| Abstract: | Functionalization of poly(ethylene‐co‐vinyl acetate) (EVA) with vinyltriethoxysilane (VTEOS) has been carried out by a free‐radical melt‐grafting procedure in the presence of added comonomers. The influence of comonomers on silane graft yield and crosslink density has been assessed. Experiments were performed on masterbatches of EVA, VTEOS (5 wt %), peroxide initiator (L‐231, 0.05 wt %), and comonomer (0–1 comonomer : VTEOS mole ratio) prepared at 90°C. Melt‐grafting experiments were carried out at 145°C in an oscillating disk rheometer (ODR), which measured crosslink density during the grafting process. Silane graft yields were determined by proton NMR spectroscopy. Comonomers evaluated were maleic anhydride (MAn), 1‐vinyl‐2‐pyrrolidone (VP), and 1‐dodecene (DD). At the comonomer ratios examined, MAn suppressed both silane grafting and peroxide‐initiated crosslinking. Both VP and DD, however, exhibited greater selectivity in suppressing crosslinking than silane grafting; optimum performance was found at a comonomer : vinylsilane mole ratio of 0.2. None of the comonomers studied enhanced the level of silane grafting. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1308–1314, 2000 |
