CN110922734A

CN110922734A - Solvent-resistant and low-temperature impact-resistant polycarbonate alloy material and preparation method thereof

Info

Publication number: CN110922734A
Application number: CN201911006296.7A
Authority: CN
Inventors: 徐凯华
Original assignee: Shanghai Huahe Composite Material Co Ltd
Current assignee: Shanghai Huahe Composite Material Co Ltd
Priority date: 2019-10-22
Filing date: 2019-10-22
Publication date: 2020-03-27

Abstract

The invention discloses a solvent-resistant and low-temperature impact-resistant polycarbonate alloy material and a preparation method thereof, and the solvent-resistant and low-temperature impact-resistant polycarbonate alloy material is composed of the following raw materials in parts by weight: 30-70 parts of PC resin, 8-20 parts of PET resin, 5-20 parts of polymer composite microspheres, 1-3 parts of antioxidant and 0.5-2 parts of lubricant, wherein the polymer composite microspheres are composed of the following components in percentage by weight: 3-10 parts of a fluorine-containing acrylate/maleic anhydride block copolymer, 1-7 parts of functionalized fullerene powder and 1-3 parts of a surfactant. The invention has the beneficial effects that: the functionalized polymer composite microsphere master batch is prepared by utilizing an efficient emulsion polymerization process, the fullerene C60 is taken as a core, the fluorine-containing acrylate/maleic anhydride copolymer is taken as a long-chain branched organic-inorganic hybrid polymer composite microsphere, the unique core-shell structure of the functionalized polymer composite microsphere can improve the stability of the PC/PBT alloy material in various chemicals, and the functionalized polymer composite microsphere master batch serving as an acrylate elastomer layer of a microsphere shell also has a good interface compatibilization toughening effect.

Description

Solvent-resistant and low-temperature impact-resistant polycarbonate alloy material and preparation method thereof

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a polycarbonate alloy material with solvent resistance and low-temperature impact resistance and a preparation method thereof.

Background

Polycarbonate (PC resin for short) is a linear thermoplastic polymer material containing carbonate groups on a molecular main chain, and is divided into three types of aliphatic, aliphatic-aromatic and aromatic according to ester group structures, wherein the aromatic has the best use value because the aromatic contains rigid benzene ring groups which can obviously improve the performance defect of low mechanical property caused by flexible ether-oxygen bonds, and the application field of the bisphenol A type polycarbonate resin is the most extensive and deep. Although bisphenol a type PC resin has excellent characteristics such as high transparency, high dimensional stability, high rigidity and high impact resistance, it is difficult to avoid the inherent defect of polycarbonate material, i.e. the flexible ether-oxygen bond on the molecular chain is easy to break under the induction of external chemical solvent, thereby leading to a series of adverse consequences such as PC resin cracking, degradation and severe attenuation of various properties.

The methods for improving the solvent resistance of PC resins can be roughly classified into two types: a chemical reaction method for adjusting the molecular chain structure of the PC resin through copolymerization reaction, and a physical blending method for adding a polymer with a specific structure and a solvent-resistant auxiliary agent. CN106062073B describes a polycarbonate resin resistant to chemical liquids and chemical vapors, which incorporates a polysiloxane during the polymerization stage, forming a polycarbonate-polysiloxane block copolymer, resulting in an improvement in solvent resistance. Although the chemical modification effect is obvious, the technical threshold is high, the process is complex, and the processing equipment requirement is strict, so that the processing cost of the material is high, and the industrial value of the material which can be popularized and applied is greatly limited. In contrast, the way in which polycarbonate is alloyed and the physical modification of the added additives is a hot direction for related research. CN101280099A prepares a two-phase alloy material of polycarbonate/polyamide, which emphasizes improvement of the stability of the alloy material in a xylene solvent, but the improvement effect is limited to the xylene solvent, and the application range is too narrow; CN105860474A adopts the PC/PBT alloying way to improve the solvent resistance of the polycarbonate, but more attention is paid to the improvement of the heat resistance stability of the material; both CN107118531A and CN106893298A are added with PET (polyethylene terephthalate), and the emphasis is on thoroughly playing the promotion and promotion of the solvent resistance of the polyester material to the solvent resistance of the whole alloy material by improving the alloy compatibility. It can be seen from the above physical blending manner that, because the physical blending modification effect is usually significantly lower than that of the chemical modification method, the application range is narrower, the promotion range is not significant, and when the processing dispersion is not good, the effect is further greatly reduced, so that a novel modification method having both chemical modification and physical modification needs to be found to obtain a satisfactory solvent-resistant modification effect.

