Preparation method of optical-grade transparent bio-based nylon 510 polymer

Abstract

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

Description

Technical Field

[0001] The invention relates to the technical field of transparent nylon polymer materials, and in particular to a method for preparing an optical-grade transparent bio-based nylon 510 polymer. Background Art

[0002] Bio-based nylon is a polymer material synthesized by using biomass renewable resources as raw materials, and manufacturing monomers for synthesizing polyamides through biological, chemical and physical means, including bio-based lactams, bio-based dibasic acids, bio-based diamines, etc., and then synthesized through polymerization reaction. It has the characteristics of being green, environmentally friendly, and renewable raw materials. Most of the existing technologies introduce side chains or ring-shaped monomers into the nylon main chain to destroy the regularity of its molecular chain to reduce its crystallinity. Or a nucleating agent is added during the preparation process to form microcrystals and improve its transparency. For example, Chinese invention patent CN115594840A discloses a bio-based copolymer transparent nylon and its preparation method, which introduces isosorbide monomers into the nylon main chain to reduce its crystallinity and obtain transparent nylon. Although the existing technology can obtain transparent nylon, the transparency and mechanical properties of transparent nylon cannot meet higher requirements.

[0003] Therefore, it is of great significance to develop an optically 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 an optical grade transparent bio-based nylon 510 polymer to solve the problems of low transparency and poor mechanical properties of the transparent nylon prepared by the prior art.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

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

[0007] Nylon 510 salt, a catalyst, an antioxidant, an imidazole ionic liquid and a solvent are mixed, prepolymerized and melt-polymerized in sequence, and then low-temperature treated to obtain optical grade transparent bio-based nylon.

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

[0009] Preferably, the antioxidant includes antioxidant 1010, dilauryl thiodipropionate, distearyl 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, 1-vinyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium phosphate, 1-butyl-3-methylimidazolium dimethyl phosphate or 1-butyl-3-methylimidazolium acetate; and the solvent includes water.

[0011] Preferably, the mass fraction of the mixed solution composed of the nylon 510 salt and the solvent is 50-70%; the mass of the catalyst is 0.1-0.5% of the mass of the mixed solution composed of the nylon 510 salt and the solvent; the mass of the antioxidant is 0.1-0.5% of the mass of the mixed solution composed of the nylon 510 salt and the solvent; the mass of the imidazole ionic liquid is 1-10% of the mass of the mixed solution composed of the nylon 510 salt and the 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 normal 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 vent air, and melt polymerization is carried out when the pressure in the reactor reaches normal pressure.

[0015] Preferably, vacuuming is performed after the melt polymerization is completed, and the vacuuming time is 10 to 60 minutes.

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

[0017] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention introduces a monomer containing a side chain or a ring structure into the main chain to destroy the regularity of the nylon molecular chain, reduce hydrogen bonding and crystallinity, and obtain amorphous non-crystalline nylon. The crystallinity is reduced or fine crystals are formed, and the light transmittance, i.e., the light transmittance, will increase, thereby improving the transparency of the obtained optical grade transparent bio-based nylon 510 polymer. At the same time, the imidazole ionic liquid has an imidazole ring, which can be introduced into the main chain to destroy the regularity of the nylon molecular chain, reduce hydrogen bonding and crystallinity, and further improve the transparency of the obtained optical grade transparent bio-based nylon 510 polymer.

[0019] (2) After the polymerization is completed, the present invention allows the polymer to be quenched when it is discharged, which can significantly reduce its crystallinity, thereby obtaining an 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 of the present invention has a light transmittance of 85-90% and a tensile strength of 65-70 MPa, and has excellent mechanical strength and high transparency. DETAILED DESCRIPTION

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

[0022] Nylon 510 salt, a catalyst, an antioxidant, an imidazole ionic liquid and a solvent are mixed, prepolymerized and melt-polymerized in sequence, and then low-temperature treated to obtain optical grade transparent bio-based nylon.

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

[0024] The phosphorus-containing compounds include one or more of phosphoric acid, phosphorous acid, hypophosphorous acid, sodium hypophosphite, sodium metaphosphate, sodium pyrophosphate and aromatic substituted phosphoric acid; the boric acid compounds include one or more of boric acid, sodium borate and ammonium borate.

[0025] In the present invention, the antioxidant includes antioxidant 1010, dilauryl thiodipropionate, distearyl thiodipropionate, phenolic substances or amine substances;

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

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

[0028] In the present invention, 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, 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 the present invention, the mass fraction of the mixed solution composed of the nylon 510 salt and the solvent is preferably 50-70%, more preferably 55-65%, and more preferably 60-62%; the mass of the catalyst is preferably 0.1-0.5% of the mass of the mixed solution composed of the nylon 510 salt and the solvent, more preferably 0.2-0.4% of the mass of the mixed solution composed of the nylon 510 salt and the solvent, and more preferably 0.3% of the mass of the mixed solution composed of the nylon 510 salt and the solvent; the mass of the antioxidant is preferably 50-60% of the mass of the mixed solution composed of the nylon 510 salt and the solvent. The mass of the imidazole ionic liquid is preferably 1-10% of the mass of the mixed solution composed of the nylon 510 salt and the solvent, further preferably 4-8% of the mass of the mixed solution composed of the nylon 510 salt and the solvent, and more preferably 5-6% of the mass of the mixed solution composed of the nylon 510 salt and the solvent.

