A polyoxalate and a method for preparing the same

Abstract

The application provides a polyoxalate and a preparation method thereof. The polyoxalate comprises structural units derived from oxalic acid and structural units derived from dihydric alcohol, the weight average molecular weight of the polyoxalate is 120,000-1,000,000 g / mol, the color of the polyoxalate is a color L value of 80-86, an a value of -4 to -2.0, and a b value of 1.5-10 according to the method B in the test method of color in GB / T14190-2008. The polyoxalate according to the application has the advantages of high molecular weight, large intrinsic viscosity, good color and the like.

Description

Technical Field

[0001] This invention belongs to the field of biodegradable materials technology, specifically relating to a polyoxalate and its preparation method. The method for preparing oxalate is time-efficient, and the prepared polyoxalate has the characteristics of high molecular weight, high intrinsic viscosity, good color, and excellent mechanical and heat resistance properties. Background Technology

[0002] The invention of plastics has brought tremendous convenience to human life, but it has also generated a large amount of difficult-to-manage plastic waste. Traditional plastics are derived from non-renewable petroleum resources and are difficult to degrade. Therefore, developing biodegradable materials to replace some traditional plastics is of great significance for the healthy and sustainable development of the plastics industry and environmental protection.

[0003] Currently, common biodegradable plastics include polylactic acid (PLA), polybutylene terephthalate (PBAT), polybutylene succinate (PBS), and polycaprolactone (PCL). Among these, PLA has poor toughness, limiting its applications; its raw material is derived from grains, and its production technology is complex and costly. PBAT has relatively low strength, limiting its applications when used alone. PBS is sensitive to moisture, has a small market size, and is expensive. PCL has low glass transition and melting temperatures, limiting its applications; its monomer production is also difficult and costly. In summary, the commercial application and promotion of most biodegradable plastics on the market are limited by the material's inherent properties, technological challenges, and production costs.

[0004] Polyoxalate (POO) is prepared by reacting oxalate or oxalic acid with diols. It features a high melting point (>100℃), excellent mechanical properties, and a wide processing window. PEO also exhibits excellent biodegradability, completely hydrolyzing in water, making it suitable for applications requiring short degradation times or as a modifier to adjust the biodegradability of other materials. PEO has a wide range of raw material sources and low production costs. Oxalic acid, derived from biomass renewable resources, is widely distributed in plants, animals, and fungi, and can also be prepared chemically. my country, as the world's largest producer of oxalic acid, primarily uses the sodium formate method and carbohydrate oxidation method. Currently, my country's total oxalic acid production reaches 1.2 million tons per year and is growing rapidly. Dioxate mainly comes from chemical production processes, with dimethyl oxalate being the most important intermediate product in the coal-to-ethylene glycol process, with a total annual production capacity of 20 million tons nationwide. Therefore, both oxalate and oxalic acid are very inexpensive.

[0005] Currently, the commonly used methods for synthesizing polyoxalate mainly include esterification and transesterification. Esterification involves the direct esterification and dehydration of oxalic acid and a diol, followed by high-temperature polycondensation to prepare polyoxalate. This method often requires a polycondensation temperature exceeding 200℃ in the later stages. At this temperature, oxalic acid undergoes decarboxylation, thermal oxidation, and degradation reactions, resulting in a black-colored polyoxalate with a low molecular weight.

[0006] Transesterification involves the exchange of oxalate diesters (such as dimethyl oxalate and diethyl oxalate) with diols, followed by melt polycondensation or solid-state polycondensation to prepare polyoxalate. Melt polycondensation is simple and produces high molecular weight polymers, but the high temperatures (≥200℃) in the later stages of polymerization can still cause decarboxylation, thermal oxidation, and degradation, resulting in a decrease in molecular weight and darkening of color. Solid-state polycondensation has a lower polymerization temperature, significantly reducing or inhibiting polymerization side reactions caused by thermal decomposition and thermal oxidation, effectively increasing the molecular weight of polyoxalate and the monomer conversion rate; however, the reaction time is generally several tens of hours. CN102718948B uses solid-state polycondensation at 100–125℃ and an absolute pressure <100Pa for 30–55 hours to prepare polyoxalate, and the final product still has a relatively low intrinsic viscosity.

[0007] In summary, both esterification and transesterification methods suffer from slow polycondensation rates, low molecular weight, and poor color. Summary of the Invention

[0008] To address the above problems, this invention provides a method for rapidly preparing polyoxalate with high molecular weight, high intrinsic viscosity, and good color. This invention significantly reduces the transesterification and polycondensation reaction temperatures required for polyoxalate synthesis by using highly efficient catalysts and accelerators, thus solving problems related to raw material volatilization and sublimation, side reactions, slow polycondensation reaction rates, and low product molecular weight. The addition of heat stabilizers and antioxidants to inhibit thermal decomposition during the polycondensation process further enhances the product's color.

[0009] The polyoxalate prepared by this invention has the characteristics of high molecular weight, high intrinsic viscosity, good color, and excellent mechanical and heat resistance properties.

