Studies on two series of segmented polyester polyurethaneurea (PUU) elastomers based on 4

4-diphenylmethane diisocyanate(MDI)

ethylene diamine(ED) and polybutylene adipate (PBA)(M. W. 1975 and M. W. 1228) were made by DSC. Further

thermal changes of soft segment crystalline of these materials at different annealing conditions were also investigated. The results showed that in both series

PBA 1975 series had a lower T

of soft segment phase than PBA 1228 series

indicating that the phase segregation of the former was better

Both the soft segment Tgs and the hard segment Tgh were not sensitive to the changes of the hard segment contents in the samples. The results on the annealed samples showed that soft segment crystal-line melting existed in two peaks. The hypothesis of the existence of two types of crystallines (P2 and Ph) in the soft segment phase was proposed

and the reason that these two types of crystallines formed was analyzed theoretically.