Photografting of acrylic acid on high density polyethylene powder in vapour phase

A photografting technique was explored as a means of functionalizing high d ensity polyethylene (HDPE) powder. The graft copolymerization reaction of a crylic acid on HDPE powder and the surface structure of grafted HDPE powder were studied in terms of grafting degree and grafting efficiency, and by F TIR and ESCA. The results show that the surface of chemically inert HDPE po wder pretreated by an acetone solution of benzophenone (BP) can be graft-co polymerized with acrylic acid by photografting in the vapour phase. Thereby , the grafting degree is increased but the grafting efficiency is decreased with increasing reaction time. When the BP concentration in pretreatment s olution is increased, the grafting degree is increased to a maximum, and is then reduced. The most suitable reaction temperature is 90 degreesC. Graft ing degree can reach the quite high value of 10.6wt% under the conditions o f BP concentration 1.0wt%, reaction time 1 h and temperature 90 degreesC. ( C) 2000 Society of Chemical Industry.