Graft polymerisation of acrylamide onto PCL film by electron beam pre-irradiation in air or argon. Morphology in the final grafted state

Poly(epsilon-caprolactone) has been graft polymerised to final graft yields with acrylamide (AAm) as monomer in an aqueous solution by the pre-irradia tion method. The synthesis of the samples obtained, pre-irradiated in air o r argon atmosphere, was controlled by dose and concentration of inhibitor, provided as Mohr's salt, in the ranges from 2.5 to 10 Mrad and from 0.005 t o 0.500 wt%, respectively. Final graft yields and lateral dimensions in swo llen condition ranged from 70 to 3400 wt%, and from 23 x 30 to 89 x 94 mm(2 ), respectively, as atmosphere during irradiation, dose and concentration o f inhibitor were altered. These properties gave values in crystallinity ext ending from 4 to 57 wt%. Samples pre-irradiated in air and subsequently gra ft polymerised yielded higher values of crystallinity in the entire range o f dose and concentration of inhibitor. At low concentration of inhibitor, f inal graft yield and lateral dimension for samples pre-irradiated in air ha d considerably larger values while the final graft yield and lateral dimens ion of samples pre-irradiated in argon had slightly larger values at high c oncentration of inhibitor. The initial biaxial morphology of the PCL film w as continuously transformed into a uniform morphology, which was reached at a final graft yield of approximately 800 wt%. (C) 2000 Elsevier Science Lt d. All rights reserved.