High-transparency ethanol-resistant PMMA (polymethyl methacrylate) material and preparation method thereof

Abstract

The invention discloses a high-transparency ethanol-resistant PMMA (polymethyl methacrylate) material and a preparation method thereof, and belongs to the technical field of high polymer material modification. Comprising PMMA resin, PA PACM12 resin, an antioxidant and a lubricant, and the high-transparency ethanol-resistant PMMA material is prepared by mixing the components, adding the mixture into a twin-screw extruder, melting, extruding and granulating. A microcrystalline PACM12 group is embedded into PMMA through blending modification, so that a PMMA matrix can be effectively prevented from being invaded by ethanol, the material is prevented from being invaded by high-concentration ethanol, and meanwhile, the transparency of the PMMA material is not influenced after the microcrystalline PACM12 group is added. The invention solves the problems of intolerance to ethanol, fogging and cracking of the transparent shell material of the automobile tail lamp, and can also be used for optical property application.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material modification, and in particular relates to a high-transparency ethanol-resistant PMMA material and a preparation method thereof. Background Art

[0002] PMMA resin is a commonly used material for automobile taillight housings due to its high transparency and high weather resistance. However, it often comes into contact with ethanol-containing car wash liquids during use. Since it is a linear amorphous material, it is easily corroded by ethanol, causing whitening and severe cracking, which seriously affects product quality and traffic safety.

[0003] There are two commonly used solutions to improve the ethanol resistance of automobile taillight covers: one is to apply a corrosion-resistant coating on the surface of the parts. This solution increases the number of steps, reduces the yield rate and causes an increase in cost; the other is to introduce a five-membered or six-membered ring structure during the PMMA polymerization process to prevent the PMMA material from swelling in an ethanol environment and causing cracking and other defects. This solution has high material viscosity, difficult processing, and is prone to yellowing at high temperatures. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a high-transparency ethanol-resistant PMMA material, wherein the PMMA material has excellent ethanol resistance and high transparency.

[0005] Another object of the present invention is to provide a method for preparing a high-transparency ethanol-resistant PMMA material, which has a simple process, convenient operation and control, and is suitable for large-scale industrial production.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A highly transparent ethanol-resistant PMMA material comprises PMMA resin, PA PACM12 resin, antioxidant and lubricant, wherein the PA PACM12 resin accounts for 5-15% of the total mass of the PMMA resin and the PA PACM12 resin.

[0008] Furthermore, the PMMA resin is polymethyl methacrylate.

[0009] Furthermore, the PA PACM12 resin is a linear polyamide containing an alicyclic structure, namely, 4,4-diaminodicyclohexylmethane nylon, and each repeating unit of the molecular chain has two alicyclic rings.

[0010] Furthermore, the antioxidant is a phosphite.

[0011] Furthermore, the antioxidant is one of antioxidant 168, antioxidant 626 and antioxidant TPP.

[0012] Furthermore, the amount of the antioxidant used is 0.05%-0.2% of the total mass of the PMMA resin and the PA PACM12 resin.

[0013] Furthermore, the lubricant is an alcohol ester.

[0014] Furthermore, the lubricant is one of lubricant PETS, lubricant TMP and lubricant DEGS.

[0015] Furthermore, the amount of the lubricant is 0.1%-0.5% of the total mass of the PMMA resin and the PA PACM12 resin.

[0016] Another object of the present invention is achieved by the following technical solution: a method for preparing a highly transparent ethanol-resistant PMMA material, comprising the following steps:

[0017] The PMMA resin, PA PACM12 resin, antioxidant and lubricant are mixed for 5-10 minutes to obtain a uniform mixture; the mixture is added into a twin-screw extruder for melting, extrusion and granulation to obtain a high-transparency ethanol-resistant PMMA material.

[0018] Further, the melt temperature of each zone of the twin-screw extruder is set to 180±5°C, 260±5°C, 260±5°C, 260±5°C, 250±5°C, 250±5°C, 250±5°C, 240±5°C, 250±5°C, 260±5°C;

[0019] The main engine speed of the twin-screw extruder is 400-500r / min.

[0020] Beneficial effects of the present invention:

[0021] The present invention uniformly disperses the PA PACM12 resin in the PMMA resin by co-extrusion. There are two aliphatic rings in each repeating unit of the molecular chain in the PA PACM12 resin, which leads to greater rigidity of the molecular chain, greater steric hindrance in the spatial movement of the chain segments, and difficulty in the movement of the chain segments. Compared with traditional PA materials, it is more difficult to crystallize and only microcrystals can be formed in the system. The microcrystal phase can not only effectively prevent ethanol from invading the PMMA matrix, but also the microcrystals are nanometer-level, do not affect the transmittance of visible light, and do not affect the transparency of the material. 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] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0024] PMMA resin, HD01A produced by Wanhua;

[0025] PA PACM12 resin, produced by Evonik;

[0026] PA 12 resin, produced by Evonik;

[0027] Antioxidant 168, produced by BASF, Germany;

[0028] Lubricant PETS, produced by Shanghai Langzhen.

[0029] The preparation method of the high-transparency ethanol-resistant PMMA material in the following examples and comparative examples is as follows:

[0030] Weigh each component according to the weight ratio in Table 1, mix for 10 minutes to obtain a mixture, add the mixture into a twin-screw extruder, melt, extrude, and granulate to obtain a high-transparency ethanol-resistant PMMA material;

[0031] The twin-screw extruder has a screw diameter of 40 mm and a length-to-diameter ratio of L / D = 40. The screw assembly is combined with a high-dispersion screw block to help PA PACM12 fully disperse in PMMA.

