A kind of organosilicon copolymer modified polycarbonate and its preparation process

Abstract

This invention relates to the field of polycarbonate technology and discloses a silicone copolymer-modified polycarbonate and its preparation process. The invention utilizes dimethylsiloxane bis(benzoimide-phenylacetylene) monomer, which is then reacted with ethylene glycol dimercaptoacetate via a mercapto-acetylene click reaction to undergo crosslinking polymerization, yielding a novel hyperbranched imide-silicon copolymer. The addition of an appropriate amount of the silicone copolymer results in excellent dispersibility in the polycarbonate, representing a rigid polyimide structure that improves the tensile strength and flexural properties of the polycarbonate. Simultaneously, the flexible polysiloxane structure within the silicone copolymer provides excellent toughening to the polycarbonate, resulting in better impact resistance and other properties.

Description

Technical Field

[0001] The invention relates to the technical field of polycarbonate, in particular to an organosilicon copolymer modified polycarbonate and a preparation process thereof. Background Art

[0002] Hyperbranched polymers are widely used in the modification of polymer materials due to their unique three-dimensional structure, terminal active functional groups and excellent physical and chemical properties. They can improve the toughness, strength, heat resistance and other properties of materials. The preparation of hyperbranched polymers with new structures and unique properties is a research hotspot.

[0003] Polycarbonate is one of the five major engineering plastics and is widely used in automobile manufacturing, electronics and electrical, building panels, etc. However, single polycarbonate has problems such as poor mechanical strength and low toughness, which limits the development and application of polycarbonate. Patent CN114103358B "A flame retardant reinforced polycarbonate composite board and its preparation method" introduces a styrene-siloxane polymer with a hyperbranched molecular structure on the surface of rigid organic particles to improve the processing performance of PC and LCP systems and improve compatibility, while improving the mechanical properties and flame retardant properties of the prepared polycarbonate composite board. Therefore, using hyperbranched polymers to fill and modify polycarbonate is an effective method to improve the performance of polycarbonate. The present invention provides a hyperbranched imide-organosilicon copolymer for filling and modifying polycarbonate, which significantly improves the mechanical properties of polycarbonate. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] The invention provides a hyperbranched imide-organic silicon copolymer modified polycarbonate, which significantly improves the mechanical properties of the polycarbonate.

[0006] (II) Technical solution

[0007] A process for preparing organosilicon copolymer modified polycarbonate comprises the following steps:

[0008] (1) Add dimethylsiloxane di(phenylimide phenylethyne) and ethylene glycol bis(thioglycolate) to N-methylpyrrolidone, stir to dissolve, add photoinitiator 1173, irradiate with ultraviolet light and stir to react for 1-4 hours, add methanol after the reaction until precipitation, filter, wash with distilled water and ethanol in turn, and obtain a hyperbranched imide-organic silicon copolymer.

[0009] (2) The polycarbonate and the imide-organosilicon copolymer are melt-extruded in a twin-screw extruder at a melt temperature of 220-235° C. and a screw speed of 200-500 rpm, and then hot-pressed in a flat vulcanizer at a temperature of 220-240° C. and a pressure of 10-15 MPa to obtain an organosilicon copolymer-modified polycarbonate.

[0010] Furthermore, the molar ratio of dimethylsiloxane di(phenylimide phenylethynyl) to ethylene glycol bis(thioglycolate) is 1:(1.8-2.3).

[0011] Furthermore, the amount of the photoinitiator 1173 used is 1-2.5% of the total molar amount of the reactants.

[0012] Furthermore, the wavelength of the ultraviolet lamp is 365nm and the power is 400-1000W.

[0013] Furthermore, the amount of the imide-organic silicon copolymer is 1-25% of the mass of the polycarbonate.

[0014] Further, the preparation process of dimethylsiloxane di(benzimidophenylacetylene) comprises the following steps:

[0015] S1: Sodium hydride and 4-hydroxyphthalic anhydride are added to tetrahydrofuran, and the mixture is stirred at room temperature for 2-3 hours, and then dimethyldichlorosilane is added. The reaction is continued by stirring for 18-36 hours. The solvent is removed by rotary evaporation, and the crude product is washed with petroleum ether. The crude product is recrystallized in ethanol to obtain dimethyldi(phthalic anhydride)siloxane intermediate.

