A method for preparing an optical grade transparent bio-based nylon 510 polymer

Abstract

The application belongs to the technical field of polymer material transparent nylon, and discloses a preparation method of optical-grade transparent bio-based nylon 510 polymer. The preparation method comprises the following steps: mixing nylon 510 salt, a catalyst, an antioxidant, an imidazole ionic liquid and a solvent, and then sequentially performing pre-polymerization and melt polymerization, and then performing low-temperature treatment to obtain the optical-grade transparent bio-based nylon. The optical-grade transparent bio-based nylon 510 polymer prepared by the method has a light transmittance of 85-90%, and a tensile strength of 65-70 MPa, and has excellent mechanical strength and high transparency.

Description

A method for preparing an optical-grade transparent bio-based nylon 510 polymer Technical Field

[0001] This invention relates to the field of transparent nylon polymer technology, and more particularly to a method for preparing an optical-grade transparent bio-based nylon 510 polymer. Background Technology

[0002] Bio-based nylon is a polymer material synthesized from biomass renewable resources through biological, chemical, and physical methods to produce monomers for polyamide synthesis, including bio-based lactams, bio-based diacids, and bio-based diamines. It possesses characteristics such as being green, environmentally friendly, and using renewable raw materials. Most existing technologies introduce side chains or cyclic monomers into the nylon backbone to disrupt its molecular chain regularity and reduce its crystallinity. Alternatively, nucleating agents are added during preparation to form microcrystals and improve transparency. For example, Chinese invention patent CN115594840A discloses a bio-based copolymer transparent nylon and its preparation method, which introduces isosorbide monomer into the nylon backbone to reduce its crystallinity and obtain transparent nylon. Although existing technologies can produce transparent nylon, its transparency and mechanical properties cannot meet the requirements of more demanding applications.

[0003] Therefore, it is of great significance to develop an optical-grade transparent bio-based nylon 510 polymer with high transparency and excellent mechanical properties. Summary of the Invention

[0004] In view of this, the present invention provides a method for preparing optical-grade transparent bio-based nylon 510 polymer to solve the problems of low transparency and poor mechanical properties of transparent nylon prepared by existing technologies.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a method for preparing optical-grade transparent bio-based nylon 510 polymer, comprising the following steps:

[0007] Nylon 510 salt, catalyst, antioxidant, imidazole ionic liquid and solvent were mixed and then subjected to prepolymerization and melt polymerization in sequence, followed by low temperature treatment to obtain optical grade transparent bio-based nylon.

[0008] Preferably, the catalyst includes sodium hydroxide, toluene diisocyanate, phosphorus-containing compounds, or boric acid compounds.

[0009] Preferably, the antioxidant includes antioxidant 1010, dilaurate thiodipropionate, distearate thiodipropionate, phenolic substances, or amine substances.

[0010] Preferably, the imidazole ionic liquid includes 1-vinyl-3-methylimidazolium acetate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, 1-vinyl-3-butylimidazolium dibutyl phosphate, 1-vinyl-3-ethylimidazolium dinitrile amine salt, 1-vinyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium phosphate, 1-butyl-3-methylimidazolium dimethyl phosphate, or 1-butyl-3-methylimidazolium acetate; the solvent includes water.

[0011] Preferably, the mass fraction of the mixture of nylon 510 salt and solvent is 50-70%; the mass of the catalyst is 0.1-0.5% of the mass of the mixture of nylon 510 salt and solvent; the mass of the antioxidant is 0.1-0.5% of the mass of the mixture of nylon 510 salt and solvent; and the mass of the imidazole ionic liquid is 1-10% of the mass of the mixture of nylon 510 salt and solvent.

[0012] Preferably, the prepolymerization temperature is 150–250°C, the prepolymerization pressure is 0.8–1.5 MPa, and the prepolymerization time is 1–3 h.

[0013] Preferably, the temperature of the melt polymerization is 250–300°C, the pressure of the melt polymerization is atmospheric pressure, and the time of the melt polymerization is 60–300 min.

[0014] Preferably, the prepolymerization and melt polymerization are carried out in a reactor; after the prepolymerization is completed, the vent valve of the reactor is opened to release the gas until the pressure inside the reactor is at atmospheric pressure, at which point melt polymerization is carried out.

[0015] Preferably, after the melt polymerization is completed, a vacuum is applied for 10 to 60 minutes.

[0016] Preferably, the temperature of the low-temperature treatment is -5 to 30°C.

[0017] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) This invention introduces monomers containing side chains or cyclic structures into the main chain, disrupting the regularity of the nylon molecular chain, reducing hydrogen bonds and crystallinity, and obtaining amorphous amorphous nylon. The reduced crystallinity or the formation of fine crystals increases light transmittance, thereby improving the transparency of the resulting optical-grade transparent bio-based nylon 510 polymer. Simultaneously, imidazole ionic liquids with imidazole rings can be introduced into the main chain to disrupt the regularity of the nylon molecular chain, reduce hydrogen bonds and crystallinity, and further improve the transparency of the resulting optical-grade transparent bio-based nylon 510 polymer.

