Polyvinyl Alcohol - China

Brief Overview

Polyvinyl alcohols, also known as Polyethanol or PVA, are polymers from its monomer vinyl alcohol. Polyvinyl alcohol is physically odorless and tasteless, translucent, non- toxic, white or cream colored granular powder. The specific functional and physical characteristics of polyvinyl alcohol will depend on the degree of hydrolysis and the degree of polymerization. Because of that, polyvinyl alcohol is classified into two classes namely: partially hydrolyzed and fully hydrolyzed. Partially hydrolyzed PVA is usually applied in the food industry.

Manufacturing Process

The primary raw material used in the manufacture of polyvinyl alcohol is a vinyl acetate monomer. It is manufactured by the polymerization of vinyl acetate followed by partial hydrolysis. The process of hydrolysis is based on the partial replacement of the ester group in vinyl acetate with the hydroxyl group and is completed in the presence of aqueous sodium hydroxide. Following gradual addition of the aqueous saponification agent. Polyvinyl alcohol is precipitated, washed, and dried. The degree of hydrolysis is determined by the time point at which the saponification reaction is stopped.

Agriculture Industry

Polyvinyl alcohol (PVA) is used as a soil improving agent and pesticide reinforcing agent.

Chemicals Industry

Polyvinyl alcohol is used as a polymer emulsifying agent, dispersing agent, and used to produce PVA formal, PVA acetal, PVA butyral.

Construction

PVA is used as an additive to cement and mortar for an efficient increase of their cohesion and fluidity, and reduce the drying time for the concrete surface, thus increasing coating adaptability and preventing the concrete cloth from chapping.

Food Industry

In food manufacturing, polyvinyl alcohol (PVA) is used as a food additive used as a film coating agent for food supplements.

Paper Industry

PVA is used as a binding agent for paper, re-moistening agent, paper surface sizing. It is also used for paper pigment coating and papermaking.

Textile Industry

Polyvinyl alcohol is used as a warp dressing agent, textile finishing agent, and the raw material of vinylon.