A bio-based nylon thermal insulation material resistant to heat and oxygen aging and a preparation method thereof

Abstract

The invention relates to the technical field of nylon materials, and discloses a bio-based nylon thermal insulation material resistant to heat and oxygen aging and a preparation method thereof. The bio-based nylon thermal insulation material resistant to heat and oxygen aging of the invention comprises the following raw materials in parts by weight: 45-55 parts of bio-based nylon material, 5-8 parts of glass fiber, 8-12 parts of toughening agent, 3-6 parts of functionalized silicone, 0.02-0.05 parts of antioxidant, 1-2 parts of lubricant, and 0.5-2 parts of coupling agent; the material is made by taking bio-based nylon as the main matrix, adding glass fiber, toughening agent, functionalized silicone, antioxidant and other functional additives, and then extruding the mixture, wherein the functionalized silicone can synergize with the antioxidant to improve the heat and oxygen aging resistance of the matrix.

Description

Technical Field

[0001] The invention relates to the technical field of nylon materials, and in particular to a bio-based nylon thermal insulation material resistant to heat and oxygen aging and a preparation method thereof. Background Art

[0002] As a renewable resource material, bio-based nylon has good mechanical properties, chemical resistance and low thermal conductivity. It is gradually replacing traditional petroleum-based nylon and is an ideal thermal insulation material with broad application prospects in the fields of construction, automobiles, aerospace, etc. However, in practical applications, bio-based nylon materials face the problem of thermal oxidative aging, especially in high temperature and oxygen environments. They are easily affected by thermal oxidative aging, which leads to the decomposition of the material's molecular chain, deterioration of mechanical properties, and a significant decrease in thermal stability, limiting their wide application in the field of thermal insulation.

[0003] In order to improve the thermal oxidation aging resistance of bio-based nylon, researchers have modified it through various methods. For example, adding antioxidants (such as hindered phenols, hindered amines and benzophenones) or antioxidants can effectively inhibit the thermal oxidation aging reaction. However, traditional antioxidants or antioxidants have a small molecular weight, are easy to precipitate and migrate in nylon materials, and have limited thermal oxidation aging resistance. Therefore, it is necessary to develop an additive with a relatively large molecular weight, not easy to precipitate and with excellent thermal oxidation aging resistance to meet practical application needs. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a bio-based nylon thermal insulation material resistant to heat and oxygen aging and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A bio-based nylon thermal insulation material resistant to heat and oxygen aging, comprising the following raw materials in parts by weight: 45-55 parts of bio-based nylon material, 5-8 parts of glass fiber, 8-12 parts of toughening agent, 3-6 parts of functionalized silicone, 0.02-0.05 parts of antioxidant, 1-2 parts of lubricant, and 0.5-2 parts of coupling agent;

[0007] The bio-based nylon material is one of PA610 nylon material, PA56 nylon material and PA1010 nylon material;

[0008] The toughening agent is selected from one of SEBS or maleic anhydride grafted POE;

[0009] The antioxidant is a phosphite antioxidant, preferably selected from antioxidant 168;

[0010] The lubricant is one of zinc stearate or calcium stearate;

[0011] The coupling agent is a silane coupling agent, preferably, selected from one of KH550, KH560 or KH570;

[0012] The functionalized silicone is prepared by the following steps:

[0013] Step A1, 4-(phenylamino)benzaldehyde, p-aminophenol and toluene are mixed, condensed and refluxed for 4-6 hours under nitrogen and 115° C., transferred to benzene and allowed to stand for 10 minutes, filtered, washed and dried to obtain a terminal hydroxy diphenylamine derivative;

[0014] Further, in step A1, the molar ratio of 4-(phenylamino)benzaldehyde to p-aminophenol is 1:1;

[0015] Step A2, adding ethylenediaminetetraacetic acid, p-toluenesulfonic acid and DMF (N,N-dimethylformamide) to the terminal hydroxyl diphenylamine derivative, mixing, heating to 120-140° C., stirring for 6 hours, rotary evaporation and drying to obtain a carboxylated diphenylamine derivative;