[0010] According to a first aspect of the invention, a polyoxalate is provided, comprising structural units derived from oxalic acid and structural units derived from diols, wherein...

[0011] The polyoxalate has a weight-average molecular weight of 120,000 to 10,000,000 g / mol, preferably 150,000 to 500,000 g / mol;

[0012] The color of the polyoxalate was determined according to Method B of the colorimetric test method in GB / T14190-2008, with a colorimetric L value of 80 to 86, an a value of -4 to -2.0, preferably -4 to -2.5, and a b value of 1.5 to 10.

[0013] Preferably, the intrinsic viscosity of the polyoxalate is 0.5 to 4.0 dL / g, more preferably 0.9 to 4.0 dL / g, as determined by method A in the test method for intrinsic viscosity in GB / T 14190-2008.

[0014] Preferably, the diol is selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,4-pentanediol, neopentanediol, cyclohexanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 1,2-heptanediol, 1,7-heptanediol, 1,8-octanediol, etc. At least one of 1,2-octanediol, 1,2-nonanediol, 1,9-nonanediol, 1,2-decanediol, naphthalene-1,8-diol, 3-methyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methyl-1,3-propanediol, 2-phenyl-1,3-propanediol, 1-phenyl-1,2-ethylenediol, 2-ethyl-1,3-hexanediol, and isosorbide.

[0015] According to a second aspect of the present invention, a method for preparing polyoxalate is provided, the method comprising the following steps:

[0016] (1) Transesterification stage: Oxalic acid or oxalate diester, diol and catalyst are added to the reactor; then esterification reaction is carried out under an inert atmosphere (preferably nitrogen atmosphere) and heating conditions to obtain low molecular weight esters;

[0017] (2) Pre-polymerization stage: The low molecular weight ester obtained in step (1) is subjected to pre-polymerization reaction under heating and vacuum conditions to further increase the molecular weight;

[0018] (3) Final polycondensation stage: Heat stabilizer, antioxidant and accelerator are added to the reactor and the final polycondensation reaction is carried out at a temperature of 150-190°C, preferably 160-190°C and under vacuum conditions to obtain polyoxalate product.

[0019] The accelerator is an epoxy compound, a polyol containing three hydroxyl groups, or an ether or ester derived from the epoxy compound or polyol.

[0020] Preferably, the accelerator is selected from 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,3-heptanetriol, glycerol triglycidyl ether, ethoxylated glycerol triacrylate, 2-methyl-1,2,3-propanetriol, triglyceride tripropionate, dipentapentanol, tripentapentanol, pentaerythritol glycidyl ether, pentaerythritol propionate, pentaerythritol triallyl ether, pentaerythritol triacrylate, bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane), N-tris(hydroxymethyl)methacrylamide, methyl 2,3-epoxypropionate, allyl-2,3-epoxypropyl ether, 4,5-epoxytetrahydrophthalic acid diglycidyl ester, 1,4-cyclohexanediol bis(3,4-epoxycyclohexanecarboxylic acid), neopentyl dipropionate, etc. The product comprises at least one of the following: diglycidyl alcohol ether, D-sorbitol diglycidyl ether, resorcinol diglycidyl ether, diethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl p-aminophenol, 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, and hexahydrophthalic acid diglycidyl ester, more preferably selected from one or more combinations of pentaerythritol diglycidyl ether and trimethylolpropane triglycidyl ether.

[0021] Preferably, the oxalate diester is selected from at least one of dimethyl oxalate, diethyl oxalate, dipropyl oxalate and dibutyl oxalate, more preferably dimethyl oxalate and / or diethyl oxalate.

[0022] Preferably, the diol is selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,4-pentanediol, neopentanediol, cyclohexanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 1,2-heptanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, and 1,2-nonanediol. The alcohol, 1,9-nonanediol, 1,2-decanediol, naphthalene-1,8-diol, 3-methyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methyl-1,3-propanediol, 2-phenyl-1,3-propanediol, 1-phenyl-1,2-ethylenediol, 2-ethyl-1,3-hexanediol and isosorbide, more preferably one or more of ethylene glycol, 1,4-butanediol and isosorbide.

[0023] Preferably, in step (1), the molar ratio of the oxalate diester and / or oxalic acid to the diol is between 0.5:1 and 2:1, and more preferably between 0.9:1 and 1.2:1.

[0024] Preferably, the catalyst is selected from at least one of zinc oxalate dihydrate, tin oxalate, nano tin dioxide, bis(tri-n-butyltin) oxide, zinc hydroxystannate, monobutyltin oxide, butylstannic acid, tert-butoxytin, dimethyltin oxide, and dibutyltin dilaurate, more preferably one or two of dimethyltin oxide and monobutyltin oxide.

[0025] Preferably, in step (1), the amount of catalyst used is 1 / 100000 to 1 / 200 of the mass of the polyoxamate product, more preferably 1 / 10000 to 1 / 5000.

[0026] Preferably, the temperature of the esterification reaction in step (1) is 100-140°C, more preferably 110-130°C.

