Structure and property relationship in long-term ageing maleic anhydride grafted styrene-b-(ethylene-co-butylene)-b-styrene triblock copolymer

Abstract

In this study, the relationship between the structure and property in a long-term ageing thermoplastic elastomer, maleic anhydride grafted styrene-b-(ethylene-co-butylene)-b-styrene triblock copolymer (termed as mSEBSa) was thoroughly studied. This mSEBSa sample had been stored in the laboratory for over nine years, which was considered as a polymer elastomer waste. A fresh normal mSEBS sample was also examined in the meantime for comparison. The mechanical tensile strength, rheological storage and loss moduli of mSEBSa were much high as compared to that of the fresh normal mSEBS, which was contrary to the general viewpoint about the ageing, which led to polymer degradation. The microphase morphological observation and molecular structure analysis revealed that the long-term ageing of mSEBS at ambient could result in some chain scissions, leading to production of chemical groups at the chain endings, therefore, the physical/chemical interactions in the ageing thermoplastic elastomer could occur, which eventually affected significantly the various physical properties of this typical elastomer.