[0019] (2) In this invention, the polymer is rapidly cooled during discharge after polymerization, which can significantly reduce its crystallinity, thereby obtaining optical-grade transparent bio-based nylon 510 polymer with high transparency.

[0020] (3) The optical grade transparent bio-based nylon 510 polymer prepared by the method described in this invention has a light transmittance of 85-90% and a tensile strength of 65-70 MPa, exhibiting excellent mechanical strength and high transparency. Detailed Implementation

[0021] This invention provides a method for preparing optical-grade transparent bio-based nylon 510 polymer, comprising the following steps:

[0022] Nylon 510 salt, catalyst, antioxidant, imidazole ionic liquid and solvent were mixed and then subjected to prepolymerization and melt polymerization in sequence, followed by low temperature treatment to obtain optical grade transparent bio-based nylon.

[0023] In this invention, the catalyst includes sodium hydroxide, toluene diisocyanate, phosphorus-containing compounds, or boric acid compounds;

[0024] Phosphorus-containing compounds include one or more of phosphoric acid, phosphorous acid, hypophosphoric acid, sodium hypophosphite, sodium metaphosphate, sodium pyrophosphate, and aryl-substituted phosphoric acid; boric acid compounds include one or more of boric acid, sodium borate, and ammonium borate.

[0025] In this invention, the antioxidants include antioxidant 1010, dilaurate thiodipropionate, distearate thiodipropionate, phenolic substances, or amine substances.

[0026] The phenolic substances include monophenols and / or polyphenols; the polyphenols include hydroquinone and / or thiobisphenols.

[0027] The amines include one or more of naphthylamine, diphenylamine, and p-phenylenediamine.

[0028] In this invention, the imidazole ionic liquid includes 1-vinyl-3-methylimidazolium acetate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, 1-vinyl-3-butylimidazolium phosphate dibutyl ester, 1-vinyl-3-ethylimidazolium dinitrile amine salt, 1-vinyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium phosphate, 1-butyl-3-methylimidazolium dimethyl phosphate, or 1-butyl-3-methylimidazolium acetate; the solvent includes water.

[0029] In this invention, the mass fraction of the mixture composed of nylon 510 salt and solvent is preferably 50-70%, more preferably 55-65%, and even more preferably 60-62%; the mass fraction of the catalyst is preferably 0.1-0.5% of the mass fraction of the mixture composed of nylon 510 salt and solvent, more preferably 0.2-0.4% of the mass fraction of the mixture composed of nylon 510 salt and solvent, and even more preferably 0.3% of the mass fraction of the mixture composed of nylon 510 salt and solvent; the mass fraction of the antioxidant is preferably the mass fraction of the mixture composed of nylon 510 salt and solvent. The mass of the mixture is 0.1-0.5% of the total mass of the nylon 510 salt and solvent, more preferably 0.15-0.4% of the total mass of the mixture of nylon 510 salt and solvent, and even more preferably 0.2-0.35% of the total mass of the mixture of nylon 510 salt and solvent; the mass of the imidazole ionic liquid is preferably 1-10% of the total mass of the mixture of nylon 510 salt and solvent, more preferably 4-8% of the total mass of the mixture of nylon 510 salt and solvent, and even more preferably 5-6% of the total mass of the mixture of nylon 510 salt and solvent.

[0030] In this invention, the prepolymerization temperature is preferably 150–250°C, more preferably 180–220°C, and even more preferably 200–210°C; the prepolymerization pressure is preferably 0.8–1.5 MPa, more preferably 1–1.4 MPa, and even more preferably 1.2–1.3 MPa; and the prepolymerization time is preferably 1–3 h, more preferably 1.5–2.5 h, and even more preferably 2 h.

[0031] In this invention, the temperature of the melt polymerization is preferably 250-300°C, more preferably 260-290°C, and even more preferably 270-280°C; the pressure of the melt polymerization is atmospheric pressure; and the time of the melt polymerization is preferably 60-300 min, more preferably 80-200 min, and even more preferably 90-120 min.

[0032] In this invention, the prepolymerization and melt polymerization are carried out in a reactor; after the prepolymerization is completed, the vent valve of the reactor is opened to release the gas, and melt polymerization is carried out when the pressure inside the reactor is at atmospheric pressure.

[0033] In this invention, after the melt polymerization is completed, a vacuum is drawn. The vacuuming time is preferably 10 to 60 minutes, more preferably 20 to 50 minutes, and even more preferably 30 to 40 minutes.

[0034] In this invention, the temperature of the low-temperature treatment is preferably -5 to 30°C, more preferably -2 to 25°C, and even more preferably 0 to 20°C.

[0035] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0036] Example 1

[0037] Weigh 50.21g of nylon 510 salt, 33.47g of deionized water, 0.2510g of sodium hypophosphite, 0.0837g of antioxidant 1010, and 2.5104g of 1-vinyl-3-methylimidazolium acetate, and add them together to a reactor. Prepolymerize at 200℃ and 1MPa for 2 hours. Open the vent valve and slowly release the gas for 1 hour to normal pressure. Heat to 260℃ and melt polymerize under closed normal pressure for 80 minutes. After vacuuming for 10 minutes, open the discharge valve and pressurize to extrude the material into a -5℃ ice-water bath to obtain optical-grade transparent bio-based nylon 510 polymer.