[0027] Preferably, the reaction time of the esterification reaction in step (1) is 1 to 4 hours, more preferably 2 to 3 hours.

[0028] Preferably, the reaction temperature of the pre-condensation reaction in step (2) is 100-140°C, more preferably 110-130°C.

[0029] Preferably, the vacuum degree of the pre-condensation reaction in step (2) is 1 to 100 kPa, more preferably 2 to 10 kPa.

[0030] Preferably, the reaction time of the pre-condensation reaction in step (2) is 0.5 to 3 hours, more preferably 1 to 2 hours.

[0031] Preferably, the vacuum degree of the final polycondensation reaction in step (3) is 0.1 to 200 Pa, more preferably 2 to 20 Pa.

[0032] Preferably, the reaction time of the final polycondensation reaction in step (3) is 1 to 4 hours, and more preferably 2 to 3 hours.

[0033] Preferably, the heat stabilizer is selected from at least one of didecyl phosphate, dibenzyl phosphate, octadecyl phosphate, tripentyl phosphate, trioctyl phosphate, triisobutyl phosphate, tri-m-toluene phosphate, tri-o-toluene phosphate, dibenzyl phosphite, di-tert-butyl phosphite, diisopropyl phosphite, diisobutyl phosphite, phenyl diisooctyl phosphite, trihexyl phosphite, trinepentyl phosphite, triisodecyl phosphite, and tri-o-toluene phosphite; more preferably, it is selected from one or two of tri-m-toluene phosphate and tri-o-toluene phosphite.

[0034] Preferably, the amount of heat stabilizer used is 1 / 10000 to 1 / 100 of the mass of the polyoxalate product, more preferably 1 / 10000 to 1 / 1000.

[0035] Preferably, the antioxidant is at least one selected from antioxidant 618, antioxidant 565, antioxidant 264, antioxidant 300, antioxidant 702, antioxidant 136, antioxidant 1098, antioxidant 1024, antioxidant 697, antioxidant 1135, antioxidant 5057, antioxidant 702, antioxidant 330, antioxidant 3114, antioxidant 1035, antioxidant 1425 and antioxidant 2246, more preferably one or two selected from antioxidant 618 and antioxidant 1024.

[0036] Preferably, the amount of antioxidant used is 1 / 10000 to 1 / 100 of the mass of the polyoxadenate product, more preferably 1 / 10000 to 1 / 1000.

[0037] Preferably, the amount of the accelerator is 1 / 10000 to 1 / 100 of the mass of the polyoxadenate product, more preferably 1 / 10000 to 1 / 1000.

[0038] According to a third aspect of the invention, the use of the accelerator according to the invention in the preparation of polyoxalate is provided, said accelerator being an epoxy compound, a polyol containing three or more hydroxyl groups, or an ether or ester derived from said epoxy compound or polyol. Preferably, the accelerator is selected from 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,3-heptanetriol, glycerol triglycidyl ether, ethoxylated glycerol triacrylate, 2-methyl-1,2,3-propanetriol, triglyceride tripropionate, dipentapentanol, tripentapentanol, pentaerythritol glycidyl ether, pentaerythritol propionate, pentaerythritol triallyl ether, pentaerythritol triacrylate, bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane), N-tris(hydroxymethyl)methacrylamide, methyl 2,3-epoxypropionate, allyl-2,3-epoxypropyl ether, 4,5-epoxytetrahydrophthalic acid diglycidyl ester, 1,4-cyclohexanediol bis(3,4-epoxycyclohexanecarboxylic acid), neopentyl dipropionate, etc. At least one of the following: diglycidyl alcohol ether, D-sorbitol diglycidyl ether, resorcinol diglycidyl ether, diethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl p-aminophenol, 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, and hexahydrophthalic acid diglycidyl ester, preferably selected from one or more combinations of pentaerythritol diglycidyl ether and trimethylolpropane triglycidyl ether.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] (1) The present invention uses a highly efficient catalyst and accelerator to greatly reduce the transesterification and polycondensation reaction temperature required for the synthesis of polyoxalate, and solves the problems of raw material volatilization and sublimation, side reactions, slow polycondensation reaction rate and low product molecular weight.

[0041] (2) The addition of heat stabilizers and antioxidants to inhibit thermal decomposition during the polycondensation process in this invention greatly improves the color of the product.

[0042] (3) The polyoxamate prepared by the present invention has the characteristics of high molecular weight, high intrinsic viscosity and good color.

[0043] (4) The polyoxarate preparation of this invention has a fast polycondensation rate, a wide range of raw material sources, and low cost, making it suitable for industrial production. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments. It should be noted that the embodiments are only used to illustrate the present invention, but the present invention is not limited thereto. The specific scope of protection is given in the claims.

[0045] The raw materials, including oxalate diester and diol, are all industrial grade. Other catalysts and additives are commercially available and of analytical purity. The equipment and methods used in this invention are all commonly used in the field.

[0046] The weight-average molecular weight (Mw) of the product was determined by GPC method, using dichloromethane as the mobile phase and polystyrene as the standard reference.

