Morphology, phase structure, and properties of polyolefin/hydrogenated oligocyclopentadiene blends

The paper discusses the influence of an amorphous oligomer (namely hydrogenated oligocyclopentadiene - HOCP) on the morphology and the phase structure of its blends with several polyolefins as a function of composition and crystallization conditions. In particular the following polyolefins were studied: high-density polyethylene (HDPE), isotactic polypropylene (IPP), poly(1-butene) (PB-1), and poly(4-methyl pentene-1) (P4MP1). The blends under investigation are complex polymer systems. In fact, in dependence on temperature, blend composition, and cooling rate, they assume different morphologies and consequently show different thermal and mechanical behaviors. In the solid state the blends form a generally three-phase system: a crystalline phase of polyolefin and two amorphous phases, one rich in the amorphous polyolefin and the other in HOCP. The crystallization process and the properties are determined by the morphology and the phase structure, as well as by the physical state of the HOCP-rich phase.