阅读说明：本技术 一种高淀粉含量吹膜复合材料及其制备方法 (High-starch-content film blowing composite material and preparation method thereof ) 是由 吕沙峰 张剑锋 于 2019-11-13 设计创作，主要内容包括：本发明涉及生物降解复合材料技术领域,具体涉及一种高淀粉含量吹膜复合材料及其制备方法。一种高淀粉含量吹膜复合材料,包括以下重量份的原料：淀粉35-50份、低密度聚乙烯20-40份、环氧植物油增塑剂10-20份、内润滑剂0.5-2份、外润滑剂0.1-1份、偶联剂0.5-1份、相容剂3-10份、抗氧剂0.2-0.5份。本发明的高淀粉复合材料的淀粉含量高、成本低廉、组分相容性好,材料的力学性能、生物降解性能显著提高,具备可持续发展的优良特性,可以在通用的塑料加工设备上采用模压、挤出、注塑等工艺加工成制品。(The invention relates to the technical field of biodegradable composite materials, in particular to a high-starch-content blown film composite material and a preparation method thereof. A high-starch-content blown film composite material comprises the following raw materials in parts by weight: 35-50 parts of starch, 20-40 parts of low-density polyethylene, 10-20 parts of epoxy vegetable oil plasticizer, 0.5-2 parts of internal lubricant, 0.1-1 part of external lubricant, 0.5-1 part of coupling agent, 3-10 parts of compatilizer and 0.2-0.5 part of antioxidant. The high-starch composite material has the advantages of high starch content, low cost, good component compatibility, obviously improved mechanical property and biodegradability, and excellent characteristics of sustainable development, and can be processed into products on general plastic processing equipment by adopting processes of die pressing, extrusion, injection molding and the like.)

1. The high-starch-content blown film composite material is characterized by comprising the following raw materials in parts by weight: 35-50 parts of starch, 20-40 parts of low-density polyethylene, 10-20 parts of epoxy vegetable oil plasticizer, 0.5-2 parts of internal lubricant, 0.1-1 part of external lubricant, 0.5-1 part of coupling agent, 3-10 parts of compatilizer and 0.2-0.5 part of antioxidant.

2. The high starch content blown film composite of claim 1, wherein said starch is selected from the group consisting of corn starch, tapioca starch, mung bean starch, sweet potato starch, wheat starch, water chestnut starch, lotus root starch, and mixtures thereof.

3. The high starch content blown film composite of claim 2, wherein said starch is corn starch, said corn starch is high amylose corn starch, and the mass percentage of amylose in said high amylose corn starch is 40-70%.

4. The high starch content blown film composite of claim 3, wherein said high amylose corn starch is selected from one or more of acetylated high amylose corn starch, hydroxypropylated high amylose corn starch.

5. The high starch content blown film composite of claim 1, wherein said epoxidized vegetable oil plasticizer is selected from the group consisting of one or more blends of epoxidized soybean oil, epoxidized sunflower oil, epoxidized cottonseed oil, and epoxidized rice bran oil.

6. The high starch content blown film composite of claim 1, wherein said internal lubricant is selected from the group consisting of a blend of one or more of higher fatty alcohols, n-butyl stearate, glycerol trihydroxystearate.

7. The high starch content blown film composite of claim 1, wherein said external lubricant is selected from the group consisting of calcium stearate, zinc stearate, microcrystalline paraffin, stearic acid amide, oleic acid amide, erucic acid amide, polyethylene wax, and mixtures thereof.

8. The high starch content blown film composite of claim 1, wherein said compatibilizer is selected from the group consisting of maleic anhydride grafted ethylene-octene copolymer resin, maleic anhydride grafted polylactic acid resin, maleic anhydride grafted polyethylene copolymer resin, and mixtures thereof.

9. The blown film composite with high starch content according to claim 1, wherein the coupling agent is selected from one or more of silane coupling agent, aluminate, titanate and aluminum titanium composite coupling agent.

