Free radical modification of LDPE with vinyltriethoxysilane

Chemical modification of low density polyethylene (LDPE) with vinyltriethoxysilane (VTES) was studied. The melt reactions were performed in a mixer and were initiated by thermal decomposition of a peroxide. The degree of functionalization was determined by Fourier transform infrared spectroscopy and Rutherford backscattering spectrometry. It was verified that the degree of functionalization increased with VTES and peroxide concentrations showing high conversion, up to 86 wt.%. No functionalization was observed in the absence of peroxide. Functionalized products showed some gel content and lower crystallinity than the parent homopolymer, affecting the stress/strain behavior. Yielding stress, elongation at break and elastic modulus decreased for the modified PE.