Heat-resistant high-strength transparent polyamide material as well as preparation method and application thereof

Abstract

The invention provides a heat-resistant high-strength transparent polyamide material as well as a preparation method and application thereof. The preparation method of the heat-resistant high-strength transparent polyamide material comprises the following steps: mixing raw materials including diamine, binary acid, water and a catalyst, heating, and carrying out pre-polycondensation and final polycondensation to obtain the heat-resistant high-strength transparent polyamide material. According to the heat-resistant high-strength transparent polyamide material prepared by the invention, the mechanical strength and thermal performance of the material are improved while high transparency is maintained, the light transmittance is greater than or equal to 90%, the glass transition temperature is greater than or equal to 140 DEG C, the tensile strength is greater than or equal to 55 MPa, transparency can still be maintained at a higher use temperature, and the heat-resistant high-strength transparent polyamide material has relatively good comprehensive performance and is suitable for industrial production. The packaging film can be applied to the fields of aviation industry, automobile manufacturing, electric appliance industry, medical instruments and food packaging.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more specifically, to a heat-resistant, high-strength transparent polyamide material, its preparation method, and its application. Background Technology

[0002] Polyamide is a general-purpose engineering plastic with high mechanical strength, good dimensional stability, and excellent corrosion resistance. Compared to metals, it is lighter and widely used in aerospace, automotive, machinery, electronics, medical devices, and many other fields. However, the strong amide bonds and regular molecular chain arrangement in polyamide result in poor transparency, making it difficult to use in applications requiring high transparency. To meet its specific needs, extensive research has been conducted both domestically and internationally on transparent polyamide materials. Transparent polyamides require light transmittance similar to optical glass, so they are generally amorphous and widely used in transparent components in aerospace, automotive manufacturing, electrical appliance manufacturing, medical devices, and food packaging, requiring good dimensional stability, certain mechanical strength, and heat resistance.

[0003] Currently, there are two main methods for preparing transparent polyamides: chemical and physical methods. The chemical method involves introducing monomers with side chains or cyclic structures into the copolymerization process, disrupting the regularity of the molecular chain and reducing the crystallinity of hydrogen bonding to obtain a transparent amorphous material. However, disrupting the regularity of the molecular chain weakens intermolecular interactions, leading to a decrease in heat resistance and strength. The physical method involves adding additives to form microcrystals, reducing the crystal size to below the visible wavelength, resulting in transparent polyamides containing small spherulites. However, the mechanical strength of the material is often affected.

[0004] As the application fields of transparent polyamide continue to expand, higher requirements are being placed on its mechanical properties and temperature resistance. Therefore, the design and development of heat-resistant and high-strength transparent polyamide materials is of great significance and value in broadening its market applications. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a heat-resistant, high-strength transparent polyamide material, its preparation method, and its application.

[0006] To address the problems existing in current products, this invention introduces benzene ring units into alicyclic monomers to regulate intermolecular interactions, maintaining transparency while improving mechanical strength and heat resistance. After high-temperature polymerization, a heat-resistant and high-strength transparent polyamide material is obtained.

[0007] One of the objectives of this invention is to provide a heat-resistant, high-strength, transparent polyamide material.

[0008] The structural formula of the heat-resistant, high-strength, transparent polyamide material is:

[0009]

[0010] Among them, R1 to R6 are independently selected from hydrogen, C1 to C4 hydrocarbon groups, fluorine or fluorocarbon groups;

[0011] m1 and m2 are each independently selected from integers from 6 to 18;

[0012] n1 and n2 are each independently selected from integers between 15 and 50.

[0013] In a preferred embodiment of the present invention,

[0014] The fluoroalkyl group is a trifluoroalkyl group;

[0015] The C1-C4 hydrocarbon groups are C1-C4 alkyl groups;

[0016] More preferably,

[0017] R1 to R6 are each independently selected from hydrogen, methyl, ethyl, fluorine or trifluoromethyl, more preferably from hydrogen or methyl;

[0018] The m1 and m2 are each independently selected from integers from 8 to 14;

[0019] The n1 and n2 are each independently selected from integers between 20 and 35.

[0020] In a preferred embodiment of the present invention,

[0021] The heat-resistant, high-strength, transparent polyamide material is prepared from raw materials including diamines and diacids.