10. A method of making a high starch content blown film composite according to any one of claims 1 to 9, comprising the steps of: premixing and dehumidifying the raw materials, mixing at the rotating speed of 2000-3000rp and the temperature of 85-95 ℃, and then mixing at the rotating speed of 300-400rpm to obtain a mixed material; and stirring the mixed materials at room temperature, naturally cooling, melting, blending, extruding, and blowing for molding to obtain the product.

Technical Field

The invention belongs to the technical field of biodegradable composite materials, and particularly relates to a high-starch-content blown film composite material and a preparation method thereof.

Background

With the development of the plastic industry and the development of plastic varieties, more and more plastic products become indispensable materials in human lives. The traditional plastic is difficult to biodegrade, and the environment is seriously polluted by the large amount of piled plastic wastes.

The degradable plastics which are put into use at present are mainly starch plastics, the starch plastics have low starch content, generally 10-30%, and the rest main components are still high molecular components which are difficult to degrade. Chinese patent CN1478809A discloses a biodegradable starch resin master batch and a preparation method thereof, which comprises the steps of firstly preparing refined starch by a high-speed impact method, heating the refined starch in a high-speed mixer, adding a cross-linking agent to prepare refined modified starch, then cooling the refined modified starch, adding resin and polymer for granulation to obtain the starch resin master batch. It has the following disadvantages: firstly, starch is modified by a cross-linking agent, and the cross-linking degree is not easy to control; secondly, the starch and the cross-linking agent are subjected to cross-linking reaction, so that the obtained starch has good strength, but the treatment effect on the crystallization polarity and the reaction activity of the starch is poor; thirdly, the rotation degree of starch molecules is reduced due to steric effect through crosslinking reaction, the flexibility of the molecules is reduced, the rigidity is increased, and the brittleness of the product is larger. Chinese patent 93111901.4 discloses a biodegradable and photo-degradable plastic film, wherein modified starch is prepared by mixing starch with fatty acid or low molecular hydrocarbon to obtain hydrophobic starch, i.e. coating a layer of fatty acid or low molecular hydrocarbon on the surface of starch granules, in order to increase the compatibility with resin. The disadvantages are that the modified starch has poor processability and poor compatibility with resin, thus resulting in poor mechanical strength and rough appearance of film products, and low starch content in the master batch and the film products, thus having poor biodegradability.

Disclosure of Invention

In order to solve the problems, the invention provides a high-starch-content blown film composite material in a first aspect, which comprises the following raw materials in parts by weight: 35-50 parts of starch, 20-40 parts of low-density polyethylene, 10-20 parts of epoxy vegetable oil plasticizer, 0.5-2 parts of internal lubricant, 0.1-1 part of external lubricant, 0.5-1 part of coupling agent, 3-10 parts of compatilizer and 0.2-0.5 part of antioxidant.

As a preferable technical scheme, the starch is selected from one or more of corn starch, cassava starch, mung bean starch, sweet potato starch, wheat starch, water chestnut starch and lotus root starch.

As a preferable technical scheme, the starch is corn starch, the corn starch is high amylose corn starch, and the mass percentage of amylose in the high amylose corn starch is 40-70%.

As a preferred technical scheme, the high amylose corn starch is selected from one or more of acetylated high amylose corn starch, hydroxypropylated high amylose corn starch and hydroxypropyl acetylated high amylose corn starch.

As a preferred technical scheme, the epoxy vegetable oil plasticizer is selected from one or more of epoxy soybean oil, epoxy sunflower oil, epoxy cottonseed oil and epoxy rice bran oil.

As a preferable technical scheme, the internal lubricant is selected from one or more of higher fatty alcohol, n-butyl stearate and glycerol trihydroxy stearate.

As a preferred technical scheme, the external lubricant is selected from one or more of calcium stearate, zinc stearate, microcrystalline wax, stearic acid amide, oleic acid amide, erucic acid amide and polyethylene wax.

As a preferred technical scheme, the compatilizer is one or more selected from maleic anhydride grafted ethylene-octene copolymer resin, maleic anhydride grafted polylactic acid resin and maleic anhydride grafted polyethylene copolymer resin.

