Crystallization Kinetics of Homogeneous and Melt Segregated PE Containing Diblock Copolymers

Abstract

The crystallization behavior of four types of polyethylene (PE) containing diblock copolymers with an approximate 50/50 composition has been investigated and compared with their respective PE homopolymers. A glassy block of polystyrene (PS), a rubbery block of poly (D,L-lactide) (PDLA), a semicrystalline block of poly (L-lactide) (PLLA) and a miscible block of (poly(ethylene-alt-propylene) (PEP) were used to asses the influence of the degree of confinement and miscibility on the crystallization kinetics of PE. PEP had the largest effect on the crystallization kinetics of the PE block in view of its miscibility. For the strongly segregated systems larger restrictions were imposed by vitreous PS due to hard confinement as compared with the soft confinement of the rubbery PDLA block. A nucleation effect of previously crystallized PLLA on the PE block was detected which offset its depression of the crystallization kinetics of PE.