Abstract
We study the degradation process and toughness of polymer composites by first-principles calculation and coarse-grained molecular dynamics simulation. To clarify the effect of water at the filler surface on the degradation of polymers, we calculate H abstraction of polyethylene by OH and H radicals. Activation barriers are 3.2 and 5.0 kcal/mol and these reactions easily occur at room temperature. Therefore, water molecules generate radical and cause degradation. Then, we study the toughness of melt and semicrystalline polymers with filler against the stretching by coarse-grained molecular dynamics simulation. In melt polymer, fillers increase the toughness but the toughness of degraded one decrease more than that without fillers. On the other hand, in semicrystalline polymer, fillers decrease the toughness but the toughness of degraded one decrease less than that without fillers.