[0022] The diamine is at least one of the following structural formulas:

[0023]

[0024] Wherein, R1 to R6 are each independently selected from hydrogen, C1 to C4 hydrocarbon groups, fluorine or fluoroalkyl groups; the fluoroalkyl group is preferably trifluoroalkyl; the C1 to C4 hydrocarbon group is preferably C1 to C4 alkyl; more preferably, R1 to R6 are each independently selected from hydrogen, methyl, ethyl, fluorine or trifluoromethyl, and most preferably selected from hydrogen or methyl;

[0025] The dicarboxylic acid is a straight-chain dicarboxylic acid with 8 to 20 carbon atoms, preferably a straight-chain dicarboxylic acid with 10 to 16 carbon atoms.

[0026] In the embodiments, formula (Ⅲ) is a diamine 1 # Formula (Ⅳ) is a diamine 2 # .

[0027] In a preferred embodiment of the present invention,

[0028] The light transmittance of the heat-resistant, high-strength, transparent polyamide material is ≥90%;

[0029] The glass transition temperature of the heat-resistant, high-strength, transparent polyamide material is ≥140℃;

[0030] The heat-resistant, high-strength transparent polyamide material has a tensile strength ≥55MPa.

[0031] The second objective of this invention is to provide a method for preparing a heat-resistant, high-strength, transparent polyamide material, comprising:

[0032] After mixing raw materials including diamine, diacid, water, and catalyst, the mixture is heated to carry out pre-condensation and final condensation reactions to obtain the heat-resistant, high-strength, transparent polyamide material; preferably, the raw materials also include antioxidants.

[0033] The diamine and diacid mentioned above are the aforementioned diamine and diacid.

[0034] In a preferred embodiment of the present invention,

[0035] The water is pure water, preferably deoxygenated by bubbling with nitrogen or argon gas.

[0036] The catalyst is at least one of sodium hypophosphite, sodium phosphate, and phosphoric acid; preferably sodium hypophosphite.

[0037] The antioxidant is at least one of antioxidant 1098, antioxidant 1010, antioxidant 1178, and antioxidant H10, preferably antioxidant 1010.

[0038] In a preferred embodiment of the present invention,

[0039] The molar ratio of the diamine to the diacid is (1.00–1.02):1, preferably (1.005–1.01):1;

[0040] The amount of water used is 10-80% of the total mass of the diamine and diacid, preferably 25-50%;

[0041] The amount of catalyst used is 0.05-0.5% of the total mass of the diamine and diacid, preferably 0.1-0.3%;

[0042] The amount of the antioxidant is 0.1 to 1.0% of the total mass of the diamine and diacid, preferably 0.3 to 0.6%.

[0043] In a preferred embodiment of the present invention,

[0044] The pre-condensation and final condensation reactions are carried out under a protective gas atmosphere, wherein the protective gas is at least one of nitrogen, an inert gas, and carbon dioxide; the inert gas is preferably argon; this can be achieved by purging the protective gas under vacuum before the reaction.

[0045] After the reaction, the material is discharged, drawn into fibers, and granulated.

[0046] In a preferred embodiment of the present invention,

[0047] The reaction temperature for the pre-polymerization is 200–240°C, preferably 210–230°C;

[0048] The reaction time for the pre-condensation polymerization is 3 to 8 hours, preferably 4 to 6 hours;

[0049] The final polycondensation reaction temperature is 260–290°C, preferably 270–280°C;

[0050] The reaction time for the final polycondensation is 0.5 to 3 hours, preferably 1 to 2 hours;

[0051] The vacuum degree of the final polycondensation reaction is 0.2 to 0.8 atm, preferably 0.4 to 0.6 atm.

[0052] The third objective of this invention is to provide a heat-resistant, high-strength, transparent polyamide material obtained by the above preparation method.

[0053] The fourth objective of this invention is to provide an application of a high-strength transparent polyamide material in the fields of aerospace, automobile manufacturing, electrical appliance industry, medical devices, and food packaging.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0055] This invention prepares polyamide materials by introducing a new structural monomer. The diamine used in this invention introduces a benzene ring structure on the basis of an alicyclic structure, which improves the heat resistance and mechanical properties of the polyamide material while maintaining light transmittance, and can adapt to more demanding application scenarios.

[0056] The heat-resistant, high-strength, transparent polyamide material prepared by this invention improves the mechanical strength and thermal properties of the material while maintaining high transparency. It has a light transmittance of ≥90%, a glass transition temperature of ≥140℃, and a tensile strength of ≥55MPa. It can maintain transparency even at higher operating temperatures and has good comprehensive performance. Detailed Implementation

[0057] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0058] It should also be noted that the various specific technical features described in the following embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the various possible combinations will not be described separately in this invention.

[0059] Furthermore, various embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention. The resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0060] Reagent source: All reagents are commercially available.

[0061] In the examples, the diamine was purchased from Chongqing Futeng Pharmaceutical Co., Ltd., the diamine in the comparative example was purchased from Shanghai Yanze Chemical Co., Ltd., and the dicarboxylic acid was purchased from Kaisai Biotechnology Co., Ltd.

[0062] Test method:

[0063] Relative molecular mass: determined using gel permeation chromatography (GPC). The sample was dissolved in hexafluoroisopropanol at a concentration of 0.1 g / mL, filtered through a 0.2 μm filter membrane before injection, and the mobile phase was hexafluoroisopropanol at a flow rate of 0.5 mL / min and a column temperature of 35 °C.

[0064] Light transmittance: ASTM D1003

[0065] Tensile strength: GB / T 1040.1-2006 / ISO 527-1:1993

[0066] Glass transition temperature: The sample was tested using a differential scanning calorimeter. 5-10 mg of sample was weighed and placed in a sample pan under nitrogen atmosphere protection.

[0067] Example 1

[0068] Polyamide preparation: (1) 272.4g of diamine of formula (III) 1 #(R1=H, R2=H, CAS No.: 34668-21-8), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1:1), 150.8g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃ and control the vacuum degree to 0.6atm. After reacting for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0069] Diamine 1 # The structural formula is:

[0070]

[0071] The structural formula of the obtained polyamide product is:

[0072]

[0073] Where R1 = H, R2 = H, m1 = 10, and n1 is 23.

[0074] Example 2

[0075] Polyamide preparation: (1) 273.8g of diamine of formula (III) 1 # (R1=H, R2=H, CAS No.: 34668-21-8), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.005:1), 151.2g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃ and control the vacuum degree to 0.6atm. After reacting for 1.0h, stop stirring, open the discharge valve, and fill with argon. The material flows out through the injection head, cools and is granulated to prepare polyamide products.

[0076] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=10, and n1 is 25.

[0077] Example 3

[0078] Preparation of polyamide: (1) 275.2g of diamine of formula (III)# (R1=H, R2=H, CAS No.: 34668-21-8), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 151.6g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃ and control the vacuum degree to 0.6atm. After reacting for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0079] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=10, and n1 is 28.

[0080] Example 4

[0081] Preparation of polyamide: (1) 277.9g of diamine of formula (III) # (R1=H, R2=H, CAS No.: 34668-21-8), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.02:1), 152.4g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃, control the vacuum degree to 0.6atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0082] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=10, and n1 is 24.

[0083] Example 5

[0084] Preparation of polyamide: (1) 275.2g of diamine of formula (III) #(R1=H, R2=H, CAS No.: 34668-21-8), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 151.6g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to raise the temperature to 220℃ and the pressure inside the reactor is raised to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Raise the temperature to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0085] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=10, and n1 is 30.

[0086] Example 6

[0087] Polyamide preparation: (1) 273.8g of diamine of formula (III) 1 # (R1=H, R2=H, CAS No.: 34668-21-8), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.005:1), 159.6g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃, control the vacuum degree to 0.6atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0088] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=12, and n1 is 25.

[0089] Example 7

[0090] Preparation of polyamide: (1) 275.2g of diamine of formula (III) #(R1=H, R2=H, CAS No.: 34668-21-8), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 160.0g water, 0.5g sodium hypophosphite catalyst and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃ and control the vacuum degree to 0.4atm. After reacting for 1.0h, stop stirring, open the discharge valve, and fill with argon. The material flows out through the injection head, cools and is granulated to prepare polyamide products.

[0091] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=12, and n1 is 29.

[0092] Example 8

[0093] Preparation of polyamide: (1) 275.2g of diamine of formula (III) # (R1=H, R2=H, CAS No.: 34668-21-8), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 160.0g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to raise the temperature to 210℃ and the pressure inside the reactor is raised to 2.2MPa. Maintain this temperature and pressure for 3.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 3.0h. (4) Raise the temperature to 280℃, control the vacuum degree to 0.6atm, react for 2.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0094] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=12, and n1 is 33.

[0095] Example 9

[0096] Preparation of polyamide: (1) 275.2g of diamine of formula (III) #(R1=H, R2=H, CAS No.: 34668-21-8), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 160.0g water, 0.5g catalyst sodium phosphate and 1.5g antioxidant 1098 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The air is replaced with argon gas three times under vacuum. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon gas, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0097] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=12, and n1 is 29.