Disclosure of Invention

The invention aims to fill the blank of the prior technical scheme and provide a polycarbonate alloy material with solvent resistance and low-temperature impact resistance, aiming at the limitation that most of the prior technical means are simply focused on the improvement of solvent resistance, the invention takes the unique core-shell functional polymer hybrid microspheres as the functional additive, improves the surface solvent resistance of the polycarbonate alloy, and simultaneously, the acrylate elastomer layer of the hybrid microspheres also plays the roles of a PC/PET interphase compatilizer and a low-temperature resistant flexibilizer, thereby synergistically improving the chemical resistance and impact resistance of the alloy material, particularly the notch sensitivity in a low-temperature environment.

The purpose of the invention is realized by the following technical scheme:

a polycarbonate alloy material resistant to solvent and low-temperature impact comprises the following raw materials in parts by weight:

the polymer composite microsphere is composed of the following components in percentage by weight: 3-10 parts of a fluorine-containing acrylate/maleic anhydride block copolymer, 1-7 parts of functionalized fullerene powder and 1-3 parts of a surfactant.

The PC resin is bisphenol A polycarbonate resin, the melt index of the PC resin is 8-25 g/10min under the test conditions of 260 ℃ and 5Kg, and the notch impact strength at normal temperature (23 ℃) is more than or equal to 50kJ/m²。

The PET is polyethylene terephthalate resin, and the intrinsic viscosity of the PET is 0.5-1.5 dL/g.

The antioxidant is one or more of organic auxiliary agents with specific structures, such as phosphite ester, hindered phenol, thioester compounds and the like, which can capture free radicals generated by the thermal degradation of polymers.

The preparation method of the polymer composite microsphere comprises the following steps: weighing a certain proportion of a fluorine-containing acrylate monomer and a maleic anhydride monomer, preparing an emulsified solution with water to a concentration of 1: 10-1: 30, adding a high-efficiency surfactant under a high-speed stirring condition, forming a relatively stable monomer emulsion, raising the temperature to 65 ℃, reducing the stirring speed, adding azotized fullerene powder, initiating the polymerization of the anionic emulsion of the monomer, and removing the water contained in the monomer by repeated rotary evaporation treatment after the reaction is finished, thereby obtaining the organic-inorganic hybrid polymer composite microspheres.

The fluorine-containing acrylate monomer is an alkyl fluorocarbon chain micromolecule monomer with the carbon atom number more than or equal to 7.

The fullerene powder is azobenzene grafted fullerene C60, and the purity of the black powder is more than or equal to 98%.

The maleic anhydride monomer is a colorless needle-shaped or flaky crystal organic micromolecule monomer, and the chemical molecular weight is 96.

The surfactant is a sulfonate anionic surfactant containing double long-chain alkyl.

The second purpose of the present invention is to provide a preparation method of the above-mentioned polycarbonate alloy material with solvent resistance and low temperature impact resistance, the method comprises the following steps:

(1) weighing the PC resin, the PET resin and the antioxidant in parts by weight, and uniformly mixing to obtain a mixed raw material:

(2) placing the dried mixed raw materials into a main feeding bin of a double-screw extruder which is tightly meshed and rotates in the same direction, and adding the dried mixed raw materials into a machine barrel of the extruder through a feeding screw; weighing the polymer composite microspheres according to a proportion, and adding the polymer composite microspheres into a machine barrel of an extruder through a lateral feeding screw. The diameter of the screw extruder used was 36mm, the length-diameter ratio L/D was 44, and the temperatures of the zones from the feed port to the head outlet of the main barrel were set as follows: the polycarbonate alloy material with solvent resistance and low temperature impact resistance is obtained after the processes of melt extrusion, granulation, drying and the like are carried out at the temperature of 100 ℃, 220 ℃, 230 ℃, 240 ℃, 230 ℃ and the rotating speed of a main engine of 200 r/min.

