The random and block copolyesters of poly(ethylene 2,6 naphthalate) (PEN) and poly(ethylene terephthalate) (PET) are synthesized and studied by 1 H-n.m.r., DSC, X-ray. The block length decreases and the degree of transesterification increases at a similar composition ratio. The melting point depressions occur with increasing the content of the other component, and melting peaks disappear at a similar composition ratio. The results of X-ray diffractograms match well with those of dyads fraction, block length, and DSC. It can be seen that a critical block length is needed for components in order to crystallize.
Посилання на статтю:
Relationship between sequence distribution and transesterification of PEN/PET random/block copolyesters / Ho Wook Jun, Seung Hun Chae, Sang Soon Park, Hee Soo Myung, Seung Soon Im // Polymer. – 1999. – N 40. – P. 1473–1480.