Method for hydrolyzing polyvinyl acetate to prepare polyvinyl alcohol in high-temperature liquid water under catalysis of organic acid

A technology of polyvinyl acetate and high-temperature liquid water, which is applied in the field of preparing polyvinyl alcohol by hydrolyzing polyvinyl acetate under the catalysis of organic acids in high-temperature liquid water, can solve the problems of long reaction time, weak catalytic effect, and product molecular weight drop, and achieve Effects of increasing reaction speed, reducing depolymerization, and improving quality
CN101712735BInactive Publication Date: 2011-05-18ZHEJIANG UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
ZHEJIANG UNIV
Publication Date
2011-05-18
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a method for hydrolyzing polyvinyl acetate to prepare polyvinyl alcohol in high-temperature liquid water under the catalysis of organic acid. The method comprises the following steps of: (1) adding an organic acid aqueous solution and polyvinyl acetate into a high-pressure reaction kettle, stirring, raising temperature to boiling under normal pressure and keeping a vent valve open for 2-4 minutes; (2) raising the temperature to 200-300 DEG C and hydrolyzing for 0.2-10 hours; and (3) cooling hydrolysis liquid and decompressing, steaming off water and organic acid under decompression, and then vacuum drying to obtain a solid polyvinyl alcohol product. The organic acid in the method is a green catalyst, and the addition of the organic acid can greatly improve the reaction velocity and reduce the polymer depolymerization so as to improve the quality of the product. Hydrolysis products can be used as fiber products such as civil clothing materials, industrial cord threads, filter screens, and the like, textile size, coatings, adhesive, paper making processing aids, packaging films, emulsifying agents, dispersing agents, oil drilling coagulant, soil improvement agents, medicine, cosmetics, and the like.
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Description

technical field

[0001] The invention relates to a method for preparing polyvinyl alcohol by hydrolysis of polyvinyl acetate under the catalysis of organic acid in high temperature liquid water. Background technique

[0002] Polyvinyl acetate (PVAC) is also known as polyvinyl acetate. The molecular structure is (CH 2 -CH(OOCCH 3 )) n , An amorphous polymer obtained by polymerization of vinyl acetate, which is a thermoplastic resin. Depending on the polymerization method, colorless latex or colorless transparent bead solid can be obtained. Soluble in aromatic hydrocarbons, ketones, alcohols, esters and chloroform. Initiated by free radical initiators from vinyl acetate, it can be produced by emulsion, suspension, bulk and solution polymerization. Mainly used as coating, adhesive, paper, chewing gum base and fabric finishing agent. It can also be used as a raw material for polyvinyl alcohol and polyvinyl acetal.

[0003] Polyvinyl alcohol (PVA) is a colorless and odorle...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
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