The invention has the following beneficial effects:

1. aiming at the limitations of the traditional technical scheme, such as only paying attention to solvent-resistant modification, or losing the mechanical properties of the alloy material while improving the solvent resistance, in particular to the special high-impact characteristic of polycarbonate, the core-shell polymer microsphere which takes azo fullerene molecules with high adsorbability as the core and fluorine-containing acrylate monomers with excellent solvent resistance as the branched structure is prepared by utilizing a high-efficiency emulsion polymerization reaction method, and the formed fluorine-containing acrylate elastomer layer not only can improve the stability of the polycarbonate material in various chemical solvents, and has good effects of capacity increasing and toughening on a PC/PET two-phase structure in the alloy material, therefore, the excellent solvent resistance of PET is further exerted, the impact property defects that the PC material is easy to stress concentrate and crack in a low-temperature environment are overcome, and the chemical resistance and the mechanical property are synergistically improved.

2. The polycarbonate alloy material obtained by the technical scheme of the invention has excellent rigidity and toughness balance performance in the aspect of conventional mechanical properties and by virtue of good compatibilization and toughening effects of the functional polymer microspheres, the bending strength and the bending modulus of the PC/PET alloy material are consistent with or slightly improved than those of conventional materials, and the impact property is remarkably improved, especially the notch impact strength retention rate in a low-temperature environment (minus 30 ℃) is greatly improved to 80-90% from about 20-30% of that of the conventional material, and the low-temperature multiaxial impact is also converted from brittle fracture to ductile fracture, so that the obtained polycarbonate alloy material has excellent low-temperature impact resistance; furthermore, due to the improvement of the compatibility between PET phases and the addition of the fluoropolymer microspheres, the polycarbonate alloy can keep good stability (the soaking cracking time is more than or equal to 60min) in a conventional chemical solvent such as xylene and 10% sodium carbonate, and can keep the non-cracking time of more than 120min when chemical reagents such as automobile detergent, hand cream and sunscreen cream are coated on the surface in the simulation of actual use environment, so that the polycarbonate alloy material is a multifunctional polycarbonate alloy material with outstanding impact resistance and excellent chemical solvent resistance, is particularly suitable for external automobile accessories such as rear wind wings, front and rear bumper decorative strips, ABC column external decorative plates, door handles and the like, and can also be applied to other fields such as household appliance shells, building decorative materials and the like which are complex in use environment and are easy to contact with various chemical reagents.

Detailed Description

The invention is further illustrated by the following specific examples, which are intended to be illustrative only and not limiting.

The raw materials used in the embodiment of the invention are as follows:

PC: the long-chain low-melting-point high-viscosity polycarbonate has a Tanbawa structure, a melt index MFR of 5g/10min (260 ℃ and 5Kg), and a notched impact strength of 56kJ/m²。

CZ-333, Jiangyin industry, 243 ℃ melting point and 0.76dL/g intrinsic viscosity.

Fluorine-containing acrylate: dodecafluoroheptyl acrylate G05, a colorless transparent liquid, the water content of which is less than or equal to 0.5 percent, Harbin snow-Jia Fluorosilicone chemical Co.

Fullerene: azotized graphene TNNRGO, black powder, the particle size of 2-20um, the purity of more than or equal to 98 percent, the nitrogen content of 5-10 percent, and Chinese academy organic chemistry, Inc.

Maleic anhydride: organic small molecular monomer, colorless needle crystal with purity not less than 99%, Sigma-Aldrich company.

