阅读说明：本技术 一种生物降解周期可控的地膜树脂及其制备方法 (Mulching film resin with controllable biodegradation period and preparation method thereof ) 是由 东为富 袁皓 王世波 张正 吴杰 李婷 汪洋 于 2020-07-07 设计创作，主要内容包括：一种生物降解周期可控的地膜树脂及其制备方法,属于高分子量地膜树脂领域。所述的地膜树脂的聚合单体包括：A：脂肪族二元酸及其酸酐、二酯、二酰卤中的一种或两种以上混合；B：不饱和脂肪酸及其多聚体、酸酐、酰卤中的一种或两种以上混合；C：芳香族二元酸及其酸酐、二酯、二酰卤中的一种或两种以上混合；D：脂肪族二元醇中的一种或两种以上混合；E：异氰酸酯、碳化二亚胺、环氧化合物类扩链剂中的一种或两种以上混合。所述的地膜树脂由上述聚合单体A、B、C与D在催化剂条件下进行酯化,再通过熔融缩聚或界面聚合,最后经过熔融扩链反应制备得到。本发明的地膜树脂分子量高、机械性能优异,且可通过调整单体比例来调控材料降解周期。(A mulching film resin with controllable biodegradation period and a preparation method thereof belong to the field of high molecular weight mulching film resin. The polymerization monomer of the mulching film resin comprises: a: one or more than two of aliphatic dibasic acid and anhydride, diester and diacid halide thereof are mixed; b: unsaturated fatty acid and its polymer, acid anhydride, acyl halide or a mixture of two or more of them; c: mixing aromatic diacid and one or more than two of anhydride, diester and diacid halide thereof; d: one or more than two of aliphatic dihydric alcohol are mixed; e: one or more than two of isocyanate, carbodiimide and epoxy compound chain extender. The mulching film resin is prepared by esterifying the polymerized monomer A, B, C and D under the condition of a catalyst, performing melt polycondensation or interfacial polymerization, and finally performing melt chain extension reaction. The mulching film resin disclosed by the invention is high in molecular weight and excellent in mechanical property, and the degradation period of the material can be regulated and controlled by adjusting the monomer proportion.)

1. the mulching film resin with controllable biodegradation period is characterized in that polymerized monomers of the mulching film resin comprise:

a: one or more than two of aliphatic dibasic acid and anhydride, diester and diacid halide thereof are mixed;

b: unsaturated fatty acid and its polymer, acid anhydride, acyl halide or a mixture of two or more of them;

c: mixing aromatic diacid and one or more than two of anhydride, diester and diacid halide thereof;

d: one or more than two of aliphatic dihydric alcohol are mixed;

e: one or more than two of isocyanate, carbodiimide and epoxy compound chain extenders are mixed;

the mulching film resin is prepared by esterifying the polymerized monomer A, B, C and D under the condition of a catalyst, performing melt polycondensation or interfacial polymerization, and finally performing melt chain extension reaction.

2. The mulching film resin with the controllable biodegradation period according to claim 1, wherein the molar ratio of the sum of the functional groups of the polymerized monomer A, B, C to the functional groups of the polymerized monomer D is 1: 1-2; the molar ratio of the polymerized monomer C to the total polymerized monomer A, B, C is below 60%, and the addition amount of the chain extender E is below 10% of the total polymerized monomer by mass percent.

3. The mulching film resin with the controllable biodegradation period according to claim 1, wherein the number average molecular weight of the mulching film resin is 40000-70000 g/mol, and the molecular weight distribution is 1.5-3; the melt index of the mulching film resin is 3-5 g/10min, and the terminal carboxyl is 5-20 mol/t.

4. The mulching film resin with controllable biodegradation period according to claim 1, wherein the polymerized monomer A is one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, and anhydrides, diesters and dihalide derivatives thereof.

5. The mulch resin according to claim 1, wherein the polymeric monomer B is one or more of oleic acid, linoleic acid, linolenic acid, arachidonic acid, 20-C-5-enoic acid, 22-C-6-enoic acid and its polymer, anhydride, and acyl halide derivatives.