[0047] The intrinsic viscosity test method is as follows: Method A (capillary viscometer method) in section 5.1 (Test Methods for Intrinsic Viscosity) of GB / T 14190-2008 is used. The solvent used is phenol / 1,1,2,2-tetrachloroethane (mass ratio 50:50), with a sample weight of 0.125 g and 25 mL of solvent.

[0048] The test method for hue L value is as follows: the test shall be conducted according to Method B (drying method) in section 5.5 (Test Methods for Colorimetry) of GB / T14190-2008. The CIE1976 L*a*b* color system shall be adopted.

[0049] Example 1

[0050] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0051] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0052] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 1.44g of pentaerythritol glycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2549g of polyoxarate product.

[0053] The performance characterization results of polyoxalate are as follows: intrinsic viscosity is 1.5 dL / g, weight-average molecular weight Mw = 250456 g / mol, particle hue L value is 85, a value is -3.9, and b value is 2.

[0054] Example 2

[0055] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0056] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0057] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 2.88g of pentaerythritol glycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2495g of polyoxalate product.

[0058] The performance characterization results of polyoxalate are as follows: intrinsic viscosity is 2.56 dL / g, weight-average molecular weight Mw = 361569 g / mol, particle hue L value is 85.4, a value is -3.7, and b value is 2.3.

[0059] Example 3

[0060] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0061] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0062] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 1.44g of pentaerythritol glycidyl ether to the reactor, and carry out the final polycondensation reaction for 3 hours at 150℃ and 20Pa vacuum to prepare 2458g of polyoxalate product.

[0063] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 195641 g / mol, particle hue L value is 86, a value is -4.0, and b value is 1.5.

[0064] Example 4

[0065] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of 1,4-butanediol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0066] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0067] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 1.44g of pentaerythritol glycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 190℃ and 20Pa vacuum to prepare 2391g of polyoxarate product.

[0068] The performance characterization results of polyoxalate are as follows: intrinsic viscosity is 2.4 dL / g, weight-average molecular weight Mw = 354562 g / mol, particle hue L value is 83.5, a value is -3.5, and b value is 5.

[0069] Example 5

[0070] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0071] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0072] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 1.44g of 1,2,4-butanetriol to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2594g of polyoxalate product.

[0073] Performance characterization results of polyoxalate: intrinsic viscosity is 1.1 dL / g, weight-average molecular weight Mw = 165194 g / mol, particle hue L value is 84.2, a value is -3.2, and b value is 8.5.

[0074] Example 6

[0075] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0076] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0077] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 1.44g of tripentapentanol to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2512g of polyoxalate product.

[0078] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 182584 g / mol, particle hue L value is 84.1, a value is -3.4, and b value is 6.8.

[0079] Example 7

[0080] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0081] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0082] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1024 and 1.44g of diethylene glycol diglycidyl ether to the reactor, and carry out the final polycondensation reaction for 3 hours at 180℃ and 20Pa vacuum to prepare 2623g of polyoxalate product.

[0083] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.5 dL / g, weight-average molecular weight Mw = 201394 g / mol, particle hue L value is 84.3, a value is -3.6, and b value is 5.5.

[0084] Example 8

[0085] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0086] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0087] Step (3) Final polycondensation stage: Add 1.044g of trimethyl-m-toluene phosphate, 1.152g of antioxidant 1024 and 1.44g of 2-methyl-1,2,3-propanetriol to the reactor, and carry out the final polycondensation reaction for 3 hours at 180℃ and 20Pa vacuum to prepare 2591g of polyoxalate product.

[0088] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 181298 g / mol, particle hue L value is 83.3, a value is -2.9, and b value is 6.8.

[0089] Example 9

[0090] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0091] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0092] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 28.8g of pentaerythritol glycidyl ether to the reactor, and carry out the final polycondensation reaction for 3 hours at a temperature of 170℃ and a vacuum of 20Pa to prepare 2397g of polyoxalate product.

[0093] Performance characterization results of polyoxalate: intrinsic viscosity is 2.9 dL / g, weight-average molecular weight Mw = 499852 g / mol, particle hue L value is 85.8, a value is -3.8, and b value is 3.9.

[0094] Example 10

[0095] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of zinc oxalate dihydrate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0096] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0097] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of 1,2,6-hexanetriol to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2689g of polyoxalate product.

[0098] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 153102 g / mol, particle hue L value is 84, a value is -3.1, and b value is 8.9.

[0099] Example 11

[0100] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of tin oxalate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0101] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0102] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of 1,2,3-heptatriol to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2698g of polyoxalate product.

[0103] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 159301 g / mol, particle hue L value is 83.2, a value is -2.9, and b value is 7.1.

[0104] Example 12

[0105] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of nano-tin dioxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and 130℃ to obtain the low molecular weight esterified product.

[0106] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0107] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of glycerol triglycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2652g of polyoxalate product.

[0108] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 169810 g / mol, particle hue L value is 83.5, a value is -3.0, and b value is 7.2.

