Influences of Grafted Side Chains on the Viscoelastic Behavior of Ternary Graft Copolymers

Abstract

The novel ternary graft copolymers with long grafted side chains were prepared by solid phase grafting maleic anhydride (MAH), methyl methacrylate (MMA), and butyl acrylate (BA) onto polypropylene (PP). GPC was employed to show the length of the grafted side chains. The viscoelastic behavior was investigated by DMA. The results showed that the storage modulus and the loss modulus decreased with increase of the length of the grafted side chains but the α relaxation characterized by tanδ has no distinct change after various grafting. The distinct change of the internal damping of the graft copolymers was characterized by Cole-Cole curves. The storage modulus was successfully superposed according to the WLF and VFTH equations, which are suitable to describe the TTS principle for these ternary graft copolymers. When the weight percentage of MAH/MMA/BA was 6/6/2, the PP matrix had been overwhelmed by the grafted side chains, resulting in the change of the matrix properties and the dramatic increase of activation energy which was calculated by the Arrhenius equation. Meanwhile, the length of the grafted side chains was long enough to be discovered by TGA and DTG.