Synthesis and characterization of poly(ethylene terephthalate - co - 1,4 cyclohexylenedimethylene terephthalate)

Although Poly(ethylene terephthalate) has many positive properties which make it a widely appreciated industrial thermoplastic, some of this polymer's properties such as high crystallization degree, low Tg and low impact strength limited its applications. Copolymerization of this thermoplastic is one of the solutions to improve its applications. Poly(ethylene terephthalate -co- 1,4-cyclohexanedimethanol) copolymers, containing from 5 up to 30 mole% cycloaliphathic diol, CHDM, as well as the parent homopolymer, PET, were prepared from comonomers mixtures by a two step melt polycondensation procedure in one homemade reactor. Copolymer intrinsic viscosities varied from 0.24 to 0.4 dLg-1.The composition of copolymers were preceisely determined by NMR spectroscopy. It is observed that CHDM composition in the copolyester's chain is more than its composition in the feed. Based on the NMR spectra, the copolymers were found to have a random microstructure.

Keywords:

PET , 1 , 4-cyclohexanedimethanol , copolymer , synthesis