6. The mulch resin according to claim 1, wherein the polymeric monomer C is one or a mixture of two or more of terephthalic acid, phthalic acid, isophthalic acid, 1, 4-naphthalene dicarboxylic acid, 2, 6-naphthalene dicarboxylic acid, 2, 3-naphthalene dicarboxylic acid, 1, 8-naphthalene dicarboxylic acid and their anhydrides, diesters, and dihalide derivatives.

7. The mulching film resin with controllable biodegradation period according to claim 1, wherein the polymerized monomer D is ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 4-butanediol, 1, 3-butanediol, 1, 2-butanediol, 2-methyl-1, 3-propanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 2, 4-diethyl-1, 5-pentanediol, 2, 4-trimethyl-1, 3-pentanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2-ethyl-1, 3-hexanediol, 1, 7-heptanediol, heptanediol, 1, 8-octanediol, 2-methyl-1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, polyoxyethylene, polyethylene glycol, and polypropylene glycol.

8. The mulch resin with controllable biodegradation period according to claim 1, wherein, the polymerization monomer E is one or a mixture of more than two of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, dicyclohexylcarbodiimide, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1, 4-butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, furan methyl glycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, bisphenol A diglycidyl ether and resorcinol diglycidyl ether.

9. A preparation method of mulching film resin with controllable biodegradation period is characterized by comprising the following steps:

(1) uniformly mixing the polymerized monomers A, B, C, D, adding 0.01-0.5% of catalyst by mass percent for esterification reaction, and completing the esterification stage when a collection system is not generated with water;

(2) then, performing polycondensation reaction, and finishing the polycondensation reaction when the melt index of the material is increased to 15-50 g/10 min;

(3) and (3) finally, carrying out chain extension reaction, and adding a polymerization monomer E after the step (2) to carry out melt chain extension reaction at the temperature of 150-230 ℃.

10. The preparation method of claim 9, wherein the esterification reaction temperature is 200-260 ℃ and the esterification reaction time is 1-3 h; the temperature of the polycondensation reaction is 230-250 ℃, the vacuum degree of the polycondensation reaction is 20-4000 pa, and the polycondensation reaction time is 2-5 h; carrying out a melt chain extension reaction at 150-230 ℃; the reaction catalyst in the step (1) is one or more of Lewis acid, germanium compounds, antimony compounds, titanium compounds, zinc compounds and tin compounds.

Technical Field

The invention relates to a mulching film resin with a controllable biodegradation period and a preparation method thereof, in particular to a high-molecular-weight mulching film resin with a controllable biodegradation period and a preparation method thereof.

Background

The mulching technology brings great economic benefits to agriculture in China since the introduction of 20 th century and 70 th era into China. Meanwhile, the mulching film is difficult to recycle, so that the pollution of the residual mulching film is caused, and the problem seriously influences the agricultural sustainable development strategy of China. The most effective way for solving the residual pollution of the mulching film is to develop a biodegradable mulching film, and the biodegradable mulching film can be completely degraded into carbon dioxide and water under natural conditions, so that the soil cannot be polluted.

