Characterization and quantification of the cross-linking of linear low density polyethylene with silane grafting by Fourier transform infrared (FTIR) spectroscopy

The way of making cross-linkable polyethylene through silane grafting has gained much attention in recent years because of its various advantages such as easy processing, low cost and capital investment and favorable properties in the processed materials. This work deals with silane grafting and moisture crosslinking of linear low density polyethylene (LLDPE). The grafting reaction was performed in an internal mixer using di-cumyl peroxide (DCP) as initiator and vinyl-trimethoxy silane (VTMOS) as grafting agent. Characterization and quantification of the grafting was performed by Fourier transform infrared (FTIR) spectroscopy. The cross-linking was done by subsequent immersion of grafted samples in hot water. The effect of silane and peroxide concentration was more considerable than time. The order of degradation temperature was: cross-linked LLDPE then grafted LLDPE and at last LLDPE.