Polyvinyl alcohol water-soluble foamed plastic as well as preparation method and application thereof

Abstract

The invention discloses a polyvinyl alcohol water-soluble foamed plastic and a preparation method thereof. The method comprises the following steps: polyvinyl alcohol powder with a polymerization degree of 500-2400 and an alcoholysis degree of 85-99% and water are used as main raw materials, under the condition of avoiding to use an acetalating agent or a crosslinking agent, a production process is improved, firstly, swelling is performed by using hot water of specific temperature, then extrusion processing is performed to form a foamable particle material, and finally the polyvinyl alcohol foamed material is prepared by a rapid heating method or an instantaneous decompression method. The method disclosed by the invention makes the product kept very good water solubility, and has a relatively simple process and low costs; and the prepared polyvinyl alcohol water-soluble foamed plastic has very good water solubility, can be widely used in the fields such as disposable medicines, packaging and pharmacy, and has the characteristics of easy degradation.

Description

technical field [0001] The invention belongs to the field of foamed plastics or polymer foamed materials, and in particular relates to a polyvinyl alcohol water-soluble foamed plastic and its preparation method and application. Background technique [0002] Polymer foaming materials have been widely used in many fields such as packaging, medicine, electronics, automobiles, aerospace, building energy conservation, etc., but the foaming materials currently used are difficult to degrade and have a great impact on the environment when discarded. Therefore, manufacturing a It is very necessary to have a water-soluble, biodegradable foaming material to replace the traditional polyolefin foaming material. [0003] As a water-soluble polymer, polyvinyl alcohol (PVA) is a biodegradable polyolefin, which can be decomposed into carbon dioxide and water by microorganisms in the environment, and is an environmentally friendly material. If polyvinyl alcohol is used instead of common poly...

AI Technical Summary

Problems solved by technology

[0005] At present, the molded foaming method and solution casting method are commonly used in China to prepare polyvinyl alcohol foam materials. The production cycle is long, the process is complicated, the operation is complicated, and there are residues of chemical foaming agents or acetals.

Although the process of preparing polyvinyl alcohol foam by thermoplastic extrusion foaming is simple, its disadvantage is that the nucleation and growth of bubbles are carried out in one step, which is not easy to control

In the above-mentioned foaming materials for the preparation of polyvinyl alcohol, acetal agents or crosslinking agents are generally added to make the products in use water-insoluble, which affects their degradation in the environment to a certain extent, on the other hand It also loses the feature of polyvinyl alcohol as a water-soluble polymer

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