[0109] Example 13

[0110] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of bis(tri-n-butyltin) oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0111] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0112] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of ethoxylated glycerol triacrylate to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2616g of polyoxalate product.

[0113] Performance characterization results of polyoxalate: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 163642 g / mol, particle hue L value is 82.9, a value is -2.8, and b value is 7.0.

[0114] Example 14

[0115] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of zinc hydroxystannate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0116] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0117] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of tripropionic acid glyceride to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2715g of polyoxalate product.

[0118] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 163325 g / mol, particle hue L value is 83.9, a value is -3.1, and b value is 6.5.

[0119] Example 15

[0120] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of butylstannic acid and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0121] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0122] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of dipentaerythritol to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2731g of polyoxalate product.

[0123] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 156965 g / mol, particle hue L value is 82.1, a value is -2.6, and b value is 7.9.

[0124] Example 16

[0125] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of tert-butoxytin and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0126] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0127] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of pentaerythritol propionate to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2789g of polyoxalate product.

[0128] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 136555 g / mol, particle hue L value is 83.2, a value is -3.0, and b value is 7.8.

[0129] Example 17

[0130] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of dibutyltin dilaurate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0131] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0132] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of pentaerythritol triallyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2659g of polyoxalate product.

[0133] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 165992 g / mol, particle hue L value is 82.5, a value is -2.8, and b value is 7.9.

[0134] Example 18

[0135] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0136] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0137] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of pentaerythritol triacrylate to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2810g of polyoxalate product.

[0138] The performance characterization results of polyoxalate are as follows: intrinsic viscosity is 1.0 dL / g, weight-average molecular weight Mw = 145681 g / mol, particle hue L value is 82.4, a value is -2.8, and b value is 8.0.

[0139] Example 19

[0140] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0141] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0142] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of bis(2-hydroxyethyl)amino(trihydroxymethyl)methane to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2795g of polyoxalate product.

[0143] Performance characterization results of polyoxalate: intrinsic viscosity is 1.0 dL / g, weight-average molecular weight Mw = 136545 g / mol, particle hue L value is 83.1, a value is -3.1, and b value is 6.8.

[0144] Example 20

[0145] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0146] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0147] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of N-tris(hydroxymethyl)methacrylamide to the reactor, and carry out the final polycondensation reaction for 2 hours at 180°C and 20Pa vacuum to prepare 2835g of polyoxalate product.

[0148] Performance characterization results of polyoxalate: intrinsic viscosity is 0.9 dL / g, weight-average molecular weight Mw = 123541 g / mol, particle hue L value is 81.9, a value is -2.6, and b value is 9.5.

[0149] Example 21

[0150] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0151] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0152] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of methyl 2,3-epoxypropionate to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2835g of polyoxarate product.

[0153] Performance characterization results of polyoxalate: intrinsic viscosity is 0.9 dL / g, weight-average molecular weight Mw = 133854 g / mol, particle hue L value is 82.6, a value is -2.5, and b value is 9.2.

[0154] Example 22

[0155] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0156] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0157] Step (3) Final polycondensation stage: Add 1.044g of tri-o-toluene phosphite, 1.152g of antioxidant 1024 and 1.44g of allyl-2,3-epoxypropyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2735g of polyoxalate product.

[0158] Performance characterization results of polyoxalate: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 169877 g / mol, particle hue L value is 82.3, a value is -2.5, and b value is 9.6.

[0159] Example 23

[0160] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0161] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0162] Step (3) Final polycondensation stage: 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of diglycidyl 4,5-epoxytetrahydrophthalic acid were added to the reactor and the final polycondensation reaction was carried out at 180℃ and 20Pa vacuum for 2 hours to prepare 2719g of polyoxarate product.

[0163] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 135869 g / mol, particle hue L value is 82.7, a value is -2.5, and b value is 9.2.

[0164] Example 24

[0165] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0166] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0167] Step (3) Final polycondensation stage: 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of 1,4-cyclohexanediethanol bis(3,4-epoxycyclohexanecarboxylic acid) ester were added to the reactor, and the final polycondensation reaction was carried out at 180℃ and 20Pa vacuum for 2 hours to prepare 2739g of polyoxarate product.

[0168] Performance characterization results of polyoxalate: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 136857 g / mol, particle hue L value is 82.6, a value is -2.6, and b value is 9.0.

[0169] Example 25

[0170] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of zinc oxalate dihydrate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0171] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0172] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of neopentyl glycol diglycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2739g of polyoxalate product.

[0173] Performance characterization results of polyoxalate: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 166587 g / mol, particle hue L value is 83.0, a value is -2.8, and b value is 9.1.

[0174] Example 26

[0175] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of tin oxalate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0176] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0177] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of D-sorbitol diglycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2681g of polyoxalate product.

[0178] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.1 dL / g, weight-average molecular weight Mw = 132657 g / mol, particle hue L value is 83.1, a value is -2.9, and b value is 8.8.

[0179] Example 27

[0180] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of nano-tin dioxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and 130℃ to obtain the low molecular weight esterified product.

