Thermoplastic starch with ultrahigh starch content as well as preparation method and application thereof

Abstract

The invention discloses thermoplastic starch with an ultrahigh starch content as well as a preparation method and application thereof. The thermoplastic starch with the ultrahigh starch content comprises the following raw materials in parts by weight: 60-85 parts of edible starch, 10-40 parts of a composite plasticizer, and 0-5 parts of a processing aid, wherein the composite plasticizer comprises water, maleic anhydride and a hyperbranched polymer. The composite plasticizer disclosed by the invention has an excellent plasticizing effect on starch, and more importantly, water serving as a main plasticizer is extracted and removed when passing through a vacuum port, so the prepared thermoplastic starch only contains extremely few micromolecular plasticizers, a starch content is up to 90% or above, almost no smoke is generated in the processing process, and meanwhile, the general requirements of potassium permanganate consumption tests for food contact materials and products thereof are met; and a degradable food packaging material and tableware which are subsequently processed have excellent mechanical properties, and production cost is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of biodegradable materials, in particular to a thermoplastic starch with ultra-high starch content, a preparation method and its application in the preparation of degradable food packaging materials and tableware. Background technique [0002] With the acceleration of the industrial process and the improvement of living standards, a large amount of plastic products are produced and consumed every day in daily life. However, these ordinary plastic products are quite troublesome to deal with after they are discarded. Burning will produce toxic gases, pollute the atmosphere, and fill the air. It takes one or two hundred years to completely degrade after being buried, and it causes serious waste of land resources. [0003] Biodegradable materials refer to materials that can be completely decomposed into low-molecular compounds by microorganisms (such as bacteria, fungi, and algae, etc.) under appropriate and def...

AI Technical Summary

Problems solved by technology

But on the one hand, compared with starch, the cost of this type of small molecule plasticizer is higher, and the production cost will be significantly increased at a higher dosage; on the other hand, in the process of processing (injection molding, extrusion, blow molding, etc.) Under the high temperature conditions, the small molecule plasticizer will volatilize and produce a lot of smoke when the amount of addition is high, which seriously affects the factory environment. More importantly, the produced disposable catering products will have some small molecule plasticizers. Migration of the agent into food may have adverse effects on human health

Compared with small-molecule plasticizers, some low-molecular-weight polymer plasticizers, such as polyethylene glycol, have a high flash point and are not easy to volatilize and produce smoke, but the plasticizing effect is poor. Plasticization, resulting in a decrease in the mechanical properties and strength of the material

If the amount of plasticizer used is increased in order to enhance the plasticizing effect, the addition of a large amount of low-molecular materials will weaken the mechanical strength of starch

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