Surfactant (b): the dialkyl disulfonate sodium anionic surfactant SM-5B-40 is a red brown transparent liquid, the effective content of which in aqueous solution is 40 percent, Jiangxi Si Mo biochemistry Co.

Antioxidant: dioctadecyl pentaerythritol diphosphite-antioxidant 618, white waxy flake solid, Shanghai Jinhaiyabao Fine chemistry Co., Ltd.

Styrene graft: styrene-acrylonitrile-GMA graft SAG-005 reaction type compatilizer, white particles, with a grafting rate of 1.0%, Jiangsu good easy compatilizer Co.

And (3) product performance testing:

bending property: according to the sample strip dimensions specified in ISO178, the test was carried out after injection moulding of a standard sample strip at a test rate of 2mm/min at normal temperature (23 ℃).

Impact properties: according to the sample strip size specified by ISO179-1 standard, the test is carried out after the standard sample strip is injected, the test is carried out on a simply supported beam impact tester, the notch type is A type, the test is carried out in the environment of normal temperature (23 ℃), then the temperature is reduced to low temperature (-30 ℃), and then the test is carried out, so as to obtain the low-temperature notch impact strength data.

Low-temperature multi-axial impact test: the test was carried out according to ISO6603-2 standard methods, a 150X 100X 3.2mm sample was prepared and run on a Coesfeld multiaxial impact tester, with a constant ambient temperature of-30 ℃, a punch diameter of 20 mm and a total energy of 59.1J.

Chemical resistance test: test pieces of 100X 10X 3.2mm size were prepared, immersed in xylene, 10% sodium carbonate solution, respectively, in a standard environment (23 ℃, 50% RH), and a certain amount of car detergent, hand cream, sunscreen cream were applied to the surface of the pieces, respectively, the cracking of the material surface was observed, and the cracking time was recorded.

Example 1

Weighing a fluorine-containing acrylate monomer, a maleic anhydride monomer and a surfactant according to a certain proportion according to data of example 1 shown in Table 1, preparing an emulsified solution with water at a concentration of 1: 10-1: 30, adding a high-efficiency surfactant under a high-speed stirring condition to form a relatively stable monomer emulsion, raising the temperature to 65 ℃, reducing the stirring speed, adding azotized fullerene powder to initiate anionic emulsion polymerization of the monomers, and removing water contained in the monomer emulsion through repeated rotary evaporation treatment after the reaction is finished, thereby obtaining the organic-inorganic hybrid polymer composite microspheres.

TABLE 1 formulation of polymer composite microspheres (Unit: g)

	Example 1	Example 2	Example 3	Example 4	Example 5
						Fluorine-containing acrylate copolymer	6	3	10	6	8
Fullerene C60 powder	2	7	1	5	4
						Surface active agent	2	1	3	2	2

Example 2

Weighing a fluorine-containing acrylate monomer, a maleic anhydride monomer and a surfactant according to a certain proportion according to data of example 2 shown in Table 1, preparing an emulsified solution with water at a concentration of 1: 10-1: 30, adding a high-efficiency surfactant under a high-speed stirring condition to form a relatively stable monomer emulsion, raising the temperature to 65 ℃, reducing the stirring speed, adding azotized fullerene powder to initiate anionic emulsion polymerization of the monomers, and removing water contained in the monomer emulsion through repeated rotary evaporation treatment after the reaction is finished, thereby obtaining the organic-inorganic hybrid polymer composite microspheres.

Example 3

Example 4

Example 5

TABLE 2 formulation of solvent resistant, low temperature impact resistant polycarbonate composites (unit: g)

Example 6

The PC resin, the PET resin and the antioxidant were weighed and mixed uniformly according to the data of example 6 shown in Table 1 to obtain a mixed raw material.