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

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

[0032] In the present 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 vent air, and melt polymerization is carried out when the pressure in the reactor reaches normal pressure.

[0033] In the present invention, vacuuming is performed after the melt polymerization is completed, and 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 the present 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 are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope 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-methylimidazole acetate, add them into a reactor, prepolymerize at 200°C and 1MPa for 2h, open the vent valve and slowly vent for 1h to normal pressure, heat to 260°C and carry out melt polymerization under closed normal pressure conditions, melt polymerization for 80min, vacuum for 10min, open the feed valve and pressurize the material into a -5°C ice water bath to obtain an optical grade transparent bio-based nylon 510 polymer.

[0038] It has been measured that the optical grade transparent bio-based nylon 510 polymer has a transmittance of 85%, a haze of 6.5%, a melting point of 216°C, a decomposition temperature of 405°C, 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-methylimidazole acetate, add them into a reactor, prepolymerize at 200°C and 1MPa for 2h, open the vent valve and slowly vent for 1h to normal pressure, heat to 260°C and carry out melt polymerization under closed normal pressure conditions, melt polymerization for 80min, evacuate for 10min, open the feed valve and pressurize and extrude the material into a water tank at normal temperature to obtain an optical grade transparent bio-based nylon 510 polymer.

[0041] It has been measured that the optical grade transparent bio-based nylon 510 polymer has a transmittance of 87%, a haze of 5.6%, a melting point of 217°C, a decomposition temperature of 410°C, 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-methylimidazole acetate, add them into a reactor, prepolymerize at 200°C and 1MPa for 2h, open the vent valve and slowly vent for 1h to normal pressure, heat to 260°C and carry out melt polymerization under closed normal pressure conditions, melt polymerization for 80min, vacuum for 10min, open the feed valve and pressurize the material into a -5°C ice water bath to obtain an optical grade transparent bio-based nylon 510 polymer.

[0044] It has been measured that the optical grade transparent bio-based nylon 510 polymer has a transmittance of 90%, a haze of 4.3%, a melting point of 217°C, a decomposition temperature of 409°C, and a tensile strength of 65MPa.

[0045] From Examples 1 to 3 and the test results of the obtained optical grade transparent bio-based nylon 510 polymer, it can be seen that 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 is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as 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 steps include: Nylon 510 salt, a catalyst, an antioxidant, an imidazole ionic liquid and a solvent are mixed, prepolymerized and melt-polymerized in sequence, and then low-temperature treated to obtain optical grade transparent bio-based nylon.

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

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 includes antioxidant 1010, dilauryl thiodipropionate, distearyl 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 imidazolium 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, 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.

5. The method for preparing the optical grade transparent bio-based nylon 510 polymer according to claim 1, 2 or 4, characterized in that: The mass fraction of the mixed solution composed of the nylon 510 salt and the solvent is 50-70%; the mass of the catalyst is 0.1-0.5% of the mass of the mixed solution composed of the nylon 510 salt and the solvent; the mass of the antioxidant is 0.1-0.5% of the mass of the mixed solution composed of the nylon 510 salt and the solvent; the mass of the imidazole ionic liquid is 1-10% of the mass of the mixed solution composed of the nylon 510 salt and the solvent.

6. The method for preparing the optical grade transparent bio-based nylon 510 polymer according to claim 5, characterized in that: The prepolymerization temperature is 150-250° C., the prepolymerization pressure is 0.8-1.5 MPa, and the prepolymerization time is 1-3 hours.

7. The method for preparing the optical grade transparent bio-based nylon 510 polymer according to claim 6, characterized in that: The temperature of the melt polymerization is 250-300° C., the pressure of the melt polymerization is normal pressure, and the time of the melt polymerization is 60-300 min.

8. The method for preparing the optical grade transparent bio-based nylon 510 polymer according to claim 6 or 7, 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 vent air, and melt polymerization is carried out when the pressure in the reactor reaches normal pressure.

9. The method for preparing the optical grade transparent bio-based nylon 510 polymer according to claim 8, characterized in that: After the melt polymerization is completed, vacuuming is performed, and the vacuuming time is 10 to 60 minutes.

10. The method for preparing the optical grade transparent bio-based nylon 510 polymer according to claim 9, characterized in that: The temperature of the low temperature treatment is -5 to 30°C.