Shape memory effect of poly(ethylene terephthalate) and poly(ethylene glycol) copolymer cross-linked with glycerol and sulfoisophthalate group and its application to impact-absorbing composite material

Poly(ethylene terephthalate) (PET) and poly(ethylene glycol) (PEG) copolymers crosslinked with glycerol and sulfoisophthalate (SP) were prepared to investigate the feasibility of fabricating smart vibration-controlling composite laminate. The composition of glycerol and SP was varied to get a copolymer with the best mechanical and shape memory properties. The highest shape recovery was observed for the copolymer with 2.5 mol % of glycerol and 2.5 mol % of SP. With the high shape-recovery copolymer in hand, sandwich-type copolymer composites were made with epoxy beam laminate, and the copolymer composite, in the best case, showed improved impact strength (3.5 times) and damping effect (2.6 times) compared to epoxy laminate beam alone. The sandwich-type epoxy composite, together with the advantage of control of glass transition temperature by PET, PEG, or the additives, can be applied to structural composite material requiring vibration control. (C) 2004 Wiley Periodicals, Inc.