[0016] S2. Add water-carrying agent toluene, dimethyl di(phthalic anhydride)siloxane intermediate, p-aminophenylacetylene and catalyst pyridine to N,N-dimethylformamide, and react for 12-24 hours under nitrogen atmosphere protection. The reaction temperature is 110-140°C. After the reaction, add distilled water until a precipitate is precipitated. Filter by suction, wash with deionized water and acetone in turn, and recrystallize the crude product in ethanol to obtain dimethylsiloxane di(phenylimidophenylacetylene).

[0017] Furthermore, the molar ratio of sodium hydride, 4-hydroxyphthalic anhydride and dimethyldichlorosilane in S1 is (2.4-3):(2.3-2.8):1.

[0018] Furthermore, the molar ratio of dimethyl di(phthalic anhydride)siloxane intermediate, p-aminophenylacetylene and pyridine is 1:(2-2.5):(2.2-3).

[0019] (III) Beneficial technical effects

[0020] 1. The present invention utilizes a sodium hydride activation system to react 4-hydroxyphthalic anhydride and dimethyldichlorosilane, and then reacts with p-aminophenylacetylene to obtain a novel dimethylsiloxane di(phenylimide phenylacetylene) monomer, and finally reacts with ethylene glycol bisthioglycolate to undergo a mercapto-alkyne click reaction to perform cross-linking polymerization to obtain a novel hyperbranched imide-organosilicon copolymer.

[0021] 2. Using hyperbranched imide-organic silicone copolymer and polycarbonate filling modification, adding an appropriate amount of organic silicone copolymer has excellent dispersibility in polycarbonate, which means the rigid polyimide structure improves the tensile strength and bending properties of polycarbonate. At the same time, the organic silicone copolymer has a flexible polysiloxane structure, which has a good toughening effect on polycarbonate and has better impact strength and other properties. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Example 1

[0024] (1) 0.12 mol of sodium hydride and 0.115 mol of 4-hydroxyphthalic anhydride were added to 800 mL of tetrahydrofuran, and the mixture was stirred at room temperature for 3 h. Then, 0.05 mol of dimethyldichlorosilane was added. The mixture was stirred and reacted for 18 h. The solvent was removed by rotary evaporation. After washing with petroleum ether, the crude product was recrystallized in ethanol to obtain a dimethyldi(phthalic anhydride)siloxane intermediate.

[0025] (2) Add 200 mL of water-carrying toluene, 0.05 mol of dimethyl di(phthalic anhydride) siloxane intermediate, 0.125 mol of p-aminophenylacetylene and 0.14 mol of catalyst pyridine to 1000 mL of N,N-dimethylformamide, and react for 12 h under nitrogen atmosphere protection at a reaction temperature of 110° C. After the reaction, add distilled water until a precipitate is precipitated, filter, wash with deionized water and acetone in turn, and recrystallize the crude product in ethanol to obtain dimethylsiloxane di(phenylimide phenylacetylene); the preparation reaction formula is:

[0026]

[0027] (3) Add 0.04 mol of dimethylsiloxane di(phenylimide phenylacetylene) and 0.072 mol of ethylene glycol bisthioglycolate (structural formula: ), stirring to dissolve and adding 1.1 mmol of photoinitiator 1173, irradiating with a UV lamp with a wavelength of 365 nm and a power of 1000 W and stirring to react for 1 hour, adding methanol after the reaction until precipitation, filtering, washing with distilled water and ethanol in sequence, to obtain a hyperbranched imide-organosilicon copolymer; the preparation reaction mechanism is as follows:

[0028]

[0029] (4) Polycarbonate and 1% of the mass of polycarbonate imide-organic silicon copolymer are melt-extruded in a twin-screw extruder at a melt temperature of 220° C. and a screw speed of 400 rpm, and then hot-pressed in a flat-plate vulcanizer at a temperature of 230° C. and a pressure of 12 MPa to obtain an organosilicon copolymer-modified polycarbonate.

[0030] Example 2

[0031] (1) 0.14 mol of sodium hydride and 0.13 mol of 4-hydroxyphthalic anhydride were added to 1000 mL of tetrahydrofuran, and the mixture was stirred at room temperature for 2 h. Then, 0.05 mol of dimethyldichlorosilane was added. The mixture was stirred and reacted for 18 h. The solvent was removed by rotary evaporation. After washing with petroleum ether, the crude product was recrystallized in ethanol to obtain a dimethyldi(phthalic anhydride)siloxane intermediate.