As a preferred technical scheme, the coupling agent is selected from one or more of silane coupling agent, aluminate, titanate and aluminum-titanium composite coupling agent.

As a preferred technical scheme, the antioxidant is one or a mixture of antioxidant 1010, antioxidant 1076, antioxidant 2246 or antioxidant BHT.

In a second aspect, the present invention provides a method for preparing a blown film composite with high starch content as described above, comprising the steps of: premixing and dehumidifying the raw materials, mixing at the rotating speed of 2000-3000rp and the temperature of 85-95 ℃, and then mixing at the rotating speed of 300-400rpm to obtain a mixed material; and stirring the mixed materials at room temperature, naturally cooling, melting, blending, extruding, and blowing for molding to obtain the product.

Has the advantages that: the high-starch composite material has the advantages of high starch content, low cost, good component compatibility, obviously improved mechanical property and biodegradability, and excellent characteristics of sustainable development, and can be processed into products on general plastic processing equipment by adopting processes of die pressing, extrusion, injection molding and the like.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "including". As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase will render the claim closed except for the materials described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein in the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received by modifying or otherwise modifying such quantity without substantially changing the basic function to which it is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

The invention provides a high-starch-content blown film composite material, which comprises the following raw materials in parts by weight: 35-50 parts of starch, 20-40 parts of low-density polyethylene, 10-20 parts of epoxy vegetable oil plasticizer, 0.5-2 parts of internal lubricant, 1.1-1 part of external lubricant, 0.5-1 part of coupling agent, 3-10 parts of compatilizer and 0.2-0.5 part of antioxidant.

Starch

The starch is polysaccharide formed by connecting dehydrated D-glucose serving as a repeating unit through glycosidic bondsA polymer compound having the formula (C)₆H₁₀O₅)_nAnd n is an indefinite number, which varies depending on the starch species. Starch is mainly composed of two different polymers, amylose and amylopectin, which have different molecular structures due to the presence of different glycosidic linkages.

In one embodiment, the starch is selected from the group consisting of corn starch, tapioca starch, mung bean starch, sweet potato starch, wheat starch, water chestnut starch, lotus root starch, and mixtures thereof.

In a preferred embodiment, the starch is corn starch.

In a preferred embodiment, the corn starch is a high amylose corn starch; the mass percentage of amylose in the high amylose corn starch is 40-70%.

In a preferred embodiment, the high amylose corn starch is selected from one or more of acetylated high amylose corn starch, hydroxypropylated high amylose corn starch.

In a preferred embodiment, the corn starch is hydroxypropyl acetylated high amylose corn starch.

In a preferred embodiment, the method for preparing hydroxypropyl acetylated high amylose corn starch comprises the steps of:

(1) dissolving high amylose corn starch in a sodium sulfate solution to prepare starch milk with the mass concentration of 35%, wherein the mass of sodium sulfate accounts for 10% of the mass of starch. And (3) carrying out constant-temperature water bath, stirring at a constant speed, slowly dropwise adding 1 wt% of sodium hydroxide solution to adjust the pH of the emulsion to 8.5, and then adding propylene oxide, wherein the mass of the propylene oxide accounts for 10% of that of the starch. Introducing nitrogen, sealing the container and reacting for 24 hours. After the reaction was completed, the pH was adjusted to 6.50 with a 1 wt% hydrochloric acid solution. Washing starch with water, washing with alcohol, drying, and sieving to obtain hydroxypropyl etherified starch;

(2) dissolving the hydroxypropyl etherified starch obtained in the step (1) in distilled water to obtain a hydroxypropyl etherified starch emulsion with the volume fraction of 40%, stirring for 1h at 25 ℃, adjusting the pH of the emulsion to 8.0 by using a 3 wt% sodium hydroxide solution, adding acetic anhydride, simultaneously keeping the pH of the emulsion constant by using a 3 wt% sodium hydroxide solution, reacting for 1.5h, adjusting the pH to 6.50 by using a 1 wt% hydrochloric acid solution, centrifuging, washing with water, washing with alcohol, drying at 40 ℃, and crushing to obtain the hydroxypropyl etherified starch emulsion.