Acetone-initiated photografting of methacrylic acid on low-density polyethylene film in water solvent

The effect of acetone on photografting of methacrylic acid (MAA) on low-den sity polyethylene (PE) film (thickness = 30 mu m) was investigated at 60 de grees C in water solvent. A maximum percentage of grafting was afforded at a certain concentration of acetone, while the percentage of homopolymer dec reased with increasing the acetone concentration (3-40 vol%). The total con version in the system also decreased with an increase in the acetone concen tration. The graft efficiency was less than 35%, showing an easier formatio n of homopolymer. These results suggest that acetone in the system acts as a photoinitiator as well as a screening agent. The resulting MAA-grafted PE film was characterized by a homogeneous distribution of the grafted chains , which was measured by an attenuated reflection infrared spectroscopy and an electron probe microanalysis, and higher pH-responsive character compare d to that prepared by photografting using xanthone photoinitiator, which ha d been coated on the film sample earlier. (C) 2000 Elsevier Science Ltd. Al l rights reserved.