| Summary: | 碩士 === 國立臺灣科技大學 === 高分子工程系 === 92 === In this work, we first investigated the degree of the polymer-solvent interaction by donor-acceptor principle, and then the properties of polyvinyl chloride solution and the solvent effects on the gelation behavior of PVC solution were discussed. The used solvents, MB (methyl benzoate), DMP (dimethyl phthalate), have same functional group but the number is different. The polymer-solvent interaction in PVC/MB solution is much higher than that in PVC/DMP solution, resulting that the properties of polyvinyl chloride solution and the gelation behaviors between these two solutions are quite different.
These results imply that the properties of polyvinyl chloride solution are related to the polymer-solvent interaction. The gelation ability and the polymer chain mobility in DMP solvent are higher than these in MB solvent.
Form the calculate resulted results based on thermal analysis, the structure of the junction point of PVC gels is irrespective of the species of solvent used. However, the rate and degree of the liquid-liquid phase separation, which mainly control the gelation behavior and the structure of the gel network, much depend on the solvent used. PVC/DMP solution exhibits a larger degree of the liquid-liquid phase separation, and the gelation occurs in the early stage of spinodal decomposition. The kinetic exponent that indicates the gelation mechanism is 0.45 for a three-dimensional percolation model. On the other hand, no the liquid-liquid phase separation or the spinodal decomposition occurs in PVC/MB solution, and the kinetic exponent that indicates the gelation mechanism is 2 for bimolecular association in the cross-link process.
|
|---|