The commercial biodegradable mulching film resin is one or more of poly (terephthalic acid-butylene adipate) ester (PBAT), poly (butylene succinate) (PBS), poly (butylene succinate-adipate-butylene succinate) (PBSA) and poly (lactic acid) (PLA), and the degradation period of the biodegradable mulching film resin is too fast under natural conditions and cannot meet the long-period soil moisture preservation and water retention requirements of crops, so that the degradation period of the biodegradable mulching film is regulated by adding auxiliary agents such as an antioxidant, an ultraviolet absorbent, an ultraviolet stabilizer and the like or by processing technology such as multilayer co-extrusion and the like. The publication No. CN103665784A adopts aromatic-aliphatic copolyester, polylactic acid and starch-based biodegradable materials, and adds ultraviolet light stabilizer and antioxidant to realize the biodegradation controllability of the mulching film; the publication No. CN104072953A realizes controllable degradation of the mulching film by compounding flexibility and rigid biodegradable resin and adding functional auxiliaries such as an ultraviolet light stabilizer, an ultraviolet absorbent, an antioxidant, an anti-hydrolysis agent, a chain extender and the like; the publication No. CN104559087A solves the problem of the degradation period of the mulching film by regulating the proportion of polylactic acid and poly (terephthalic acid) -adipic acid-butanediol ester and adding a reactive auxiliary agent, an antioxidant, a lubricant, an ultraviolet absorbent and a light stabilizer; the publication No. CN109679299A uses PBAT as raw material, and adds degradation rate regulator and induction period regulator to achieve the purpose of controllable degradation. In the patents, light stabilizers, ultraviolet absorbers and other auxiliaries are used, so that the cost is high, and soil microorganisms are influenced. The publication numbers CN103587184A and CN105109165A both adopt a multilayer co-extrusion processing technology to ensure that the mulching film meets the controllable degradation requirement.

In summary, the existing biodegradable mulching film is mainly prepared by compounding PBAT and PLA, and adding light stabilizer, ultraviolet absorbent, antioxidant and other auxiliaries to regulate and control the degradation period of the mulching film, and the technologies for preparing the mulching film have high cost and influence on soil microorganisms.

Disclosure of Invention

The term "biodegradable mulching film" refers to a mulching film which is completely converted into carbon dioxide and water by soil microorganisms under natural conditions of illumination, moisture and the like.

Aiming at the problems in the prior art, the invention has the advantage that the biodegradable mulching film with high molecular weight, controllable biodegradation period and excellent mechanical property is prepared by adopting a one-step method.

The technical scheme for preparing the biodegradable mulching film resin with the controllable period is as follows:

a mulch resin with controllable biodegradation period, wherein the polymerized monomers of the mulch resin comprise:

a: one or more than two of aliphatic dibasic acid and anhydride, diester and diacid halide thereof are mixed;

b: unsaturated fatty acid and its polymer, acid anhydride, acyl halide or a mixture of two or more of them;

c: mixing aromatic diacid and one or more than two of anhydride, diester and diacid halide thereof;

d: one or more than two of aliphatic dihydric alcohol are mixed;

e: one or more than two of isocyanate, carbodiimide and epoxy compound chain extender.

The mulching film resin is prepared by esterifying the polymerized monomer A, B, C and D under the condition of a catalyst, performing melt polycondensation or interfacial polymerization, and finally performing melt chain extension reaction.

The molar ratio of the sum of the functional groups of the polymerized monomer A, B, C to the functional group of the polymerized monomer D is 1: 1-2;

the molar ratio of the polymerized monomer C to the total polymerized monomer A, B, C is less than 60%;

the addition amount of the chain extender E accounts for less than 10 percent of the total polymerized monomers by mass.

The number average molecular weight of the mulching film resin is 40000-70000 g/mol, and the molecular weight distribution is 1.5-3;

the melt index of the mulching film resin is 3-5 g/10min, and the terminal carboxyl is 5-20 mol/t.

The polymerization monomer A is one or the mixture of more than two of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid and anhydride, diester and diacid halide derivatives thereof.

The polymeric monomer B is one or more of oleic acid, linoleic acid, linolenic acid, arachidonic acid, 20-carbon-5-olefine acid, 22-carbon-6-olefine acid and polymer thereof, acid anhydride and acyl halide derivatives.

The polymerization monomer C is one or the mixture of more than two of terephthalic acid, phthalic acid, isophthalic acid, 1, 4-naphthalene dicarboxylic acid, 2, 6-naphthalene dicarboxylic acid, 2, 3-naphthalene dicarboxylic acid, 1, 8-naphthalene dicarboxylic acid and anhydride, diester and dihalide derivatives thereof.