Placing the dried mixed raw materials into a main feeding bin of a double-screw extruder which is tightly meshed and rotates in the same direction, and adding the dried mixed raw materials into a machine barrel of the extruder through a feeding screw; weighing the polymer composite microspheres according to a proportion, and adding the polymer composite microspheres into a machine barrel of an extruder through a lateral feeding screw. The diameter of the screw extruder used was 36mm, the length-diameter ratio L/D was 44, and the temperatures of the zones from the feed port to the head outlet of the main barrel were set as follows: the polycarbonate alloy material with solvent resistance and low temperature impact resistance is obtained after the processes of melt extrusion, granulation, drying and the like are carried out at the temperature of 100 ℃, 220 ℃, 230 ℃, 240 ℃, 230 ℃ and the rotating speed of a main engine of 200 r/min.

Example 7

The PC resin, the PET resin and the antioxidant were weighed and mixed uniformly according to the data of example 7 shown in Table 1 to obtain a mixed raw material.

Example 8

The PC resin, the PET resin and the antioxidant were weighed and mixed uniformly according to the data of example 8 shown in Table 1 to obtain a mixed raw material.

Example 9

The PC resin, the PET resin and the antioxidant were weighed and mixed uniformly according to the data of example 9 shown in Table 1 to obtain a mixed raw material.

Example 10

The PC resin, the PET resin and the antioxidant were weighed and mixed uniformly according to the data of example 10 shown in Table 1 to obtain a mixed raw material.

Comparative example 1

Weighing PC resin, PET resin and antioxidant according to the data of comparative example 1 shown in Table 1, and mixing uniformly to obtain mixed raw material

Placing the dried mixed raw materials into a main feeding bin of a double-screw extruder which is tightly meshed and rotates in the same direction, and adding the dried mixed raw materials into a machine barrel of the extruder through a feeding screw; the diameter of the screw extruder used was 36mm, the length-diameter ratio L/D was 44, and the temperatures of the zones from the feed port to the head outlet of the main barrel were set as follows: the polycarbonate alloy material is obtained by the processes of melt extrusion, granulation, drying and the like at the temperature of 100 ℃, 220 ℃, 230 ℃, 240 ℃, 230 ℃ and the rotating speed of a main engine of 200 revolutions per minute.

Comparative example 2

Weighing PC resin, PET resin, styrene graft and antioxidant according to the data of comparative example 2 shown in Table 1, and mixing uniformly to obtain mixed raw material

TABLE 3 test results for solvent resistant, Low temperature impact resistant polycarbonate alloy materials

Comparing the material test data of each example 6-10 and comparative example 1-2 in Table 3, it can be seen that the distribution of PET material as the alloy dispersion phase has a great influence on the improvement of mechanical properties and solvent resistance of PC/PET alloy. Comparative example 1 has no compatibilizer, and the low temperature impact performance and solvent resistance are the lowest in each example and comparative example, while example 2 has conventional styrene graft as compatibilizer, the solvent resistance is obviously improved, but the low temperature impact condition is still not good. With the addition of the core-shell structured functionalized polymer microspheres, the compatibility of PC/PET is improved, the fluoroacrylate elastomer layer also provides a strong support for the improvement of impact and solvent resistance, and the low-temperature notched impact strength of the alloy material is from 20kJ/m of that of the comparative example²Lifted to 40kJ/m from left to right²In the above (examples 8 to 10), the multi-axial impact property at low temperature is improved, and not only the impact energy absorption degree is significantly better, but also the fracture mode of the material is improved from brittle fracture to toughness; the most obvious alkali resistance (10% sodium carbonate solution) in the solvent resistance is improved, the cracking time of the solvent resistance is greatly increased from 20min to 45-50min, and the cracking time of the xylene resistance, the sun cream resistance and the hand protection in examples 9 and 10 exceeds the upper limit of the test respectively and is more than 60min and 120 min.

