New trends to synthesis and application of polyvinyl alcohol

Poly(vinyl alcohol) (PVA), obtained by the hydrolysis of poly(vinyl ester)s such as poly(vinyl acetate) (PVAc) and, is a linear and crystalline polymer that has been widely used as fibers for clothing and industrial uses, films, membranes, medicines for drug delivery systems, and cancer- cell-killing embolic materials. One of the most important challenges in producing polyvinyl alcohol is obtaining linear high molecular weight (HMW) PVAc by free radical polymerization, which is a representative precursor for HMW PVA, because the polymerization involves chain transfer reactions, leads to branching. Therefore, linear HMW PVA has been prepared only by special polymerization methods. Vinyl acetate monomer can be polymerized via bulk, solution, emulsion, and suspension polymerization processes.