A Study on the Antiplasticization of Polyvinylchloride

PVC의 역가소화 기구에 관한 연구

Influence of dioctyl phthalate (DOP) on the physical properties of polyvinylchloride (PVC) were examined, and the antiplasicization mechanism was inv estigated by measuring dynamic mechanical properties and specific volume. Above the glass transition temprature (Tg), small amount of DOP plasticized PVC but an antiplasticizing was observed below Tg. The antiplasticization effect was more pronounced at lower temperatures. DOP seemed to suppress the mobility of PVC chains in the glassy state. Annealing appeared to suppress the relaxation of PVC chains further. Both antiplasticization and annealing widened the spread of $\alpha$-dispersion peak but reduced the height of the peak. Annealing shifted the maximum values of $\alpha$-dispersion peak(Tg) to higher temperatures. The dynamic mechanical properties and specific volume suggest that the antiplasticization is caused by a reduction of free volume due probably to polar-polar interactions between PVC chains and DOP molecules.