ELECTRON-BEAM-INITIATED GRAFTING OF TRIALLYL CYANURATE ONTO POLYETHYLENE - STRUCTURE AND PROPERTIES

Electron-beam (EB)-initiated grafting of triallyl cyanurate (TAC) onto polyethylene (PE) has been carried out over a range of radiation dose s (2-20 Mrad) and concentrations of TAC (0.5-3 parts by weight). The g rafting level, as determined from IR spectroscopy, is maximum at a 10 Mrad radiation dose using 1 part TAC. With increasing TAC level at a 1 5 Mrad dose, the grafting level is higher only after 1.5 parts TAC. Th e gel content increases with radiation dose in the initial stages. X-r ay studies indicate two peaks at 10.6-10.8-degrees and 11.7-11.9-degre es and the corresponding interplaner distances of 4.15 and 3.80 angstr om. With increase in radiation dose or TAC level, the crystallinity de creases in the initial stage and then increases. It shows a decreasing trend again at higher radiation dose. The interplanar distance or the interchain distance of the modified polymer does not change. However, the crystallite size increases initially and then decreases. The tens ile properties are relatively insensitive to the variation of radiatio n dose because of the interplay of various factors. The dielectric los s, tan delta, shows a maximum at a 10 Mrad dose and minimum at 5 and 1 5 Mrad due to changes of polarity and the carrier mobility. (C) 1994 J ohn Wiley & Sons, Inc.