[0016] Furthermore, in step A2, the molar ratio of ethylenediaminetetraacetic acid to the terminal hydroxy diphenylamine derivative is 1:1-2, and p-toluenesulfonic acid is 0.5%-1.5% of the mass of the terminal hydroxy diphenylamine derivative;

[0017] Step A3, adding allylamine and DMF to the carboxylated diphenylamine derivative, mixing, and heating to 160-170° C. and reflux for 4-6 hours under nitrogen, cooling to 40° C., adding 0.01-0.05 mol / L manganese nitrate solution, adjusting the pH to 8, stirring the reaction for 2-3 hours, and distilling under reduced pressure to obtain a functionalized diphenylamine derivative;

[0018] Further, in step A3, the mass ratio of the carboxylated diphenylamine derivative, allylamine and manganese nitrate solution is 0.1 mol: 0.1 mol: 10 mL;

[0019] Step A4, methyl orthosilicate and ethanol aqueous solution are mixed, stirred for 30 minutes under nitrogen and ice-water bath, dimethylchlorosilane is added, stirred for 3 hours, concentrated sulfuric acid is added dropwise and stirred for 20 minutes, the organosilicon layer is separated and collected, washed, extracted and dried to obtain hydrogen-containing organosilicon;

[0020] Further, in step A4, the usage ratio of methyl orthosilicate, dimethylchlorosilane and concentrated sulfuric acid is 0.04 mol: 0.18-0.2 mol: 0.2-0.3 mL;

[0021] Further, the volume ratio of ethanol to water in the ethanol solution in step A4 is 7:3;

[0022] Step A5, mixing the functionalized diphenylamine derivative, toluene and chloroplatinic acid isopropanol solution, adding hydrogenated organosilicon under nitrogen at 80° C., stirring for 2-3 hours, then adding isocyanoethyl methacrylate and continuing the reaction for 2-3 hours, filtering and drying to obtain the functionalized organosilicon;

[0023] Further, in step A5, the amount ratio of the functionalized diphenylamine derivative, hydrogen-containing organosilicon, isocyanoethyl methacrylate and chloroplatinic acid isopropanol solution is 0.2-0.4 mol: 0.1 mol: 0.2-0.4 mol: 10 mL;

[0024] Furthermore, the chloroplatinic acid isopropanol solution in step A5 is prepared by mixing chloroplatinic acid and isopropanol in a ratio of 0.05-0.07 g:10 mL.

[0025] A method for preparing a bio-based nylon thermal insulation material resistant to heat and oxygen aging, comprising the following steps:

[0026] The raw materials are weighed by weight, and the bio-based nylon material, glass fiber, toughening agent, functional silicone, antioxidant, lubricant and coupling agent are mixed, and then put into a twin-screw extruder, and extruded, cooled, dried and pelletized at 210-230° C. to obtain a bio-based nylon thermal insulation material resistant to heat and oxygen aging.

[0027] Beneficial effects of the present invention:

[0028] The heat-oxidative aging-resistant bio-based nylon thermal insulation material of the present invention is prepared by using bio-based nylon as a main matrix, adding glass fiber, toughening agent, functionalized silicone, antioxidant and other functional additives and then mixing and extruding. Among them, the functionalized silicone can work synergistically with the antioxidant to improve the heat-oxidative aging resistance of the matrix.

[0029] The introduction of functionalized silicone can significantly improve the heat-oxidative aging resistance of the matrix. This is because the functionalized silicone contains diphenylamine structure, manganese complex and Si-O bond, and the synergistic effect of the three gives the matrix excellent heat-oxidative aging resistance. Among them, the diphenylamine structure plays the role of the main antioxidant in the matrix, using the active H atoms it contains to capture free radicals, prevent the cross-linking reaction, inhibit the production of small molecules, reduce the oxidation and breakage of nylon molecules by free radicals, and prevent the aging of the matrix. The manganese complex can release manganese ions under certain conditions. When the nylon matrix ages, hydroperoxides will be produced, which will further oxidize the matrix. Antioxidants (phosphites) can decompose hydroperoxides, and manganese ions can promote the decomposition of hydroperoxides, further reducing the content of hydroperoxides in the matrix. In addition, the isocyanate group contained in the functionalized silicone can also react with the terminal carboxyl or amino group of the nylon molecular chain, thereby introducing Si-O bonds with high bond energy into the nylon molecular chain, further improving the heat-oxidative aging resistance of the matrix. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0031] Example 1: Functionalized silicone is prepared by the following steps:

