Preparation and properties of polyether pentaerythritol mono-maleate grafted linear low density polyethylene by reactive extrusion

摘要

A reactive type nonionic surfactant, polyether pentaerythritol mono-maleate (PPMM) was synthesized in our laboratory. PPMM was adopted as functionalizing monomer and grafted onto linear low density polyethylene (LLDPE) with a melt reactive extrusion procedure. FT-IR was used to characterize the formation of grafting copolymer and evaluate their degree of grafting. The effects of monomer concentration, reaction temperature and screw run speed on the degree of grafting were studied systematically. Isothermal crystallization kinetics of LLDPE and LLDPE-g-PPMM samples was carried out using DSC. Crystallization rates of grafted LLDPE were faster than that of plain LLDPE at the same crystallization temperature. The tensile properties and light transmission of blown films were determined. Comparing with neat LLDPE film, no obvious changes could be found for the tensile strength, elongation at break and right angle tearing strength of LLDPE-g-PPMM film. The wettability is expressed by the water contact angle. With an increasing percentage of PPMM, the contact angles of water on film surface of LLDPE-g-PPMM decrease monotonically. The acceleration dripping property of film samples was investigated. The dripping duration of LLDPE-g-PPMM film and commercial anti-fog dripping film at 60 degrees C were 76 days and 17 days, respectively.