%0 Journal Article
%A Sono, Masayo
%A Kinashi, Kenji
%A Sakai, Wataru
%A Tsutsumi, Naoto
%D 2018
%T Spin-Trapping Analysis and Characterization of Thermal
Degradation of Thermoplastic Poly(ether–ester) Elastomer
%U https://acs.figshare.com/articles/journal_contribution/Spin-Trapping_Analysis_and_Characterization_of_Thermal_Degradation_of_Thermoplastic_Poly_ether_ester_Elastomer/5838270
%R 10.1021/acs.macromol.7b02654.s001
%2 https://acs.figshare.com/ndownloader/files/10337160
%K PBT
%K DSC
%K OCH
%K co
%K DMA
%K PEO
%K TPEE
%K CH
%K NMR
%K TGA
%K ESR
%K GPC
%K thermo-oxidative degradation
%X We investigated the
thermal degradation of poly(butylene terephthalate)-co-poly(ethylene oxide) (PBT-co-PEO), a
thermoplastic poly(ether–ester) elastomer (TPEE), through proton
nuclear magnetic resonance (NMR) spectroscopy, differential scanning
calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical
analysis (DMA), gel permeation chromatography (GPC), and spin-trapping
electron spin resonance (ESR) analysis to detect radical intermediates
present during degradation. Three kinds of PBT-co-PEO with different component ratios of PBT/PEO were synthesized.
The thermal degradation process of PBT-co-PEO was
divided into four weight-loss stages. In the first stage from room
temperature to 120 °C, we confirmed the production of two radical
intermediates, O–•CH–CH2 and •CH2–, by the spin-trapping
method. This suggested that the initial decomposition occurred at
the OCH2–CH2O bond in the PEO units.
Upon annealing at 120 °C, PBT-co-PEO showed
a small degree of random degradation, while higher PBT contents induced
gelation and the production of the characteristic oligomer PBT–PEO–PBT.
The gelation was attributed to cross-linking between two O–•CH–CH2 moieties of PBT. In the second
stage from 120 to 340 °C, a large thermo-oxidative degradation
of the PEO segment occurred, accompanied by an increase in the radical
amount of spin adducts. In the third stage, the thermo-oxidative degradation
of PBT units was observed. The radical intermediates were thus shown
to be a primary factor of the thermal degradation characteristics
of TPEE.
%I ACS Publications