[0032] Step A1, 0.1 mol 4-(phenylamino)benzaldehyde, 0.1 mol p-aminophenol and 100 mL toluene were mixed, condensed and refluxed for 4 h under nitrogen at 115° C., transferred to 100 mL benzene and allowed to stand for 10 min, filtered, washed and dried to obtain a terminal hydroxy diphenylamine derivative;

[0033] Step A2, add 0.1 mol of ethylenediaminetetraacetic acid, p-toluenesulfonic acid and 100 mL of DMF to 0.1 mol of terminal hydroxy diphenylamine derivative, mix, heat to 120° C., stir for 6 h, rotary evaporate and dry to obtain a carboxylated diphenylamine derivative, wherein the p-toluenesulfonic acid is 0.5% of the mass of the terminal hydroxy diphenylamine derivative;

[0034] Step A3, add 0.1 mol of allylamine and 100 mL of DMF to 0.1 mol of the carboxylated diphenylamine derivative, mix, and heat to 160° C. and reflux for 4 h under nitrogen, cool to 40° C., add 10 mL of 0.01 mol / L manganese nitrate solution, adjust the pH to 8, stir to react for 2 h, and distill under reduced pressure to obtain a functionalized diphenylamine derivative;

[0035] Step A4, 0.04 mol of methyl orthosilicate and 100 mL of ethanol aqueous solution were mixed, stirred for 30 min under nitrogen and ice-water bath, and then 0.18 mol of dimethylchlorosilane was added, stirred for 3 h, 0.2 mL of concentrated sulfuric acid was added dropwise and stirred for 20 min, and the organosilicon layer was separated and collected, washed, extracted and dried to obtain hydrogenated organosilicon, wherein the volume ratio of ethanol to water in the ethanol solution was 7:3;

[0036] Step A5, mix 0.2 mol of functionalized diphenylamine derivative, 200 mL of toluene and 10 mL of chloroplatinic acid isopropanol solution, add 0.1 mol of hydrogenated organosilicon under nitrogen at 80°C, stir and react for 2 h, then add 0.3 mol of isocyanoethyl methacrylate and continue to react for 2 h, filter and dry to obtain functionalized organosilicon. The chloroplatinic acid isopropanol solution is prepared by mixing chloroplatinic acid and isopropanol in a ratio of 0.05 g:10 mL.

[0037] Example 2: Functionalized silicone is prepared by the following steps:

[0038] Step A1, 0.1 mol 4-(phenylamino)benzaldehyde, 0.1 mol p-aminophenol and 100 mL toluene were mixed, condensed and refluxed for 5 h under nitrogen at 115° C., transferred to 100 mL benzene and allowed to stand for 10 min, filtered, washed and dried to obtain a terminal hydroxy diphenylamine derivative;

[0039] Step A2, add 0.1 mol of ethylenediaminetetraacetic acid, p-toluenesulfonic acid and 100 mL of DMF to 0.1 mol of terminal hydroxy diphenylamine derivative, mix, heat to 130°C, stir for 6 hours, rotary evaporate and dry to obtain a carboxylated diphenylamine derivative, wherein p-toluenesulfonic acid is 1% of the mass of the terminal hydroxy diphenylamine derivative;

[0040] Step A3, add 0.1 mol of allylamine and 100 mL of DMF to 0.1 mol of the carboxylated diphenylamine derivative, mix, and heat to 165° C. and reflux for 5 h under nitrogen, cool to 40° C., add 10 mL of 0.03 mol / L manganese nitrate solution, adjust the pH to 8, stir to react for 2.5 h, and distill under reduced pressure to obtain a functionalized diphenylamine derivative;