[0181] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0182] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of resorcinol diglycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2791g of polyoxalate product.

[0183] Performance characterization results of polyoxalate: intrinsic viscosity is 1.0 dL / g, weight-average molecular weight Mw = 133585 g / mol, particle hue L value is 83.4, a value is -3.1, and b value is 8.1.

[0184] Example 28

[0185] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of bis(tri-n-butyltin) oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0186] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0187] Step (3) Final polycondensation stage: 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of 1,4-butanediol diglycidyl ether were added to the reactor and the final polycondensation reaction was carried out at 180℃ and 20Pa vacuum for 2 hours to prepare 2759g of polyoxalate product.

[0188] Performance characterization results of polyoxalate: intrinsic viscosity is 0.9 dL / g, weight-average molecular weight Mw = 126584 g / mol, particle hue L value is 82.9, a value is -2.9, and b value is 8.9.

[0189] Example 29

[0190] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0191] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0192] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of 1,2-cyclohexanediol diglycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2721g of polyoxalate product.

[0193] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.0 dL / g, weight-average molecular weight Mw = 136398 g / mol, particle hue L value is 82.5, a value is -2.6, and b value is 8.4.

[0194] Example 30

[0195] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0196] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0197] Step (3) Final polycondensation stage: 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of triglycidyl-p-aminophenol were added to the reactor and the final polycondensation reaction was carried out at 180℃ and 20Pa vacuum for 2 hours to prepare 2621g of polyoxalate product.

[0198] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 1.4 dL / g, weight-average molecular weight Mw = 199852 g / mol, particle hue L value is 82.6, a value is -2.5, and b value is 8.5.

[0199] Example 31

[0200] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0201] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0202] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2659g of polyoxarate product.

[0203] Performance characterization results of polyoxalate: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 158952 g / mol, particle hue L value is 82.8, a value is -2.5, and b value is 8.4.

[0204] Example 32

[0205] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0206] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0207] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of diglycidyl tetrahydrophthalate to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2636g of polyoxalate product.

[0208] Performance characterization results of polyoxalate: intrinsic viscosity is 1.5 dL / g, weight-average molecular weight Mw = 198522 g / mol, particle hue L value is 82.9, a value is -2.5, and b value is 8.4.

[0209] Example 33

[0210] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0211] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0212] Step (3) Final polycondensation stage: 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarbamate were added to the reactor and the final polycondensation reaction was carried out at 180℃ and 20Pa vacuum for 2 hours to prepare 2728g of polyoxamate product.

[0213] Performance characterization results of polyoxalate: intrinsic viscosity is 0.9 dL / g, weight-average molecular weight Mw = 123968 g / mol, particle hue L value is 83.6, a value is -3.4, and b value is 6.9.

[0214] Example 34

[0215] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0216] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0217] Step (3) Final polycondensation stage: 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of bis(3,4-epoxycyclohexylmethyl) adipate were added to the reactor and the final polycondensation reaction was carried out at 180℃ and 20Pa vacuum for 2 hours to prepare 2713g of polyoxarate product.

[0218] Performance characterization results of polyoxalate: intrinsic viscosity is 1.3 dL / g, weight-average molecular weight Mw = 166882 g / mol, particle hue L value is 83.7, a value is -3.4, and b value is 6.8.

[0219] Example 35

[0220] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1800g (20mol) of 1,4-butanediol, and 0.288g of monobutyltin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0221] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0222] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 618 and 1.44g of diglycidyl hexahydrophthalic acid to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2702g of polyoxalate product.

[0223] Performance characterization results of polyoxalate: intrinsic viscosity is 1.2 dL / g, weight-average molecular weight Mw = 156882 g / mol, particle hue L value is 83.5, a value is -3.3, and b value is 6.9.

[0224] Comparative Example 1

[0225] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0226] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0227] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate and 1.152g of antioxidant 1010 to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2518g of polyoxarate product.

[0228] The performance characterization results of polyoxalate are as follows: intrinsic viscosity is 0.5 dL / g, weight-average molecular weight Mw = 100456 g / mol, particle hue L value is 84.8, a value is -3.8, and b value is 2.5.

[0229] Comparative Example 2

[0230] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of dimethyl tin oxide and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under a nitrogen atmosphere and at 130℃ to obtain a low molecular weight esterified product.

[0231] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0232] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate and 1.152g of antioxidant 1010 to the reactor, and carry out the final polycondensation reaction for 2 hours at a temperature of 190℃ and a vacuum of 20Pa to prepare 2518g of polyoxarate product.

[0233] Performance characterization results of polyoxalate: intrinsic viscosity is 1.0 dL / g, weight-average molecular weight Mw = 195892 g / mol, particle hue L value is 82.1, a value is -1.2, and b value is 10.5.

[0234] Comparative Example 3

[0235] Step (1) Esterification stage: Weigh 2360g (20mol) of dimethyl oxalate, 1240g (20mol) of ethylene glycol, and 0.288g of tetrabutyl titanate and add them to the reaction vessel. Then, carry out the esterification reaction for 3 hours under nitrogen atmosphere and at 130℃ to obtain the low molecular weight esterified product.