Further comparing the data of the examples, it can be seen that the structural components of the functionalized polymer microspheres also have a direct influence on the improvement effect, specifically, the particle size of the microspheres themselves and the acrylate elastomer as the outer shell layerThe thickness of the bulk layer. In example 6, the fullerene particles as the core are too few, so that the formed polymer shell layer is too thick, and the particle size of the polymer microspheres is large, so that the compatibilization and toughening effects are affected, so that the improvement range of the low-temperature notch impact is not obvious, while the improvement range of the solvent resistance of the alloy material is still not ideal although the improvement range of the mechanical property is not sufficient by increasing the amount of the pure acrylate in example 8. Whereas in examples 9, 10 a relatively reasonable ratio of core-shell monomers was assumed, i.e. fullerene: the acrylic ester is about 1:2 (example 10), so the obtained polymer microsphere has moderate elastomer shell layer and particle size, the performance of the obtained alloy material is the highest in each example, and the low-temperature notch impact strength is 47kJ/m²Compared with the data at normal temperature, the data is only reduced by about 15 percent, and the most difficult performances of alkali resistance and vehicle-used detergent in the solvent resistance test are also optimal, wherein the cracking time of the vehicle-used detergent is greatly increased from 56min in comparative example 1 to 117min, and is very close to the upper limit of the test time.

The polycarbonate alloy material and the preparation method thereof described by the invention are beneficial supplements to the blank field in the multifunctional research of the current polycarbonate alloy material, the functionalized polymer microspheres are prepared in an efficient emulsion polymerization manner, so that the synergistic improvement of the low-temperature impact resistance and the solvent resistance of the PC/PET two-phase alloy material is realized, particularly, the alloy material has broad-spectrum solvent resistance performance, the performance is good in the conventional solvents such as xylene and sodium carbonate alkaline solution, but also has better stability to chemical solvents in daily use environments such as hand cream, sun cream and detergent, the automobile decorative plate is particularly suitable for target fields such as automobile external decorative parts, such as empennages, fenders, front and rear bumpers, ABC pillar decorative plates and the like which have high requirements on environmental stability, and outdoor industrial electronic and electric appliance shells, building decorative materials and the like.

Claims

1. A polycarbonate alloy material with solvent resistance and low-temperature impact resistance is characterized in that: the feed comprises the following raw materials in parts by weight:

2. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the PC resin is bisphenol A polycarbonate resin, the melt index of the PC resin is 8-25 g/10min under the test conditions of 260 ℃ and 5Kg, and the notch impact strength at normal temperature (23 ℃) is more than or equal to 50kJ/m²。

3. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the PET is polyethylene terephthalate resin, and the intrinsic viscosity of the PET is 0.5-1.5 dL/g.

4. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the antioxidant is one or more of organic auxiliary agents with specific structures, such as phosphite ester, hindered phenol, thioester compounds and the like, which can capture free radicals generated by the thermal degradation of polymers.

5. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the preparation method of the polymer composite microsphere comprises the following steps: weighing a certain proportion of a fluorine-containing acrylate monomer and a maleic anhydride monomer, preparing an emulsified solution with water to a concentration of 1: 10-1: 30, adding a high-efficiency surfactant under a high-speed stirring condition, forming a relatively stable monomer emulsion, raising the temperature to 65 ℃, reducing the stirring speed, adding azotized fullerene powder, initiating the polymerization of the anionic emulsion of the monomer, and removing the water contained in the monomer by repeated rotary evaporation treatment after the reaction is finished, thereby obtaining the organic-inorganic hybrid polymer composite microspheres.

6. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the fluorine-containing acrylate monomer is an alkyl fluorocarbon chain micromolecule monomer with the carbon atom number more than or equal to 7.

7. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the fullerene powder is azobenzene grafted fullerene C60, and the purity of the black powder is more than or equal to 98%.

8. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the maleic anhydride monomer is a colorless needle-shaped or flaky crystal organic micromolecule monomer, and the chemical molecular weight is 96.

9. The polycarbonate alloy material with solvent resistance and low-temperature impact resistance according to claim 1, wherein: the surfactant is a sulfonate anionic surfactant containing double long-chain alkyl.

10. The method for preparing the polycarbonate alloy material with solvent resistance and low-temperature impact resistance as claimed in any one of claims 1 to 9, which is characterized in that: the method comprises the following steps: