阅读说明：本技术 一种可降解薄膜及制备方法 (Degradable film and preparation method thereof ) 是由 袁东平 于 2019-10-12 设计创作，主要内容包括：本发明公开了一种可降解薄膜,由以下原料制成：一种可降解薄膜,各组分以重量百分比计：PVA50%～60%、玉米淀粉20%～30%、甘油20%～30%、交联剂PLA2.5%～3%、填充改性剂甘蔗纤维20%～30%和纯化水870%～1000%,一种可降解薄膜的制备方法,包括以下步骤：A、浸泡：在蒸汽加热搅拌罐中加入PVA50%～60%、纯化水500%～600%搅拌均匀,静置后备用,本发明通过将小分子的填充改性剂甘蔗纤维填充入大分子的PVA和淀粉结构中,得到强度更高的PVA薄膜,增强薄膜的耐水能力,薄膜在浸水一段时间后仍保持一定强度和弹性,可以二次循环使用,在长时间浸水后最终水解破裂,降解过程迅速,减少废弃物的丢弃,分步加热、分步混合的做法使淀粉等有机原料不至于过热分解,影响交联。(The invention discloses a degradable film which is prepared from the following raw materials: a degradable film comprises the following components in percentage by weight: PVA50% -60%, corn starch 20% -30%, glycerin 20% -30%, cross-linking agent PLA2.5% -3%, filling modifier sugarcane fiber 20% -30% and purified water 870% -1000%, and a preparation method of the degradable film comprises the following steps: A. soaking: the method comprises the steps of adding 50-60% of PVA and 500-600% of purified water into a steam heating stirring tank, uniformly stirring, standing for later use, filling micromolecule filling modifier sugarcane fibers into macromolecular PVA and starch structures to obtain a PVA film with higher strength, enhancing the water resistance of the film, keeping certain strength and elasticity of the film after being soaked for a period of time, being capable of being recycled for the second time, finally hydrolyzing and breaking after being soaked for a long time, reducing the discard of wastes, and avoiding the overheating decomposition and the influence on crosslinking of organic raw materials such as starch by the methods of heating step by step and mixing step by step.)

1. a degradable film is characterized in that the degradable film comprises the following components in percentage by weight: PVA 50-60%, corn starch 20-30%, glycerin 20-30%, cross-linking agent PLA 2.5-3%, filling modifier sugarcane fiber 20-30% and purified water 870-1000%.

2. a method for preparing a degradable film based on the degradable film of claim 1, comprising the steps of:

A. Soaking: adding PVA 50-60% and purified water 500-600% into a steam heating stirring tank, stirring uniformly, standing and then reserving for later use; 20-30% of corn starch and 200-300% of purified water are added into a container 1 and soaked for standby after 4-6 h; adding 20-30% of glycerol, 2.5-3% of cross-linking agent PLA and 100-200% of purified water into a container 2, and uniformly stirring for later use;

B. Dissolving: preheating an electric heating stirring tank for 30min, setting the temperature to be 100-120 ℃, heating for more than 4h, stirring the mixture at the power of 100W and the rotating speed of 80r/min, and uniformly adding the material soaked in the container 1 for 4-6 h into the electric heating stirring tank when the electric heating stirring tank is heated for 3-4 h;

C. Mixing: adding the materials in the container 1, stirring for 30-60 min, then slowly dripping the mixed solution in the container 2 into a tank, stirring for more than 20min, finally adding 2.5-3% of the sugarcane fibers filled with the modifier into the tank, and stirring to complete copolymerization and mixing;

D. Standing: c, standing the mixed material obtained in the step C for more than 1h at the temperature of 100-120 ℃;

E. Film drawing: preheating a casting film machine in advance, transferring materials from an electric heating stirring tank to a material inlet of the casting film machine by using a pump, and performing casting film drawing and automatic winding;

F. Drying: the degradable film is dried in a drying chamber in a sectional temperature-divided manner;

G. And (3) storage: and collecting the degradable film from the casting film machine, and rolling and storing.

3. The method for preparing degradable film according to claim 2, wherein the time for steam heating the material in the stirring tank in step A to stand is not less than 12 h.

4. the method for preparing a degradable film according to claim 2, wherein the step A is further added with water, and the container 1 is refilled with 250-300% water.

Technical Field

The invention relates to the technical field of degradable films and preparation, in particular to a degradable film and a preparation method thereof.

