Studies On The Preparation Of Polyvinyl Alcohol With Low Degree Of Polymerization And Low Degree Of Alcoholysis

In this paper, the preparation and alcoholysis of polyvinyl acetate of low degree polymerization were studied, and the structures and properties of the resulting polymers were studied.First, the preparation of polyvinyl acetate of low polymerization through the solution polymerization method was studied. It was found that the temperature, the concentration of initiator and the ratio of vinyl acetate/solvent affect the polymerization seriously.Next, the solution alcoholysis and suspension alcoholysis process were discussed. The effect of the reaction time, temperature, the concentration of reactant and catalyst on the alcoholysis process were investigated. In the suspension alcoholysis process, the degree of alcoholysis could be efficiently controlled by changing the concentration of catalyst and suspension agent.Then, the structures of low degree of polymerization polyvinyl acetate and polyvinyl alcohol with FTIR, 1H NMR , 13C NMR and GPC were characterized. The results showed that head-head and head-tail connection coexist in either polyvinyl acetate or polyvinyl alcohol. In view of the results, we investigated the polymerization mechanism of vinyl acetate.Finally, the properties of the resulting polymers, such as solubility, tensile strength, temperature of transformation, surface tension were investigated.