Synthesis of styrene–maleic anhydride copolymer esters and their surface enriched properties when blending with polyethylene

Three kinds of comb-like amphiphilic copolymers based on styrene–maleic anhydride copolymer (SMA) backbone and long fatty alcohol grafts were synthesized by esterification of SMA with octanol, tetradecanol and octadecanol, respectively. SMA and the esters were used as surface modifiers to blend with high density polyethylene (HDPE). The surface composition of the binary blends has been determined by Attenuated Total Reflection Fourier Transform infra-red (ATR-FT-IR) spectroscopy. It was found that grafting of alcohols onto SMA can promote the enrichment of the modifiers on the surface of the blending film, and that the enrichment effect enhances when using shorter fatty alcohols. The data of contact angle measurements and surface tension of the blend film show that the addition of SMA esters to HDPE can improve the hydrophilicity of the HDPE surface.