The influence of alkyl end-groups on the miscibility of hyperbranched polymers with polyolefins

Polyetherimide (PEI) hyperbranched polymers (HBPs) with alkyl terminated endgroups were blended with linear low density polyethylenes (LLDPEs) and extruded as thin films. The effects of length and concentration of the alkyl groups on the miscibility of the extruded films were examined using confocal and scanning electron microscopy (SEM). Surface properties of the blends were further characterized using contact angle measurements in de-ionized water. Results indicate that migration of PEI HBPs to the film surfaces is predominantly driven by the surface energy differences of HBPs and polyolefins. Moreover, the addition of PEI HBPs to LLDPEs has a negligible effect on the processing properties of LLDPEs.