[0032] The melt temperatures of the zones of the twin-screw extruder were set to 185°C, 265°C, 265°C, 255°C, 255°C, 255°C, 245°C, 255°C, 265°C;

[0033] The main engine speed is 500r / min;

[0034] The feeding rate was 100 kg / h.

[0035] Table 1

[0036]

[0037] The PMMA materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were first placed in a blast oven at 85° C. and dried for 3 hours to fully dry the moisture, and then injection molded the specimens and the sample plates on an injection molding machine. The state was adjusted for 24 hours under a standard environment to facilitate performance testing. The test standards and test conditions are as follows:

[0038] Density test: According to ISO 1183-1:2019 standard, the test size is 40*10*4mm;

[0039] Tensile strength test: according to ISO 527-2:2012 standard, the sample size is 135*10*4mm, and the tensile speed is 50mm / min;

[0040] Bending strength and bending modulus test: According to ISO 178:2019 standard, the sample size is 80*10*4mm, the bending speed is 2mm / min, and the span is 64mm;

[0041] Simple supported beam notched impact strength test: according to ISO 179-1:2023 standard, the sample size is 80*10*4mm, A-type notch, 4J pendulum;

[0042] Transparency test: 3mm standard sample, use Palmer 1050+ UV-visible spectrophotometer to test the visible light band (380nm-780nm); transparency ≥90 is considered qualified;

[0043] Ethanol resistance test: standard environment (temperature: 25°C, humidity: 60% RH); test materials: test fixture size (radius R = 198mm), test specimen (ISO 527 / 1A tensile specimen, length 170mm), 90% ethanol solvent (ethanol / water 90:10v / v); after stress is applied, the ethanol resistance is judged by the time to break, and ≥1min is considered qualified;

[0044] The material can only be considered qualified if both transparency and ethanol resistance are qualified.

[0045] The performance test results are shown in Table 2:

[0046] Table 2

[0047]

[0048] It can be seen from Table 2 that the PMMA materials prepared in Examples 1 to 3 not only have good ethanol resistance and transparency, but also have good mechanical properties.

[0049] Comparing Comparative Example 1 with Examples 1 to 3, it can be concluded that the PMMA material obtained by not adding PA PACM12 resin when preparing the PMMA material has poor ethanol resistance; the reason is that there are two aliphatic rings in each repeating unit of the molecular chain of the PA PACM12 resin, which leads to greater rigidity of the molecular chain, greater steric hindrance to the spatial movement of the chain segments, and difficulty in the movement of the chain segments. Compared with traditional PA materials, it is more difficult to crystallize, and only microcrystals can be formed in the system. This microcrystal phase can not only effectively prevent ethanol from invading the PMMA matrix, but also this microcrystal is nanometer-level, does not affect the transmittance of visible light, and does not affect the transparency of the PMMA material.

[0050] Comparison of Comparative Example 2 with Example 2 shows that although adding PA12 resin to PMMA material can make PMMA material resistant to ethanol, its transparency is poor; the reason is that although PA12 can form crystals in the system, thereby effectively preventing ethanol from invading the PMMA matrix, the large size of PA12 crystals cannot guarantee that the PMMA material has good transparency.

[0051] Comparison of Comparative Examples 3-4 with Examples 1-3 shows that the optimal addition ratio of PA PACM12 resin is limited to 5-15%. If it is lower or higher than the ratio, the ethanol resistance or transparency will be unqualified.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly transparent ethanol-resistant PMMA material, characterized in that: The invention comprises PMMA resin, PA PACM12 resin, antioxidant and lubricant, wherein the PA PACM12 resin accounts for 5-15% of the total mass of the PMMA resin and the PA PACM12 resin.

2. A highly transparent ethanol-resistant PMMA material according to claim 1, characterized in that: The antioxidant is a phosphite.

3. A highly transparent ethanol-resistant PMMA material according to claim 2, characterized in that: The antioxidant is one of antioxidant 168, antioxidant 626 and antioxidant TPP.

4. The high-transparency ethanol-resistant PMMA material according to claim 2, characterized in that: The amount of the antioxidant used is 0.05%-0.2% of the total mass of the PMMA resin and the PA PACM12 resin.

5. The high-transparency ethanol-resistant PMMA material according to claim 1, characterized in that: The lubricant is an alkyd ester.

6. The high-transparency ethanol-resistant PMMA material according to claim 5, characterized in that: The lubricant is one of lubricant PETS, lubricant TMP and lubricant DEGS.

7. The high-transparency ethanol-resistant PMMA material according to claim 5, characterized in that: The amount of the lubricant used is 0.1%-0.5% of the total mass of the PMMA resin and the PA PACM12 resin.

8. The method for preparing a highly transparent ethanol-resistant PMMA material according to claim 1, characterized in that: The following steps are involved: The PMMA resin, PA PACM12 resin, antioxidant and lubricant are mixed for 5-10 minutes to obtain a uniform mixture; the mixture is added into a twin-screw extruder for melting, extrusion and granulation to obtain a high-transparency ethanol-resistant PMMA material.

9. The method for preparing a highly transparent ethanol-resistant PMMA material according to claim 8, characterized in that: The melt temperatures of each zone of the twin-screw extruder were set to 180±5°C, 260±5°C, 260±5°C, 260±5°C, 250±5°C, 250±5°C, 240±5°C, 250±5°C, 260±5°C; The main engine speed of the twin-screw extruder is 400-500r / min.

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