[0032] (2) To 500 mL of N,N-dimethylformamide, 150 mL of toluene with water, 0.05 mol of dimethyldi(phthalic anhydride)siloxane intermediate, 0.1 mol of p-aminophenylacetylene and 0.11 mol of catalyst pyridine were added, and the mixture was reacted for 24 h under nitrogen atmosphere at a reaction temperature of 110°C. After the reaction, distilled water was added until a precipitate was precipitated, and the mixture was filtered and washed with deionized water and acetone in turn. The crude product was recrystallized in ethanol to obtain dimethylsiloxane di(phenylimidophenylacetylene).

[0033] (3) Add 0.04 mol of dimethylsiloxane di(phenylimide phenylethyne) and 0.085 mol of ethylene glycol bis(thioglycolate) to 1500 mL of N-methylpyrrolidone, stir to dissolve and add 2.4 mmol of photoinitiator 1173, irradiate with an ultraviolet lamp with a wavelength of 365 nm and a power of 1000 W and stir to react for 2 h, add methanol after the reaction until a precipitate is precipitated, filter, and wash with distilled water and ethanol in turn to obtain a hyperbranched imide-silicone copolymer.

[0034] (4) Polycarbonate and 8% of the mass of polycarbonate imide-organic silicon copolymer are melt-extruded in a twin-screw extruder at a melt temperature of 230° C. and a screw speed of 200 rpm, and then hot-pressed in a flat vulcanizer at a temperature of 240° C. and a pressure of 15 MPa to obtain an organosilicon copolymer-modified polycarbonate.

[0035] Example 3

[0036] (1) 0.15 mol of sodium hydride and 0.14 mol of 4-hydroxyphthalic anhydride were added to 1200 mL of tetrahydrofuran, and the mixture was stirred at room temperature for 3 h. Then, 0.05 mol of dimethyldichlorosilane was added. The mixture was stirred and reacted for 18 h. The solvent was removed by rotary evaporation. After washing with petroleum ether, the crude product was recrystallized in ethanol to obtain a dimethyldi(phthalic anhydride)siloxane intermediate.

[0037] (2) Add 100 mL of water-carrying toluene, 0.05 mol of dimethyldi(phthalic anhydride)siloxane intermediate, 0.1 mol of p-aminophenylacetylene and 0.15 mol of catalyst pyridine to 500 mL of N,N-dimethylformamide, and react for 24 h under nitrogen atmosphere at a reaction temperature of 140°C. After the reaction, add distilled water until a precipitate is precipitated, filter, and wash with deionized water and acetone in turn. The crude product is recrystallized in ethanol to obtain dimethylsiloxane di(phenylimide phenylacetylene).

[0038] (3) Add 0.04 mol of dimethylsiloxane di(phenylimide phenylethyne) and 0.072 mol of ethylene glycol bis(thioglycolate) to 1500 mL of N-methylpyrrolidone, stir to dissolve and add 2.4 mmol of photoinitiator 1173, irradiate with an ultraviolet lamp with a wavelength of 365 nm and a power of 400 W and stir to react for 2 h, add methanol after the reaction until a precipitate is precipitated, filter, and wash with distilled water and ethanol in turn to obtain a hyperbranched imide-silicone copolymer.

[0039] (4) Polycarbonate and an imide-organic silicon copolymer (15% by mass of the polycarbonate) were melt-extruded in a twin-screw extruder at a melt temperature of 220° C. and a screw speed of 500 rpm, and then hot-pressed in a flat-plate vulcanizer at a temperature of 240° C. and a pressure of 10 MPa to obtain an organosilicon copolymer-modified polycarbonate.

[0040] Example 4

[0041] (1) 0.12 mol of sodium hydride and 0.115 mol of 4-hydroxyphthalic anhydride were added to 800 mL of tetrahydrofuran, and the mixture was stirred at room temperature for 2 h. Then, 0.05 mol of dimethyldichlorosilane was added. The mixture was stirred and reacted for 24 h. The solvent was removed by rotary evaporation. After washing with petroleum ether, the crude product was recrystallized in ethanol to obtain a dimethyldi(phthalic anhydride)siloxane intermediate.