[0236] Step (2) Pre-condensation stage: The esterified product obtained in the transesterification stage is subjected to a pre-condensation reaction at a temperature of 130℃ and a vacuum of 2kPa for 1h.

[0237] Step (3) Final polycondensation stage: Add 1.044g of trimethylolpropionate phosphate, 1.152g of antioxidant 1010 and 1.44g of pentaerythritol glycidyl ether to the reactor, and carry out the final polycondensation reaction for 2 hours at 180℃ and 20Pa vacuum to prepare 2691g of polyoxarate product.

[0238] The performance characteristics of polyoxalate are as follows: intrinsic viscosity is 0.6 dL / g, weight-average molecular weight Mw = 105325 g / mol, particle hue L value is 80, a value is -0.8, and b value is 14.

[0239] Compared to Examples 1 to 35 of the present invention, no accelerator was used in Comparative Example 1, and the final polycondensation was carried out at a lower temperature. Although the color was better, the molecular weight was lower. In Comparative Example 2, no accelerator was added either. In order to obtain a high molecular weight, the reaction temperature was increased, but the color deteriorated.

Claims

1. A polyoxalate comprising structural units derived from oxalic acid and structural units derived from diols, The polyoxalate has a weight-average molecular weight of 120,000 to 1,000,000 g / mol, preferably 150,000 to 500,000 g / mol; The color of the polyoxalate was determined according to Method B of the Test Method for Colorimetry in GB / T14190-2008, with a colorimetry L value of 80 to 86, a value of -4 to -2.0, and a b value of 1.5 to 10.

2. The polyoxalate according to claim 1, wherein, The intrinsic viscosity of the polyoxalate was determined according to Method A of the test method for intrinsic viscosity in GB / T 14190-2008, and / or the intrinsic viscosity was 0.5–4.0 dL / g; and / or The diol is selected from at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,4-pentanediol, neopentanediol, cyclohexanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 1,2-heptanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,2-nonanediol, 1,9-nonanediol, 1,2-decanediol, naphth-1,8-diol, 3-methyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methyl-1,3-propanediol, 2-phenyl-1,3-propanediol, 1-phenyl-1,2-ethylenediol, 2-ethyl-1,3-hexanediol, and isosorbide.

3. A method for preparing polyoxalate, the method comprising the following steps: (1) Transesterification stage: Oxalic acid or oxalate diester, diol and catalyst are added to the reaction vessel; Then, an esterification reaction was carried out under an inert atmosphere and heating conditions to obtain a low molecular weight esterified product. (2) Pre-polymerization stage: The low molecular weight ester obtained in step (1) is subjected to pre-polymerization reaction under heating and vacuum conditions to further increase the molecular weight; (3) Final polycondensation stage: Heat stabilizer, antioxidant and accelerator are added to the reactor and the final polycondensation reaction is carried out at a temperature of 150-190°C, preferably 160-190°C and under vacuum to obtain polyoxalate product. The accelerator is an epoxy compound, a polyol containing three or more hydroxyl groups, or an ether or ester derived from the epoxy compound or polyol.

4. The method for preparing polyoxalate according to claim 3, wherein, The accelerator is selected from 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,3-heptanetriol, glycerol triglycidyl ether, ethoxylated glycerol triacrylate, 2-methyl-1,2,3-propanetriol, tripropionate, dipentapentyl alcohol, tripentapentyl alcohol, pentaerythritol glycidyl ether, pentaerythritol propionate, pentaerythritol triallyl ether, pentaerythritol triacrylate, bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane), N-tris(hydroxymethyl)methacrylamide, methyl 2,3-epoxypropionate, allyl-2,3-epoxypropyl ether, 4,5-epoxytetrahydrophthalic acid diglycidyl ether, 1,4-cyclohexanediol dimethyl ether. At least one of the following: (3,4-epoxycyclohexanecarboxylic acid) ester, neopentyl glycol diglycidyl ether, D-sorbitol diglycidyl ether, resorcinol diglycidyl ether, diethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl p-aminophenol, 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylic acid ester, bis(3,4-epoxycyclohexylmethyl) adipate, and hexahydrophthalic acid diglycidyl ester.

5. The method for preparing polyoxalate according to claim 3 or 4, wherein, The oxalate diester is at least one selected from dimethyl oxalate, diethyl oxalate, dipropyl oxalate, and dibutyl oxalate, preferably dimethyl oxalate and / or diethyl oxalate; and / or The diol is selected from at least one of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,4-pentanediol, neopentanediol, cyclohexanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 1,2-heptanediol, 1,7-heptanediol, 1,8-octanediol, 1,2-octanediol, 1,2-nonanediol, 1,9-nonanediol, 1,2-decanediol, naphth-1,8-diol, 3-methyl-1,5-pentanediol, 3-methyl-1,3-butanediol, 2-methyl-1,3-propanediol, 2-phenyl-1,3-propanediol, 1-phenyl-1,2-ethylenediol, 2-ethyl-1,3-hexanediol, and isosorbide.