[0098] Example 10

[0099] Preparation of polyamide: (1) 275.2g of diamine of formula (III) # (R1=H, R2=H, CAS No.: 34668-21-8), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 533.6g water, 1.6g catalyst sodium hypophosphite and 3.2g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to raise the temperature to 220℃ and the pressure inside the reactor is raised to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Raise the temperature to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0100] The structural formula of the obtained polyamide product is shown in formula (Ⅰ), where R1=H, R2=H, m1=12, and n1 is 29.

[0101] Example 11

[0102] Preparation of polyamide: (1) 275.2g of diamine of formula (Ⅳ) #(R3~R6=H, CAS No.: 2376729-25-6), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 151.6g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to 220℃ and the pressure inside the reactor is increased to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Heat to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0103] Diamine 2 # The structural formula is:

[0104]

[0105] The structural formula of the obtained polyamide product is:

[0106]

[0107] Where R3~R6=H, m2=10, and n2 is 30.

[0108] Example 12

[0109] Preparation of polyamide: (1) 275.2g of diamine of formula (Ⅳ) # (R3~R6=H, CAS No.: 2376729-25-6), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 160.0g water, 0.5g catalyst sodium hypophosphite and 1.5g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times. (2) Heat for 1.0h to raise the temperature to 220℃ and the pressure inside the reactor is raised to 2.2MPa. Maintain this temperature and pressure for 2.0h. (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h. (4) Raise the temperature to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0110] The structural formula of the obtained polyamide product is shown in formula (Ⅱ), where R3~R6=H, m2=12, and n2 is 29.

[0111] Comparative Example 1

[0112] Polyamide preparation: (1) 212.5g of diamine ( CAS No.: 1761-71-3), 230.3g dodecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 132.8g water, 0.4g catalyst sodium hypophosphite and 1.3g antioxidant 1010 are mixed evenly and then added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times; (2) Heat for 1.0h to raise the temperature to 220℃ and the pressure inside the reactor is raised to 2.2MPa. Maintain this temperature and pressure for 2.0h; (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h; (4) Raise the temperature to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0113] Comparative Example 2

[0114] Polyamide preparation: (1) 212.5g of diamine ( CAS No.: 1761-71-3), 258.4g tetradecanoic acid (molar ratio of diamine to dicarboxylic acid = 1.01:1), 141.3g water, 0.5g catalyst sodium hypophosphite and 1.4g antioxidant 1010 are mixed evenly and added to a 2.0L high temperature and high pressure polymerization reactor. The reactor is evacuated and the air is replaced with argon three times; (2) Heat for 1.0h to raise the temperature to 220℃ and the pressure inside the reactor is raised to 2.2MPa. Maintain this temperature and pressure for 2.0h; (3) Slowly release water vapor and reduce the pressure inside the reactor to normal pressure within 2.0h; (4) Raise the temperature to 270℃, control the vacuum degree to 0.4atm, react for 1.0h, stop stirring, open the discharge valve, fill with argon, and the material flows out through the injection head. After cooling, it is granulated to prepare polyamide products.

[0115] Table 1 Properties of Polyamide Materials

[0116]

[0117] As shown in Table 1:

[0118] Compared with Comparative Example 1, Example 5 prepared a heat-resistant and high-strength transparent polyamide material with a higher molecular weight. With a light transmittance of 90%, the tensile strength increased by 13% and the glass transition temperature increased by 17°C. This proves that Example 5 introduced a benzene ring structure on the basis of the alicyclic structure of Comparative Example 1, which improved the heat resistance and mechanical properties of the polyamide material while maintaining transparency.

[0119] Compared with Comparative Example 2, Example 7 prepared a heat-resistant and high-strength transparent polyamide material with a higher molecular weight. With a light transmittance of 90%, the tensile strength increased by 17% and the glass transition temperature increased by 16°C. This proves that Example 7 introduced a benzene ring structure on the basis of the alicyclic structure of Comparative Example 2, which improved the heat resistance and mechanical properties of the polyamide material while maintaining transparency.

[0120] The heat-resistant and high-strength transparent polyamide materials prepared in Examples 1-12 maintain high transparency while improving the mechanical strength and thermal properties of the material. The light transmittance is ≥90%, the glass transition temperature is ≥140℃, and the tensile strength is ≥55MPa. They can maintain transparency even at higher operating temperatures and have good comprehensive performance.

[0121] The preparation method of this invention is simple and controllable in the experimental process, and can meet the high performance requirements of different application scenarios.

Claims

1. A heat-resistant, high-strength, transparent polyamide material, with the following structural formula: in, R1 to R6 are each independently selected from hydrogen, C1 to C4 hydrocarbon groups, fluorine or fluoroalkyl groups; m1 and m2 are each independently selected from integers from 6 to 18; n1 and n2 are each independently selected from integers between 15 and 50.

