Abstract
To prepare linear high molecular weight polyvinylalcohol(PVA) suitable for dry jetwet spinning, a low temperature initiator, 2,2'-azobis(2,4-dimethylvaleronitrile) (ADMVN), was utilized in bulk-polymerization of vinyl acetate(VAc). ADMVN showed equilibrium in polymerization at conversion 13% and 2,2'-azobisisobutyronitrile (AIBN), at 23%. Polyvinyl acetate(PVAc) obtained at 30℃ by ADMVN gave low degree of branch 0.6, value of which may be compared with 1.1 for PVA prepared by AIBN at 50℃. PVA saponified from PVAc obtained by ADMVN at 30℃ gave number-average degree of polymerization ($P_{n}$) 6000 while PVA saponified from PVAc prepared by AIBN at 50℃ gave $P_{n}$ 2800. However, the type of initiator did not have a notable effects on the tacticity of resultant PVA.