No abstract

The effect of graft ratio on the dynamic moduli of ABS (Acrylonitrile‐Butadiene‐Styrene Copolymer) has been investigated. Unlike previous papers, the storage modulus at low frequency shows both minimum and maximum as graft ratio increases, and the rubber particles do not agglomerate significantly at high graft ratios. The dependence of the rheological properties on the graft ratio is quite complicated. This arises from its morphological change that leads to different interactions between the rubbery phase and the matrix phase. The minimum has been reported previously, and is explained in terms of rubber dispersion. However, the maximum at high graft ratio has never been reported. The origin of maximum seems to come from the repulsive forces between the long graft chains of neighboring rubber particles. Analogy between our experimental results and simulation results has been discussed to deduce the mechanism of maximum storage modulus at high graft ratio.