The polymerization monomer D is ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 1, 4-butanediol, 1, 3-butanediol, 1, 2-butanediol, 2-methyl-1, 3-propanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 3-methyl-1, 5-pentanediol, 2, 4-diethyl-1, 5-pentanediol, 2, 4-trimethyl-1, 3-pentanediol, 2-butyl-2-ethyl-1, 3-propanediol, 2-ethyl-1, 3-hexanediol, 1, 7-heptanediol, 1, 8-octanediol, 2-methyl-1, 8-octanediol, 1, 3-octanediol, 2-methyl-1, 8-octanediol, or mixtures thereof, 1, 9-nonanediol, 1, 10-decanediol, polyoxyethylene, polyethylene glycol and polypropylene glycol.

The polymerization monomer E is one or a mixture of more than two of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, dicyclohexylcarbodiimide, 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1, 4-butanediol diglycidyl ether, trimethylolpropane triglycidyl ether, furan methyl glycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, bisphenol A diglycidyl ether and resorcinol diglycidyl ether.

A preparation method of mulching film resin with controllable biodegradation period comprises the following steps:

(1) uniformly mixing the polymerized monomers A, B, C, D, adding 0.01-0.5% of catalyst by mass percent for esterification reaction, and completing the esterification stage when the collection system is not generated with water;

(2) then, performing polycondensation reaction, and finishing the polycondensation reaction when the melt index of the material is increased to 15-50 g/10 min;

(3) and (3) finally, carrying out chain extension reaction, and adding a polymerization monomer E to carry out melt chain extension reaction after the step (2).

The esterification reaction temperature of the step (1) is 200-260 ℃, and the esterification reaction time is 1-3 h;

the reaction catalyst in the step (1) is one or more of Lewis acid, germanium compounds, antimony compounds, titanium compounds, zinc compounds and tin compounds.

The temperature of the polycondensation reaction in the step (2) is 230-250 ℃, the vacuum degree of the polycondensation reaction is 20-4000 pa, and the polycondensation reaction time is 2-5 h;

the temperature of the melting chain extension reaction in the step (3) is 150-230 ℃.

Compared with the prior art, the invention has the beneficial effects that:

(1) the prepared biodegradable plastic film resin polymerization monomers with controllable period are all large industrialized commodities and are low in price;

(2) the biodegradable cycle controllable mulching film resin prepared by the invention has high molecular weight and excellent mechanical property, and the degradation cycle of the material can be regulated and controlled by adjusting the proportion of the monomers;

(3) the polymerization process is simple, the industrial production can be realized, and the prepared mulching film resin with the controllable biodegradation period has excellent and stable quality.

Detailed Description

The present invention is further described below with reference to examples, but the scope of the present invention is not limited by these examples. The scope of the invention is set forth in the claims.

The molecular weight and the molecular weight distribution of the polymer are determined by adopting a gel permeation chromatography, chloroform is used as a solvent, a Waters-1525u instrument is used for testing, and polystyrene is used as a standard sample.

The carboxyl end groups of the polymer are tested by an acid-base titration method according to the method A in GB/T14190-. The mixed solution is phenol-trichloromethane with the volume ratio of 2: 3. The standard titration solution is potassium hydroxide-benzyl alcohol, the concentration is 0.01mol/L, and the standard titration solution is configured and calibrated according to 4.24 in GB/T601-2002. The bromophenol blue indicator concentration was 0.2%. Test preparation: 0.5g of the sample was dissolved in 25.00ml of a phenol-chloroform mixed solvent.

The melt index of the polymer was measured by a melt index meter according to GB/T3682-2000 rule A under test conditions D (temperature: 190 ℃ C., load 2.16 kg).

Tensile properties of the polymers were tested according to GB/T17037.1-1997, using the type A abrasive tool of GB/T17037.1-1997 to prepare specimens conforming to type 1A of GB/T1040.2-2006. The conditioning of the sample is carried out according to the regulations GB/T2918-. The test was carried out as specified in GB/T1040.2-2006, with a test rate of 50 mm/min.