Photografting of Maleic Anhydride on Low Density Polyethylene Powder in the Vapor Phase

Graft copolymerization reaction of maleic anhydride (MAH) on low density polyethylene (LDPE) powder, the surface structure and adhesive properties of grafted LDPE powder were studied by grafting measurement, Fourier transform infrared (FT-IR), electron spectroscopy for chemical analysis (ESCA) and peel strength test. The surface of chemical inert LDPE powder can be graft-copolymerized with MAH by photografting in the vapor phase. In this way, grafting is increased with reaction time and temperature. Suitable reaction temperature should be over the melting point of MAH (52.8°C). The peel strength of LDPE and steel adhered by the grafted LDPE powder is much enhanced compared with that by ungrafted LDPE powder. At 80°C graft copolymerization temperature and 2.5 h copolymerization reaction time, grafted powder has a very good adhesive property to LDPE and steel, and the sample breaks in the peel strength test. In this case, LDPE bulk strength is lower than adhesion strength.