[0042] (2) 150 mL of water-carrying toluene, 0.05 mol of dimethyldi(phthalic anhydride)siloxane intermediate, 0.11 mol of p-aminophenylacetylene and 0.13 mol of catalyst pyridine were added to 800 mL of N,N-dimethylformamide, and the mixture was reacted for 18 h under nitrogen atmosphere at a reaction temperature of 130°C. After the reaction, distilled water was added until a precipitate was precipitated, and the mixture was filtered and washed with deionized water and acetone in turn. The crude product was recrystallized in ethanol to obtain dimethylsiloxane di(phenylimide phenylacetylene).

[0043] (3) Add 0.04 mol of dimethylsiloxane di(phenylimide phenylethyne) and 0.085 mol of ethylene glycol bis(thioglycolate) to 1500 mL of N-methylpyrrolidone, stir to dissolve and add 2.4 mmol of photoinitiator 1173, irradiate with an ultraviolet lamp with a wavelength of 365 nm and a power of 400 W and stir to react for 4 h, add methanol after the reaction until precipitation, filter, wash with distilled water and ethanol in turn, and obtain a hyperbranched imide-silicone copolymer.

[0044] (4) Polycarbonate and 20% of the mass of polycarbonate imide-organic silicon copolymer are melt-extruded in a twin-screw extruder at a melt temperature of 235° C. and a screw speed of 300 rpm, and then hot-pressed in a flat-plate vulcanizer at a temperature of 240° C. and a pressure of 12 MPa to obtain an organosilicon copolymer-modified polycarbonate.

[0045] Example 5

[0046] (1) 0.12 mol of sodium hydride and 0.115 mol of 4-hydroxyphthalic anhydride were added to 800 mL of tetrahydrofuran, and the mixture was stirred at room temperature for 3 h. Then, 0.05 mol of dimethyldichlorosilane was added. The mixture was stirred and reacted for 36 h. The solvent was removed by rotary evaporation. After washing with petroleum ether, the crude product was recrystallized in ethanol to obtain a dimethyldi(phthalic anhydride)siloxane intermediate.

[0047] (2) Add 200 mL of water-carrying toluene, 0.05 mol of dimethyldi(phthalic anhydride)siloxane intermediate, 0.125 mol of p-aminophenylacetylene and 0.15 mol of catalyst pyridine to 1000 mL of N,N-dimethylformamide, and react for 18 h under nitrogen atmosphere at a reaction temperature of 130°C. After the reaction, add distilled water until a precipitate is precipitated, filter, and wash with deionized water and acetone in turn. The crude product is recrystallized in ethanol to obtain dimethylsiloxane di(phenylimide phenylacetylene).

[0048] (3) Add 0.04 mol of dimethylsiloxane di(phenylimide phenylethyne) and 0.092 mol of ethylene glycol bis(thioglycolate) to 2000 mL of N-methylpyrrolidone, stir to dissolve and add 3.3 mmol of photoinitiator 1173, irradiate with an ultraviolet lamp with a wavelength of 365 nm and a power of 600 W and stir to react for 2 h, add methanol after the reaction until a precipitate is precipitated, filter, and wash with distilled water and ethanol in turn to obtain a hyperbranched imide-silicone copolymer.

[0049] (4) Polycarbonate and an imide-organic silicon copolymer (25% by mass of the polycarbonate) are melt-extruded in a twin-screw extruder at a melt temperature of 220° C. and a screw speed of 400 rpm, and then hot-pressed in a flat-plate vulcanizer at a temperature of 240° C. and a pressure of 10 MPa to obtain an organosilicon copolymer-modified polycarbonate.

[0050] Comparative Example 1

[0051] (1) Polycarbonate and dimethylsiloxane di(phenylimide phenylethyne) prepared in Comparative Example 3, which is 15% by mass of the polycarbonate, are melt-extruded in a twin-screw extruder at a melt temperature of 220° C. and a screw speed of 400 rpm, and then hot-pressed in a flat-plate vulcanizer at a temperature of 230° C. and a pressure of 15 MPa to obtain a silicone copolymer-modified polycarbonate.

[0052] The tensile properties are tested by a tensile testing machine with a tensile loading speed of 10mm / min, and the implementation standard is GB / T1040.1-2018. The impact resistance is tested by a simply supported beam impact strength testing machine, and the implementation standard is GB / T1043.2-2018. The bending strength is tested by a universal material testing machine with a test speed of 2mm / min, and the implementation standard is GB / T 9341-2008.

