Influence of electron beam irradiation and polyfunctional monomer loading on the physico-chemical properties of polyethylene/polypropylene blends

Different polyethylene-polypropylene blends have been prepared in the presence of trimethylol propane trimethacrylate (TMPTMA) monomer. The prepared polymeric samples were cured using an electron beam accelerator at different irradiation doses ranging from 5 to 50 kGy. The influence of loaded TMPTMA wt% and irradiation doses on the physico-mechanical properties reveal that the gel content is higher for polyethylene-rich blend and reaches its maximum values at 30 kGy. Moreover, incorporation of TMPTMA monomer was found to positively influence the gel content of all samples under investigation. On the other hand, the mechanical strength increases on increasing the irradiation dose and attains its highest value at 20 kGy; a more pronounced effect was observed due to incorporation of TMPTMA into isotactic polypropylene (iPP) than LDPE samples at low irradiation doses. However, higher irradiation doses have a deleterious influence on iPP or iPP-rich blends. In addition to the physico-mechanical properties, the influence of TMPTMA loading as well as irradiation doses on heat shrinkage parameters of the neat polymers and their blends have also been studied. (c) 2006 Wiley Periodicals, Inc.