1 research outputs found
Phosphorus-Containing Poly(ethylene terephthalate): Solid-State Polymerization and Its Sequential Distribution
A series of phosphorus-containing
copolyester prepolymers were first sythesized from dimethyl terephthalate
(DMT), ethylene glycol (EG), and 2-carboxyethyl (phenyl)phosphinic
acid (CEPPA) by molten transesterification and polycondensation, and
then solid-state polymerization (SSP) was conducted for different
reaction times (<i>t</i><sub>SSP</sub>) so as to prepare
higher molecular weight copolymers. The intrinsic viscosity was increased
with the increase of <i>t</i><sub>ssp</sub>, but decreased
with the increase of CEPPA content. The sequence distribution of resultant
copolyesters was analyzed by <sup>1</sup>H NMR. It was found that
the randomness of copolyesters was decreased after SSP, and the transesterification
occurred mainly at the ester bonds formed by CEPPA and EG, resulting
in the chain growth. DSC results showed that SSP treatment was favorable
to enhance the crystallization ability of the obtained copolyesters