2. The heat-resistant, high-strength, transparent polyamide material as described in claim 1, characterized in that: The fluoroalkyl group is a trifluoroalkyl group; and / or, The C1-C4 hydrocarbon groups are C1-C4 alkyl groups; More preferably, R1 to R6 are each independently selected from hydrogen, methyl, ethyl, fluorine, or trifluoromethyl, more preferably from hydrogen or methyl; and / or, The m1 and m2 are each independently selected from integers from 8 to 14; and / or, The n1 and n2 are each independently selected from integers between 20 and 35.

3. The heat-resistant, high-strength, transparent polyamide material as described in claim 1, characterized in that: The heat-resistant, high-strength, transparent polyamide material is prepared from raw materials including diamines and diacids. The diamine is at least one of the following structural formulas: Wherein, R1 to R6 are each independently selected from hydrogen, C1 to C4 hydrocarbon groups, fluorine, or fluoroalkyl groups; the fluoroalkyl group is preferably trifluoroalkyl; the C1 to C4 hydrocarbon group is preferably C1 to C4 alkyl; more preferably, R1 to R6 are each independently selected from hydrogen, methyl, ethyl, fluorine, or trifluoromethyl, most preferably from hydrogen or methyl; and / or, The dicarboxylic acid is a straight-chain dicarboxylic acid with 8 to 20 carbon atoms, preferably a straight-chain dicarboxylic acid with 10 to 16 carbon atoms.

4. The heat-resistant, high-strength, transparent polyamide material according to any one of claims 1 to 3, characterized in that: The light transmittance of the heat-resistant, high-strength, transparent polyamide material is ≥90%; and / or, The glass transition temperature of the heat-resistant, high-strength, transparent polyamide material is ≥140℃; and / or, The heat-resistant, high-strength transparent polyamide material has a tensile strength ≥55MPa.

5. A method for preparing a heat-resistant, high-strength, transparent polyamide material as described in any one of claims 1 to 4, comprising: After mixing raw materials including diamine, diacid, water, and catalyst, the mixture is heated to carry out pre-condensation and final condensation reactions to obtain the heat-resistant, high-strength, transparent polyamide material; preferably, the raw materials also include antioxidants. The diamine and dicarboxylic acid are those described in claim 3.

6. The method for preparing the heat-resistant, high-strength, transparent polyamide material as described in claim 5, characterized in that: The water is pure water, preferably treated with nitrogen or argon bubbling to remove oxygen; and / or, The catalyst is at least one of sodium hypophosphite, sodium phosphate, and phosphoric acid; and / or, The antioxidant is at least one of antioxidant 1098, antioxidant 1010, antioxidant 1178, and antioxidant H10.

7. The method for preparing the heat-resistant, high-strength, transparent polyamide material as described in claim 5, characterized in that: The molar ratio of the diamine to the diacid is (1.00–1.02):1, preferably (1.005–1.01):1; and / or, The amount of water used is 10-80% of the total mass of the diamine and diacid, preferably 25-50%; and / or, The catalyst is used in an amount of 0.05-0.5% of the total mass of the diamine and diacid, preferably 0.1-0.3%; and / or, The amount of the antioxidant is 0.1 to 1.0% of the total mass of the diamine and diacid, preferably 0.3 to 0.6%.

8. The method for preparing the heat-resistant, high-strength, transparent polyamide material as described in claim 5, characterized in that: The pre-condensation and final condensation reactions are carried out under a protective gas atmosphere, wherein the protective gas is at least one selected from nitrogen, an inert gas, and carbon dioxide; the inert gas is preferably argon; and / or, After reaction, the discharged material is drawn into fibers and granulated; and / or, The reaction temperature for the prepolymerization is 200–240°C, preferably 210–230°C; and / or, The reaction time for the prepolymerization is 3–8 hours, preferably 4–6 hours; and / or, The final polycondensation reaction temperature is 260–290°C, preferably 270–280°C; and / or, The final polycondensation reaction time is 0.5–3 h, preferably 1–2 h; and / or, The vacuum degree of the final polycondensation reaction is 0.2 to 0.8 atm, preferably 0.4 to 0.6 atm.

9. A heat-resistant, high-strength, transparent polyamide material obtained by the preparation method according to any one of claims 5 to 8.

10. The application of a heat-resistant, high-strength, transparent polyamide material as described in any one of claims 1 to 4, 9 in the fields of aerospace industry, automobile manufacturing, electrical appliance industry, medical device, and food packaging.

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