[0041] Step A4, 0.04 mol of methyl orthosilicate and 100 mL of ethanol aqueous solution were mixed, stirred for 30 min under nitrogen and ice-water bath, and then 0.19 mol of dimethylchlorosilane was added, stirred for 3 h, 0.25 mL of concentrated sulfuric acid was added dropwise and stirred for 20 min, and the organosilicon layer was separated and collected, washed, extracted and dried to obtain hydrogenated organosilicon, wherein the volume ratio of ethanol to water in the ethanol solution was 7:3;

[0042] Step A5, 0.3 mol of functionalized diphenylamine derivative, 200 mL of toluene and 10 mL of chloroplatinic acid isopropanol solution were mixed, and 0.1 mol of hydrogen-containing organosilicon was added under nitrogen at 80°C, and the reaction was stirred for 2.5 h, and then 0.2 mol of isocyanoethyl methacrylate was added to continue the reaction for 2.5 h, filtered and dried to obtain functionalized organosilicon. The chloroplatinic acid isopropanol solution was prepared by mixing chloroplatinic acid and isopropanol in a ratio of 0.06 g:10 mL.

[0043] Example 3: Functionalized silicone is prepared by the following steps:

[0044] Step A1, 0.1 mol 4-(phenylamino)benzaldehyde, 0.1 mol p-aminophenol and 100 mL toluene were mixed, condensed and refluxed for 6 h under nitrogen at 115° C., transferred to 100 mL benzene and allowed to stand for 10 min, filtered, washed and dried to obtain a terminal hydroxy diphenylamine derivative;

[0045] Step A2, add 0.1 mol of ethylenediaminetetraacetic acid, p-toluenesulfonic acid and 100 mL of DMF to 0.1 mol of terminal hydroxy diphenylamine derivative, mix, heat to 140°C, stir for 6 hours, rotary evaporate and dry to obtain a carboxylated diphenylamine derivative, wherein the p-toluenesulfonic acid is 1.5% of the mass of the terminal hydroxy diphenylamine derivative;

[0046] Step A3, add 0.1 mol of allylamine and 100 mL of DMF to 0.1 mol of the carboxylated diphenylamine derivative, mix, and heat to 170° C. and reflux for 6 h under nitrogen, cool to 40° C., add 10 mL of 0.05 mol / L manganese nitrate solution, adjust the pH to 8, stir to react for 3 h, and distill under reduced pressure to obtain a functionalized diphenylamine derivative;

[0047] Step A4, 0.04 mol of methyl orthosilicate and 100 mL of ethanol aqueous solution were mixed, stirred for 30 min under nitrogen and ice-water bath, and then 0.2 mol of dimethylchlorosilane was added, stirred for 3 h, 0.3 mL of concentrated sulfuric acid was added dropwise and stirred for 20 min, and the organosilicon layer was separated and collected, washed, extracted and dried to obtain hydrogenated organosilicon, wherein the volume ratio of ethanol to water in the ethanol solution was 7:3;

[0048] Step A5, mix 0.2 mol of functionalized diphenylamine derivative, 200 mL of toluene and 10 mL of chloroplatinic acid isopropanol solution, add 0.1 mol of hydrogenated organosilicon under nitrogen at 80°C, stir and react for 3 h, then add 0.4 mol of isocyanoethyl methacrylate and continue to react for 3 h, filter and dry to obtain functionalized organosilicon. The chloroplatinic acid isopropanol solution is prepared by mixing chloroplatinic acid and isopropanol in a ratio of 0.07 g:10 mL.

[0049] Example 4: A method for preparing a bio-based nylon thermal insulation material resistant to heat and oxygen aging comprises the following steps:

[0050] The raw materials were weighed by weight, and 45 parts of PA610 nylon material, 5 parts of glass fiber, 8 parts of SEBS, 3 parts of functionalized silicone prepared in Example 1, 0.02 parts of antioxidant 168, 1 part of calcium stearate and 0.5 parts of KH570 were mixed, put into a twin-screw extruder, extruded at 210° C., cooled, dried and pelletized to obtain a bio-based nylon thermal insulation material resistant to heat and oxygen aging.

