Morphology, fractionation and differential scanning calorimetry (d.s.c.) studies point to very-low-density polyethylene (VLDPE) being a heterogeneous blend of molecules with widely different comonomer contents. The morphology of VLDPE shows distinct regions of highly different crystallinity. This highly crystalline dispersed phase occurs in smooth, spherical compact semicrystalline domains, which are believed to be due to demixing in the melt. The mixing and demixing of a heterogeneous ethylene-octene copolymer as a function of time and temperature and the influence of crystallization on this behaviour is studied with d.s.c, and transmission electron microscopy. The results show clearly that mixing occurs at higher temperatures, that demixing occurs in the melt and that under certain conditions this demixing is binodal in character
Посилання на статтю:
Mixing and demixing of heterogeneous ethylene-octene copolymers: evidence for binodal melt demixing* / Jippe van Ruitent and Jan Willem Boode // Polymer. – 1992. – Vol 33. – P. 2548-2552.