화학공학소재연구정보센터
Macromolecules, Vol.30, No.4, 959-965, 1997
Molecular-Structures in Poly(Vinyl Chloride) Thermoreversible Gels - Effect of Tacticity and of Solvent Type
Neutron scattering and neutron diffraction studies have been carried out as a function of the solvent type and of poly(vinyl chloride) (PVC) tacticity. In diesters, while the large scale structure of the gel does not depend significantly upon the nature of the alcohol group, the short-range structure differs markedly. In both cases a PVC-solvent complex is nevertheless formed. Neutron diffraction allows confirmation of the existence of such a complex in PVC/diethyl oxalate gels. By using bromobenzene, it has been observed that gels prepared from a PVC of higher syndiotacticity do not possess the same large scale structure as those produced from usual atactic PVC. Conversely, they are similar to those obtained in diethyl oxalate with the usual atactic PVC. These results highlight again the equivalence between tacticity and solvent type. This equivalence originates, however, in differing short-range molecular arrangements : complex formation in usual PVC/diethyl oxalate gels, "syndiotactic" crystals formation in highly syndiotactic/bromobenzene gels.