A highly transparent ethanol-resistant PMMA material and its preparation method

Abstract

This invention discloses a highly transparent ethanol-resistant PMMA material and its preparation method, belonging to the field of polymer material modification technology. It comprises PMMA resin, PA PACM12 resin, antioxidant, and lubricant. The highly transparent ethanol-resistant PMMA material is obtained by mixing the components and adding them to a twin-screw extruder, followed by melting, extrusion, and granulation. By embedding microcrystalline PACM12 groups into the PMMA through blending modification, ethanol can be effectively prevented from attacking the PMMA matrix, thus avoiding damage from high concentrations of ethanol, while the addition does not affect the transparency of the PMMA material. This invention solves the problems of ethanol intolerance, fogging, and cracking in transparent housing materials for automotive taillights, and can also be used for optical applications.

Description

Technical Field

[0001] This invention belongs to the field of polymer material modification technology, specifically relating to a highly transparent ethanol-resistant PMMA material and its preparation method. Background Technology

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

[0003] There are two common solutions to improve the ethanol resistance of automotive taillight covers: one is to coat the surface of the parts with a corrosion-resistant coating. This solution increases the number of processes, reduces the yield rate, and increases costs. The other solution is to introduce a five- or six-membered ring structure during the PMMA polymerization process to avoid the PMMA material from swelling and cracking in the ethanol environment. This solution has high material viscosity, is difficult to process, and is prone to yellowing at high temperatures. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a highly transparent ethanol-resistant PMMA material, which has excellent ethanol resistance and high transparency.

[0005] Another objective of this invention is to provide a method for preparing a highly transparent ethanol-resistant PMMA material. This method is simple in process, easy to operate and control, and suitable for large-scale industrial production.

[0006] The objective of this 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 PA PACM12 resin.

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

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

[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 antioxidant used is 0.05%-0.2% of the total mass of PMMA resin and PA PACM12 resin.

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

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

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

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

[0017] PMMA resin, PA PACM12 resin, antioxidant, and lubricant are mixed for 5-10 minutes to obtain a homogeneous mixture. The mixture is then added to a twin-screw extruder for melting, extrusion, and granulation to obtain a highly transparent ethanol-resistant PMMA material.

[0018] Furthermore, the melt temperatures of each zone of the twin-screw extruder are set to 180±5℃, 260±5℃, 260±5℃, 260±5℃, 250±5℃, 250±5℃, 250±5℃, 240±5℃, 250±5℃, and 260±5℃.

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

[0020] The beneficial effects of this invention are:

[0021] This invention uses co-extrusion to uniformly disperse PA PACM12 resin in PMMA resin. Each repeating unit of the molecular chain in PA PACM12 resin has two alicyclic rings, resulting in greater rigidity of the molecular chain, greater steric hindrance to the spatial movement of chain segments, and difficulty in chain segment movement. Compared with traditional PA materials, it is more difficult to crystallize, and only microcrystals can be formed in the system. This microcrystalline phase can not only effectively prevent ethanol from attacking the PMMA matrix, but also, since these microcrystals are nanoscale, they do not affect the transmittance of visible light and do not affect the transparency of the material. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort 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, manufactured by Wanhua Company, HD01A;

[0025] PA PACM12 resin, manufactured by Evonik.

[0026] PA 12 resin, manufactured by Evonik.

[0027] Antioxidant 168, manufactured by BASF in Germany;

[0028] PETS lubricant, manufactured by Shanghai Langzhen.

[0029] The preparation methods of the highly transparent ethanol-resistant PMMA materials in the following examples and comparative examples are 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 to a twin-screw extruder for melting, extrusion and granulation to obtain a highly transparent ethanol-resistant PMMA material;

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

[0032] The melt temperatures of each zone of the twin-screw extruder are set to 185℃, 265℃, 265℃, 265℃, 255℃, 255℃, 255℃, 245℃, 255℃, and 265℃.

[0033] The main unit's rotation speed is 500 r / min;

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

[0035] Table 1

[0036]

[0037] The PMMA materials obtained in Examples 1-3 and Comparative Examples 1-4 were first dried in an 85°C oven for 3 hours to fully remove moisture. Then, they were injection molded into strips and templates using an injection molding machine. After conditioning under standard conditions for 24 hours, performance testing was conducted. The testing standards and conditions are as follows:

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

[0039] Tensile strength test: conducted according to ISO 527-2:2012 standard, with a specimen size of 135*10*4mm and a tensile speed of 50mm / min;

[0040] Bending strength and bending modulus tests: conducted according to ISO 178:2019 standard, with specimen size of 80*10*4mm, bending speed of 2mm / min, and span of 64mm;

[0041] Notched impact strength test of simply supported beam: conducted according to ISO 179-1:2023 standard, with a specimen size of 80*10*4mm, A-type notch, and 4J pendulum;

[0042] Transparency test: A 3mm standard sample was tested in the visible light band (380nm-780nm) using a Palmer 1050+ UV-Vis spectrophotometer; a transparency of ≥90% was considered acceptable.

[0043] Ethanol resistance test: Standard environment (temperature: 25℃, humidity: 60%RH); Test materials: Test fixture dimensions (radius R = 198mm), test specimen (ISO 527 / 1A tensile specimen, length 170mm), 90% ethanol solvent (ethanol / water 90:10v / v); After applying stress, the ethanol resistance is determined by the time of fracture, ≥1min is considered qualified;

[0044] Materials can only be considered qualified if both transparency and ethanol resistance are up to standard.

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

[0046] Table 2

[0047]

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

[0049] Compared with Comparative Example 1 and Examples 1-3, the PMMA material prepared without adding PA PACM12 resin has poor ethanol resistance. The reason is that each repeating unit of the molecular chain in PA PACM12 resin has two alicyclic rings, resulting in greater rigidity of the molecular chain, greater steric hindrance to the spatial movement of chain segments, and difficulty in chain segment movement. Compared with traditional PA materials, it is more difficult to crystallize, and only microcrystals can be formed in the system. This microcrystalline phase can not only effectively prevent ethanol from attacking the PMMA matrix, but also, since this microcrystal is nanoscale, it does not affect the transmittance of visible light and does not affect the transparency of the PMMA material.

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

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

[0052] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0053] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A highly transparent, ethanol-resistant PMMA material, characterized in that, It includes PMMA resin, PA PACM12 resin, antioxidants and lubricants, wherein the PA PACM12 resin accounts for 5-15% of the total mass of PMMA resin and PA PACM12 resin.

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

3. The highly transparent, ethanol-resistant PMMA material according to claim 1, characterized in that, The antioxidant is one of antioxidant 168, antioxidant 626, and antioxidant TPP.

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

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

6. The highly transparent, ethanol-resistant PMMA material according to claim 1, characterized in that, The lubricant is one of the following: PETS, TMP, and DEGS.

7. The highly transparent, 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 PMMA resin and PA PACM12 resin.

8. The method for preparing a highly transparent, ethanol-resistant PMMA material according to claim 1, characterized in that, Includes the following steps: PMMA resin, PA PACM12 resin, antioxidant, and lubricant are mixed for 5-10 minutes to obtain a homogeneous mixture. The mixture is then added to a twin-screw extruder for melting, extrusion, and granulation to obtain a highly transparent 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 are set to 180±5℃, 260±5℃, 260±5℃, 260±5℃, 250±5℃, 250±5℃, 250±5℃, 240±5℃, 250±5℃, and 260±5℃. The main motor speed of the twin-screw extruder is 400-500 r / min.

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