxyl-terminated liquid fluorine 26 rubber monomer numbered F-1 was changed to the hydroxyl-terminated liquid fluorine 26 rubber monomer numbered F-2 prepared in the preliminary example with reference to example 3, and the product was analyzed by GPC and had a weight average molecular weight of 49800 and a polydispersity index of 1.46.

Example 7

The procedure of example 3 was repeated in the same manner as in example 3 except that the hydroxyl-terminated liquid fluorine 26 rubber monomer was changed to the hydroxyl-terminated liquid fluorine 26 rubber of F-3 prepared in the preliminary example, to analyze the product by GPC, and the weight average molecular weight was 51200 and the polydispersity index was 1.49 in example 3.

Example 8

The operation was carried out in the same manner as in example 3 except that the hydroxyl-terminated liquid fluorine 26 rubber monomer in example 3 was changed to a mixture of the hydroxyl-terminated liquid fluorine 26 rubber (27g) numbered F-2 prepared in preliminary example and the eugenol-terminated polydimethylsiloxane monomer (27g) numbered PDMS-48 prepared in preliminary example 2, and the product was analyzed by GPC to have a weight average molecular weight of 49200 and a polydispersity index of 1.45.

Comparative example

456.6g of bisphenol A, 240g of sodium hydroxide and 1800g of water are added into a mixer with nitrogen protection for mixing, 3.86g of p-tert-butylphenol is added, and after complete dissolution, 3.22g of tetrabutylammonium bromide catalyst is added to form a sodium phenolate brine phase; 128.6257.2 g of liquid phosgene and 7714.2g of methylene chloride are added into another mixer and are uniformly mixed; then, putting a sodium phenolate brine phase into a polymerization reactor, then adding a prepared phosgene solution into the polymerization reactor at a speed of 100g/min under a stirring speed of 700rpm, simultaneously dropwise adding a 32 wt% sodium hydroxide aqueous solution into a reaction system to keep the pH value of the reaction system at 11.6, and maintaining the temperature of the reaction system at 33 ℃; after reacting for 2 hours, separating and purifying the reaction system and removing the organic solvent to obtain the dry polycarbonate. The yield was determined to be 99% and the product was analyzed by GPC as having a weight average molecular weight of 46800 and a polydispersity index of 1.58.

The performance tests of the above examples and comparative examples are shown in the following table:

the comparison of the data shows that compared with the conventional polycarbonate, the polycarbonate copolymer has high notch impact strength, good resistance to heat and humidity aging and good solvent resistance, and the fluororubber chain segment with excellent performance is introduced into the polycarbonate chain segment, so that the performance of the polycarbonate is effectively improved, and the application field of the material is widened.

In a preferred embodiment, a certain amount of polysiloxane chain segments are introduced into a molecular chain, and the molecular chain is flexible polysiloxane, so that the impact resistance of the fluorine-containing copolycarbonate can be further improved.

It will be appreciated by those skilled in the art that modifications or adaptations to the invention may be made in light of the teachings of the present specification. Such modifications or adaptations are intended to be within the scope of the present invention as defined in the claims.