In vinyl acetate emulsion polymerization, why should the monomer drop acceleration and polymerization temperature be strictly controlled?

In fact, the polymerization of VAC, like other liquid-liquid polymerization, has a certain drop acceleration and temperature allowable range. Here, regardless of their influence on the particle distribution of emulsion and the molecular weight of polymer, it is positive to reduce the gel alone!

The polymerization rate of VAC is low, and the reaction rate is about 1/4- 1/3 of that of styrene system. However, the polymerization heat is not low, and it is easy to be disturbed when it is added a little faster. The reflux of the cooler is too large, so the monomer can not enter the system to react normally to form gel, and the temperature increases! On the contrary, in short, there is a corresponding relationship among dropping speed, temperature and cooling, and mastering control skills is the basic requirement of emulsion polymerization operators!

Vinyl acrylate latex paint can make the coating film have suitable hardness, flexibility, solubility and adhesion. Vinyl phenylacetate-acrylate latex paint belongs to low-cost matte latex paint for ethylene-propylene interior walls, which is used for interior decoration and general engineering coatings.

Extended data:

Vinyl acetate is a monomer, which can be polymerized into polyvinyl acetate alone or with other monomers to form a polymer, such as ethylene-vinyl acetate polymer. Because of the instability of free radicals, there are some problems in trying to control the polymerization process.

RAFT (or more precisely MADIX) polymerization provides a simpler method to synthesize polyvinyl acetate, in which sulfonate is added as a chain transfer agent.

Vinyl acetate can react with most olefins or esters. For example, bromine is added to produce dibromide, and hydrogen halide is added to produce 1- vinyl haloacetate, which is also the only way to prepare this substance, because there is no corresponding halogenated alcohol.

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