[0038] The optical-grade transparent bio-based nylon 510 polymer has a light transmittance of 85%, a haze of 6.5%, a melting point of 216℃, a decomposition temperature of 405℃, and a tensile strength of 70MPa.

[0039] Example 2

[0040] Weigh 50.30g of Nylon 510 salt, 33.83g of deionized water, 0.2524g of sodium hypophosphite, 0.0841g of antioxidant 1010, and 4.2065g of 1-vinyl-3-methylimidazolium acetate, and add them together to a reactor. Prepolymerize at 200℃ and 1MPa for 2 hours. Open the vent valve and slowly release the gas for 1 hour to normal pressure. Heat to 260℃ and melt polymerize under closed normal pressure for 80 minutes. After vacuuming for 10 minutes, open the discharge valve and pressurize to extrude the material into a room temperature water bath to obtain optical grade transparent bio-based Nylon 510 polymer.

[0041] The optical-grade transparent bio-based nylon 510 polymer has a light transmittance of 87%, a haze of 5.6%, a melting point of 217℃, a decomposition temperature of 410℃, and a tensile strength of 69MPa.

[0042] Example 3

[0043] Weigh 50.05g of nylon 510 salt, 33.37g of deionized water, 0.2503g of sodium hypophosphite, 0.08342g of antioxidant 1010, and 8.3420g of 1-vinyl-3-methylimidazolium acetate, and add them together to a reactor. Prepolymerize at 200℃ and 1MPa for 2 hours. Open the vent valve and slowly release the gas for 1 hour to normal pressure. Heat to 260℃ and melt polymerize under closed normal pressure for 80 minutes. After vacuuming for 10 minutes, open the discharge valve and pressurize to extrude the material into a -5℃ ice-water bath to obtain optical-grade transparent bio-based nylon 510 polymer.

[0044] The optical-grade transparent bio-based nylon 510 polymer has a light transmittance of 90%, a haze of 4.3%, a melting point of 217℃, a decomposition temperature of 409℃, and a tensile strength of 65MPa.

[0045] As can be seen from Examples 1-3 and the test results of the obtained optical-grade transparent bio-based nylon 510 polymer, the optical-grade transparent bio-based nylon 510 polymer obtained by the method of the present invention has excellent mechanical strength and transparency.

[0046] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an optical-grade transparent bio-based nylon 510 polymer, characterized in that, The process includes the following steps: mixing nylon 510 salt, catalyst, antioxidant, imidazole ionic liquid, and solvent, followed by sequential prepolymerization and melt polymerization, and then low-temperature treatment to obtain optical-grade transparent bio-based nylon; the melt polymerization pressure is atmospheric pressure; the low-temperature treatment temperature is -5~30℃; the mass fraction of the mixture of nylon 510 salt and solvent is 50~70%; the mass of the catalyst is 0.1~0.5% of the mass of the mixture of nylon 510 salt and solvent; the mass of the antioxidant is 0.1~0.5% of the mass of the mixture of nylon 510 salt and solvent; the mass of the imidazole ionic liquid is 1~10% of the mass of the mixture of nylon 510 salt and solvent; the prepolymerization temperature is 150~250℃, the prepolymerization pressure is 0.8~1.5MPa; and the melt polymerization temperature is 250~300℃.

2. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 1, characterized in that, The catalyst is selected from sodium hydroxide, toluene diisocyanate, phosphorus-containing compounds, or boric acid compounds.

3. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 1 or 2, characterized in that, The antioxidant is selected from dilaurate thiodipropionate, distearate thiodipropionate, phenolic substances, or amine substances.

4. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 3, characterized in that, The imidazole ionic liquid is selected from 1-vinyl-3-methylimidazolium acetate, 1-vinyl-3-ethylimidazolium tetrafluoroborate, 1-vinyl-3-butylimidazolium phosphate dibutyl ester, 1-vinyl-3-ethylimidazolium dinitrile amine salt, 1-vinyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium phosphate, 1-butyl-3-methylimidazolium dimethyl phosphate, or 1-butyl-3-methylimidazolium acetate; the solvent is water.

5. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 1, characterized in that, The prepolymerization time is 1-3 hours.

6. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 5, characterized in that, The melt polymerization time is 60~300 min.

7. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 5 or 6, characterized in that, The prepolymerization and melt polymerization are carried out in a reactor; after the prepolymerization is completed, the vent valve of the reactor is opened to release the gas until the pressure inside the reactor is at atmospheric pressure, at which point melt polymerization is carried out.

8. The method for preparing the optical-grade transparent bio-based nylon 510 polymer according to claim 7, characterized in that, After the melt polymerization is completed, a vacuum is drawn for 10 to 60 minutes.