Background

The situation characteristics of similar products in the current market are as follows: the PVA is used as a water-soluble material as a main component of a film, the product has the remarkable characteristics of water solubility, no toxicity, no odor, and capability of being degraded and utilized by microorganisms after being dissolved in water, the PVA has good antistatic effect after being formed into a film, can be directly printed without being subjected to corona treatment, but the manufacturing cost of the film is doubled compared with that of common plastics, the marketization process is slow, the strength of a food or non-food film made of the PVA is lower than that of the common plastics, but the degradation rate is very high, the environment protection effect is obvious, and the defects of similar products in the current market are as follows: the PVA film is very easy to dissolve in water, has insufficient water resistance, cannot be recycled for the second time, and is easy to dehydrate in a room temperature environment (the temperature is 25 ℃ and the humidity is 30%) after being prepared into the film, so that the film is dry, uneven, the service life is obviously shortened, the strength of the film is low, and all physical parameters of the film can not reach half of the strength of the common polyethylene film.

Disclosure of Invention

in order to solve the problems in the prior art, the invention provides a degradable film which can enhance the hydrophobicity and tensile strength and water retention capacity.

In order to achieve the purpose, the invention adopts the technical scheme that:

a degradable film comprises the following components in percentage by weight: PVA 50-60%, corn starch 20-30%, glycerin 20-30%, cross-linking agent PLA 2.5-3%, filling modifier sugarcane fiber 20-30% and purified water 870-1000%.

A preparation method of a degradable film comprises the following steps:

A. Soaking: adding PVA 50-60% and purified water 500-600% into a steam heating stirring tank, stirring uniformly, standing and then reserving for later use; 20-30% of corn starch and 200-300% of purified water are added into a container 1 and soaked for standby after 4-6 h; adding 20-30% of glycerol, 2.5-3% of cross-linking agent PLA and 100-200% of purified water into a container 2, and uniformly stirring for later use;

B. Dissolving: preheating an electric heating stirring tank for 30min, setting the temperature to be 100-120 ℃, heating for more than 4h, stirring the mixture at the power of 100W and the rotating speed of 80r/min, and uniformly adding the material soaked in the container 1 for 4-6 h into the electric heating stirring tank when the electric heating stirring tank is heated for 3-4 h;

C. Mixing: adding the materials in the container 1, stirring for 30-60 min, then slowly dripping the mixed solution in the container 2 into a tank, stirring for more than 20min, finally adding 2.5-3% of the sugarcane fibers filled with the modifier into the tank, and stirring to complete copolymerization and mixing;

D. Standing: c, standing the mixed material obtained in the step C for more than 1h at the temperature of 100-120 ℃;

E. film drawing: preheating a casting film machine in advance, transferring materials from an electric heating stirring tank to a material inlet of the casting film machine by using a pump, and performing casting film drawing and automatic winding;

F. drying: the degradable film is dried in a drying chamber in a sectional temperature-divided manner;

G. And (3) storage: and collecting the degradable film from the casting film machine, and rolling and storing.

Preferably, the time for the steam heating of the material in the stirring tank in the step A to stand is not less than 12 h.

Preferably, the step A is further added with water, and the container 1 is refilled with 250-300% of water.

the invention has the beneficial effects that:

(1) According to the invention, the sugarcane fibers filled with micromolecule filling modifiers are filled into macromolecular PVA and starch structures, and the PVA film with higher strength is obtained through the crosslinking action of the specific modifiers and the crosslinking agent PLA, so that the water resistance of the film is correspondingly enhanced, the film still keeps certain strength and elasticity after being soaked for a period of time, the film can be recycled for the second time, and is finally hydrolyzed and cracked after being soaked for a long time, the degradation process is very rapid, and the waste disposal is greatly reduced.

(2) the method of heating step by step and mixing step by step prevents organic raw materials such as starch and the like from being overheated and decomposed to influence crosslinking, and the sugarcane fibers filled with the modifier gradually can ensure that substances such as PVA, starch and the like are modified more completely and fully under the condition of uniform mixing, thereby avoiding various adverse factors caused by long-time heating.

(3) the mixture is more stable in structure and completely cured by standing for a long time.

(4) The film is prepared by adopting a tape casting method, so that the uniformity and the tensile strength of the film are effectively improved, the number of bubbles in the film is reduced by sectional cooling and drying, and the glossiness of the film is good.

Description of the drawings:

FIG. 1 is a schematic diagram of a production scheme of the present invention;

FIG. 2 is a schematic diagram of a production process of the present invention;

FIG. 3 is a schematic representation of the molecular structure of the mixture of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.