The source of the starch raw material of the corn starch degradable bag is extracted from various foods such as corn, rice, potatoes, etc., with an annual output of 400 million to 500 million tons, which is a rich and cheap raw material. There are two types of starch, direct starch synthesized by the combination of glucose through a-1,4 bond and amylopectin containing a-1,6 bond. Corn starch contains about 20% amylose, and the remaining about 80% is amylopectin. Because starch has many branches and lacks crystallinity, it has no characteristics of plastic when used alone. Therefore, the starch degradation bag we usually use is a bag made of degradable plastic film synthesized by mixing starch with other plastics.
The diameter of the starch particles in the degradable bag is 5~80um, which cannot be completely mixed with the plastic. In most cases, it will remain in the state of particles, resulting in a decrease in strength. Therefore, its use method is generally to crush starch and alkali together with hydrophilic acrylic resin to form a lipid bond, or graft the starch obtained after heating to plastic, and use it as a mixture of starch and plastic. However, no matter how the starch in the degraded bag is mixed with the plastic, attention should be paid to the decomposition of starch when the molding processing temperature rises.
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