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Polyvinyl acetate (Polyvinyl Acetate, referred to as PVAc) is an important chemical raw material, with a wide range of applications, such as adhesives, coatings, emulsions and so on. This article will introduce the manufacturing method of polyvinyl acetate in detail.
1. raw material preparation
1. vinyl acetate monomer (Vinyl Acetate, referred to as VAc): vinyl acetate monomer is the main raw material for the production of polyvinyl acetate, generally by ethylene and acetic acid through vinyl acetate synthesis reaction.
2. Initiator: The initiator for initiating the polymerization of vinyl acetate monomer can be selected from persulfates, azo compounds and the like.
3. Dispersion medium: water or other organic solvent.
2. Polymerization
Polyvinyl acetate is mainly produced by solution polymerization. The specific steps are as follows:
1. add vinyl acetate monomer, initiator and dispersion medium into a polymerization reactor.
2. At an appropriate temperature and stirring speed, the initiator decomposes to generate free radicals, which initiate the polymerization of vinyl acetate monomer.
3. As the reaction proceeds, the polymer molecular chain grows to form polyvinyl acetate.
3. Post-Treatment
1. Termination of Reaction: When the molecular weight of the polymer reaches a predetermined value, a terminator is added to terminate the reaction.
2. Dewatering: Water remaining in the polymer is removed by vacuum dehydration or centrifugal dehydration.
3. Drying: The dehydrated polymer is dried to obtain the final polyvinyl acetate product.
Precautions for
4.
1. Strictly control the reaction temperature and stirring speed to ensure the smooth progress of the polymerization reaction.
2. The type and amount of the initiator are adjusted as required to control the molecular weight and molecular weight distribution of the polymer.
3. In the post-treatment process, ensure that the polymer is fully dehydrated and dried to avoid affecting its performance and use effect.
In short, the manufacturing method of polyvinyl acetate involves multiple links, and each process parameter needs to be strictly controlled to ensure the quality and performance of the final product. By mastering the manufacturing method of polyvinyl acetate, it can provide important raw material support for chemical production and promote the development of related industries.