Study the effect of gamma irradiation on optical and morphological properties of grafted low density polyethylene

Radiation-induced graft polymerization of acrylamide (AAm) onto low density polyethylene (LDPE) samples has been investigated. The appropriate reactio n conditions at which the grafting process occurred were enhanced significa ntly by using dioxane as solvent. The optical absorption as a function of g rafted ratio from 1.4% to 24.2% and gamma irradiation dose for low-density polyethylene (LDPE) is presented. The optical absorption spectra were measu red in the wavelength range from 200 to 1100 nm at integrated gamma-doses f rom 1 to 20 Mrad. The calculated absorption coefficients and the determined values of energy gaps (E-0pt and Delta E) were found to be gamma-irradiati on dependent. The results indicated that, for LDPE, the validity of the Urb ach rule depends on the grafting and the irradiation dose. The morphologica l stability of grafted LDPE is investigated. Moreover, effect of gamma-radi ation on the stability of these morphologies, is examined. The results show that the morphology affect by low grafting is cracking, buckling and pock marking and for high grafting the contrast between faces was improved. Afte r radiation, the carbon black aggregates are smaller than before and the po ck marking and cracking more obvious. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.