Effects of fusion temperature and metal ion variation on crystallization of lightly ionized poly(butylene succinate)

摘要

Crystallization behavior was investigated for poly(butylene succinate) -based ionomers (PBSIs) with very small amounts of metal sulfosuccinate units. The PBSI samples, precipitated by adding their chloroform solutions into an excess volume of hexane, showed not only higher overall crystallization rates than the parent PBS but also strong fusion temperature dependences of the crystallization kinetics. In the early stage of film-hydrolysis experiments, the center region of PBSI spherulites was found to be easily eroded. A putative internal structure of PBSI spherulites, that is, relatively ion-rich centers and ion-poor outskirts, was proposed. PBSIs with K ions were found to show higher crystallization temperatures than those with Na ions in the non-isothermal crystallization from the melts. These results indicate that the crystallization behavior of PBSIs is dominated by the ionic aggregates which induce the crystal nucleation around themselves.