[0051] Example 5: A method for preparing a bio-based nylon thermal insulation material resistant to heat and oxygen aging comprises the following steps:

[0052] The raw materials were weighed by weight, and 50 parts of PA56 nylon material, 6 parts of glass fiber, 10 parts of maleic anhydride grafted POE, 4.5 parts of functionalized silicone prepared in Example 2, 0.04 parts of antioxidant 168, 1.5 parts of zinc stearate and 1 part of KH560 were mixed, put into a twin-screw extruder, extruded at 220°C, cooled, dried and pelletized to obtain a bio-based nylon thermal insulation material resistant to heat and oxygen aging.

[0053] Example 6: A method for preparing a bio-based nylon thermal insulation material resistant to heat and oxygen aging comprises the following steps:

[0054] The raw materials were weighed by weight, and 55 parts of PA1010 nylon material, 8 parts of glass fiber, 12 parts of maleic anhydride grafted POE, 6 parts of functionalized silicone prepared in Example 3, 0.05 parts of antioxidant 168, 2 parts of zinc stearate and 2 parts of KH550 were mixed, put into a twin-screw extruder, extruded at 230° C., cooled, dried and pelletized to obtain a bio-based nylon thermal insulation material resistant to heat and oxygen aging.

[0055] Comparative Example 1: This comparative example is a bio-based nylon thermal insulation material, which is different from Example 6 in that epoxidized silicone is used instead of the functional silicone prepared in Example 3, and the rest is the same;

[0056] The epoxy silicone is prepared by the following steps: 0.5 mol of allyl glycidyl ether, 200 mL of toluene and 10 mL of chloroplatinic acid isopropanol solution are mixed, and 0.1 mol of hydrogen-containing silicone is added under nitrogen at 80°C, stirred for reaction for 3 hours, filtered and dried to obtain epoxy silicone. The chloroplatinic acid isopropanol solution is prepared by mixing chloroplatinic acid and isopropanol in a ratio of 0.07 g:10 mL.

[0057] Comparative Example 2: This comparative example is a bio-based nylon thermal insulation material. The difference from Example 6 is that the functionalized silicone prepared in Example 3 is not added, and the rest is the same.

[0058] The bio-based nylon thermal insulation materials prepared in Examples 4-6 and Comparative Examples 1-2 were injection molded into test standard specimens to conduct thermal oxygen aging resistance tests:

[0059] The test specimens were placed in a thermal oxygen aging test chamber, the experimental temperature was set to 160°C, ventilation was performed once every minute, the speed was 30r / min, and aging was performed for 50 days. The tensile properties and tensile property retention rate of the test specimens before and after thermal oxygen aging were tested. The tensile strength was tested according to GB / T 23615.1-2009 standard. The tensile strength retention rate (%) = tensile strength of the specimen after aging / tensile strength of the specimen before aging × 100%;

[0060] The test results are shown in Table 1:

[0061] Table 1: Performance test results

[0062]

[0063] As can be seen from Table 1, after the thermal oxidative aging performance test, the tensile strength retention rate of the bio-based nylon thermal insulation material resistant to thermal oxidative aging prepared by the present invention is 85.7%-92.0%, indicating that the material has excellent thermal oxidative aging resistance.

[0064] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A bio-based nylon thermal insulation material resistant to heat and oxygen aging, characterized in that: The invention comprises the following raw materials in parts by weight: 45-55 parts of bio-based nylon material, 5-8 parts of glass fiber, 8-12 parts of toughening agent, 3-6 parts of functionalized silicone, 0.02-0.05 parts of antioxidant, 1-2 parts of lubricant, and 0.5-2 parts of coupling agent; The functionalized organosilicon is prepared by a hydrosilylation reaction of a functionalized diphenylamine derivative, isocyanoethyl methacrylate and hydrogen-containing organosilicon; the functionalized diphenylamine derivative is prepared by a mixed reaction of a carboxylated diphenylamine derivative, allylamine and manganese nitrate; the carboxylated diphenylamine derivative is prepared by an esterification reaction of a terminal hydroxyl diphenylamine derivative and ethylenediaminetetraacetic acid; the terminal hydroxyl diphenylamine derivative is prepared by a reaction of 4-(phenylamino)benzaldehyde and p-aminophenol; The bio-based nylon material is one of PA610 nylon material, PA56 nylon material and PA1010 nylon material; The toughening agent is one of SEBS or maleic anhydride grafted POE; The antioxidant is a phosphite antioxidant; The lubricant is one of zinc stearate or calcium stearate.

2. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 1, characterized in that: The functionalized silicone is prepared by the following steps: Step A1, 4-(phenylamino)benzaldehyde, p-aminophenol and toluene are mixed, condensed and refluxed for 4-6 hours under nitrogen and 115° C., transferred to benzene and allowed to stand for 10 minutes, filtered, washed and dried to obtain a terminal hydroxy diphenylamine derivative; Step A2, adding ethylenediaminetetraacetic acid, p-toluenesulfonic acid and DMF to the terminal hydroxyl diphenylamine derivative, mixing, heating to 120-140° C., stirring for 6 h, rotary evaporation and drying to obtain a carboxylated diphenylamine derivative; Step A3, adding allylamine and DMF to the carboxylated diphenylamine derivative, mixing, and heating to 160-170° C. and reflux for 4-6 hours under nitrogen, cooling to 40° C., adding 0.01-0.05 mol / L manganese nitrate solution, adjusting the pH to 8, stirring the reaction for 2-3 hours, and distilling under reduced pressure to obtain a functionalized diphenylamine derivative; Step A4, methyl orthosilicate and ethanol aqueous solution are mixed, stirred for 30 minutes under nitrogen and ice-water bath, dimethylchlorosilane is added, stirred for 3 hours, concentrated sulfuric acid is added dropwise and stirred for 20 minutes, the organosilicon layer is separated and collected, washed, extracted and dried to obtain hydrogen-containing organosilicon; Step A5, mix the functionalized diphenylamine derivative, toluene and isopropanol solution of chloroplatinic acid, add hydrogenated organosilicon under nitrogen at 80°C, stir and react for 2-3h, then add isocyanoethyl methacrylate and continue to react for 2-3h, filter and dry to obtain the functionalized organosilicon.

3. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 2, characterized in that: The molar ratio of 4-(phenylamino)benzaldehyde to p-aminophenol in step A1 is 1:

1.

4. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 2, characterized in that: In step A2, the molar ratio of ethylenediaminetetraacetic acid to the terminal hydroxy diphenylamine derivative is 1:1-2, and the amount of p-toluenesulfonic acid is 0.5%-1.5% of the mass of the terminal hydroxy diphenylamine derivative.

5. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 2, characterized in that: In step A3, the mass ratio of the carboxylated diphenylamine derivative, allylamine and manganese nitrate solution is 0.1 mol: 0.1 mol: 10 mL.

6. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 2, characterized in that: In step A4, the dosage ratio of methyl orthosilicate, dimethylchlorosilane and concentrated sulfuric acid is 0.04 mol: 0.18-0.2 mol: 0.2-0.3 mL, and the volume ratio of ethanol to water in the ethanol solution is 7:

3.

7. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 2, characterized in that: In step A5, the dosage ratio of the functionalized diphenylamine derivative, hydrogenated silicone, isocyanoethyl methacrylate and chloroplatinic acid isopropanol solution is 0.2-0.4 mol: 0.1 mol: 0.2-0.4 mol: 10 mL, and the chloroplatinic acid isopropanol solution is prepared by mixing chloroplatinic acid and isopropanol in a ratio of 0.05-0.07 g: 10 mL.

8. The bio-based nylon thermal insulation material resistant to heat and oxygen aging according to claim 1, characterized in that: The phosphite antioxidant is antioxidant 168.

9. A method for preparing the bio-based nylon thermal insulation material resistant to heat and oxygen aging as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: The raw materials are weighed by weight, the bio-based nylon material, glass fiber, toughening agent, functional silicone, antioxidant, lubricant and coupling agent are mixed, and the mixture is put into a twin-screw extruder, extruded at 210-230° C., cooled, dried and pelletized to obtain a bio-based nylon thermal insulation material resistant to heat and oxygen aging.

Images