Physical properties of CBDO based co-polyterephthalate nanocomposites

The co-polyterephthalate of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, 1,3-propanediol and dimethylterephthalate has been melt compounded with Cloisite 20A to form a composite that exhibits novel behavior. The composite yields a modest increase in stiffness but exhibits large increases in elongation at break and strong shape memory attributes. The physical data presented demonstrates that the composite is largely an intercalated tactoidal structure. The tactoids do however appear to be quite small. The composite also exhibits strain hardening that is not observed in the pure polymer. A mechanism involving the tactoids acting as temporary crosslinks is proposed as a mechanism to explain the unusual phenomena. Strong effects of tactoid orientation have also been identified as a significant source of variation in physical properties.