6. The method for preparing polyoxalate according to any one of claims 3 to 5, wherein, In step (1), the molar ratio of the oxalate diester and / or oxalic acid to the diol is between 0.5:1 and 2:1, preferably between 0.9:1 and 1.2:1; and / or The catalyst is selected from at least one of zinc oxalate dihydrate, tin oxalate, nano tin dioxide, bis(tri-n-butyltin) oxide, zinc hydroxystannate, monobutyltin oxide, butylstannic acid, tert-butoxytin, dimethyltin oxide, and dibutyltin dilaurate, preferably one or two of dimethyltin oxide and monobutyltin oxide.

7. The method for preparing polyoxalate according to any one of claims 3 to 6, wherein, In step (1), the amount of catalyst used is 1 / 100,000 to 1 / 200 of the mass of the polyoxalate product, preferably 1 / 10,000 to 1 / 5,000; and / or The esterification reaction in step (1) is carried out at a temperature of 100–140°C, preferably 110–130°C; and / or The reaction time for the esterification reaction in step (1) is 1 to 4 hours, preferably 2 to 3 hours.

8. The method for preparing polyoxalate according to any one of claims 3 to 7, wherein, The reaction temperature of the pre-condensation reaction in step (2) is 100–140°C, preferably 110–130°C; and / or The vacuum degree of the pre-condensation reaction in step (2) is 1-100 kPa, preferably 2-10 kPa; and / or The reaction time for the pre-condensation reaction in step (2) is 0.5 to 3 hours, preferably 1 to 2 hours.

9. The method for preparing polyoxalate according to any one of claims 3 to 8, wherein, The vacuum degree of the final polycondensation reaction in step (3) is 0.1–200 Pa, preferably 2–20 Pa; and / or The reaction time for the final polycondensation reaction in step (3) is 1 to 4 hours, preferably 2 to 3 hours; and / or The heat stabilizer is selected from at least one of didecyl phosphate, dibenzyl phosphate, octadecyl phosphate, tripentyl phosphate, trioctyl phosphate, triisobutyl phosphate, tri-m-toluene phosphate, tri-o-toluene phosphate, dibenzyl phosphite, di-tert-butyl phosphite, diisopropyl phosphite, diisobutyl phosphite, phenyl diisooctyl phosphite, trihexyl phosphite, trinepentyl phosphite, triisodecyl phosphite, and tri-o-toluene phosphite, preferably one or two of tri-m-toluene phosphate and tri-o-toluene phosphite.

10. The method for preparing polyoxalate according to any one of claims 3 to 9, wherein, The amount of the heat stabilizer is 1 / 10000 to 1 / 100 of the mass of the polyoxalate product, preferably 1 / 10000 to 1 / 1000; and / or The antioxidant is selected from at least one of antioxidant 618, antioxidant 565, antioxidant 264, antioxidant 300, antioxidant 702, antioxidant 136, antioxidant 1098, antioxidant 1024, antioxidant 697, antioxidant 1135, antioxidant 5057, antioxidant 702, antioxidant 330, antioxidant 3114, antioxidant 1035, antioxidant 1425, and antioxidant 2246, more preferably one or both of antioxidant 618 and antioxidant 1024; and / or The amount of the antioxidant is 1 / 10000 to 1 / 100 of the mass of the polyoxalate product, preferably 1 / 10000 to 1 / 1000; and / or The amount of the accelerator used is 1 / 10000 to 1 / 100 of the mass of the polyoxalate product, preferably 1 / 10000 to 1 / 1000.

11. Use of an accelerator in the preparation of polyoxalate, wherein the accelerator is an epoxy compound, a polyol containing three hydroxyl groups, or an ether or ester derived from said epoxy compound or polyol. Preferably, the accelerator is selected from 1,2,4-butanetriol, 1,2,6-hexanetriol, 1,2,3-heptanetriol, glycerol triglycidyl ether, ethoxylated glycerol triacrylate, 2-methyl-1,2,3-propanetriol, triglyceride tripropionate, dipentapentanol, tripentapentanol, pentaerythritol glycidyl ether, pentaerythritol propionate, pentaerythritol triallyl ether, pentaerythritol triacrylate, bis(2-hydroxyethyl)amino(tris(hydroxymethyl)methane), N-tris(hydroxymethyl)methacrylamide, methyl 2,3-epoxypropionate, allyl-2,3-epoxypropyl ether, 4,5-epoxytetrahydrophthalic acid diglycidyl ether, 1,4-cyclohexanediol, etc. The following is a list of at least one of the following: bis(3,4-epoxycyclohexanecarboxylic acid) ester, neopentyl glycol diglycidyl ether, D-sorbitol diglycidyl ether, resorcinol diglycidyl ether, diethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl p-aminophenol, 4,5-epoxycyclohexane-1,2-dicarboxylic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexylcarboxylic acid ester, bis(3,4-epoxycyclohexylmethyl) adipate, and hexahydrophthalic acid diglycidyl ester.