Compatibilized linear low‐density polyethylene/isotactic polypropylene blends studied by positron annihilation lifetime spectroscopy

Abstract

Positron annihilation lifetime spectroscopy (PALS), capable of probing free volume, is used to study the effect of compatibilizer concentration, compatibilizer type, and the effect of blend processing on the morphology and properties of an immiscible linear low‐density polyethylene/polypropylene system. It is proposed that improvement of fracture toughness due to compatibilization can be attributed to the packing (and bonding) at interfaces. Improved interfacial packing and bonding result in lower free volume concentration than expected from component additivity, with a concomitant increase in plastic deformation on impact.

Characterization of thermotropic liquid crystalline polyester/polycarbonate blends: Miscibility, rheology, and free volume behavior

“…Immiscible blends of LLDPE and isotactic PP were found to show I 3 decreasing with increasing compatibilizer concentration. 49 This was attributed to the better interfacial packing and bonding of the LLDPE/PP blends since the fracture toughness of the blends also showed an improvement. 49 Free volume fraction in polymers h f , can be estimated 50 from…”

The influence of metallocene-based LLDPE on polypropene compounds in the presence of SEBS and talcum

“…Previous studies have shown that compatibilization of PP/LLDPE blends with an ethylene-propene block copolymer (EP) and a triblock copolymer polystyrene-block-poly(ethylene-co-1-butene)-block-polystyrene (SEBS) significantly improves interfacial adhesion and dispersion of LLDPE. As a consequence, the mechanical properties, especially the impact resistance, are increasing [10][11][12] . Nevertheless, with respect to pure PP, most blends exhibit lower stiffness and toughness 11) .…”

Compatibilization of polyethylene/poly(propylene)/polystyrene blends

“…An addition of styrene-ethylene/butene-styrene (SEBS) copolymers enhanced the impact strength of LLDPE/PP blends [12][13][14][15] . Also a maleated SEBS copolymer enhanced the toughness of a LLDPE/PP blend 14) . An increase in impact strength was found for HDPE/PP blends compatibilized with styrene-butadiene-styrene copolymers 16) .…”