[0053] Table 1 Mechanical properties test of polycarbonate

[0054]

[0055] After mechanical property testing, with the increase of the addition amount of imide-organosilicon copolymer, the tensile strength, impact strength and bending performance of polycarbonate showed a trend of first increasing and then decreasing; among them, the polycarbonate prepared in Example 3 added 8% of imide-organosilicon copolymer, and the maximum tensile strength of the polycarbonate reached 73.2MPa, the bending reached 116.2MPa, and the bending modulus reached 3.24GPa; the polycarbonate prepared in Example 4 added 15% of imide-organosilicon copolymer, and the maximum impact strength of the polycarbonate reached 42.6kJ / m 2 ; Comparative Example 1 did not add the silicone copolymer, but only added dimethylsiloxane di(phenylimide phenylethyne). Compared with the various embodiments, there was no obvious effect of improving the mechanical properties of the polycarbonate.

[0056] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A process for preparing organosilicon copolymer modified polycarbonate, characterized in that: The preparation process comprises the following steps: (1) Add dimethylsiloxane di(phenylimide phenylethyne) and ethylene glycol bis(thioglycolate) to N-methylpyrrolidone, stir to dissolve, add photoinitiator 1173, irradiate with ultraviolet light and stir to react for 1-4 hours, add methanol after the reaction until precipitation, filter, wash with distilled water and ethanol in turn, to obtain a hyperbranched imide-organosilicon copolymer; The molar ratio of dimethylsiloxane di(phenylimidophenylethynyl) to ethylene glycol bis(thioglycolate) is 1:(1.8-2.3); (2) The polycarbonate and the imide-organosilicon copolymer are melt-extruded in a twin-screw extruder at a melt temperature of 220-235° C. and a screw speed of 200-500 rpm, and then hot-pressed in a flat vulcanizer at a temperature of 220-240° C. and a pressure of 10-15 MPa to obtain an organosilicon copolymer-modified polycarbonate.

2. The process for preparing the organosilicon copolymer modified polycarbonate according to claim 1, characterized in that: In (1), the amount of photoinitiator 1173 used is 1-2.5% of the total molar amount of the reactants.

3. The process for preparing the organosilicon copolymer modified polycarbonate according to claim 1, characterized in that: The wavelength of the UV lamp is 365nm and the power is 400-1000W.

4. The process for preparing the organosilicon copolymer modified polycarbonate according to claim 1, characterized in that: The amount of the imide-organic silicon copolymer used is 1-25% of the mass of the polycarbonate.

5. The process for preparing the organosilicon copolymer modified polycarbonate according to claim 1, characterized in that: The preparation process of dimethylsiloxane di(benzimidophenylacetylene) comprises the following steps: S1: Sodium hydride and 4-hydroxyphthalic anhydride are added to tetrahydrofuran, and dimethyldichlorosilane is added after stirring at room temperature for 2-3 hours, and the reaction is continued with stirring for 18-36 hours. The solvent is removed by rotary evaporation, and the crude product is recrystallized from ethanol after washing with petroleum ether to obtain dimethyldi(phthalic anhydride)siloxane intermediate; S2. Add water-carrying agent toluene, dimethyl di(phthalic anhydride)siloxane intermediate, p-aminophenylacetylene and catalyst pyridine to N,N-dimethylformamide, and react for 12-24 hours under nitrogen atmosphere protection. The reaction temperature is 110-140°C. After the reaction, add distilled water until a precipitate is precipitated. Filter by suction, wash with deionized water and acetone in turn, and recrystallize the crude product in ethanol to obtain dimethylsiloxane di(phenylimidophenylacetylene).

6. The process for preparing the organosilicon copolymer modified polycarbonate according to claim 5, characterized in that: The molar ratio of sodium hydride, 4-hydroxyphthalic anhydride and dimethyldichlorosilane in S1 is (2.4-3):(2.3-2.8):

1.

7. The process for preparing the organosilicon copolymer modified polycarbonate according to claim 5, characterized in that: The molar ratio of dimethyldi(phthalic anhydride)siloxane intermediate, p-aminophenylacetylene and pyridine is 1:(2-2.5):(2.2-3).

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