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Synthesis and some properties of a series of polyterephthalates having side‐chain branching
Author(s) -
Fagerburg David R.
Publication year - 1985
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1985.070300301
Subject(s) - substituent , terephthalic acid , branching (polymer chemistry) , alkyl , side chain , ethylene , polyester , amorphous solid , polymer chemistry , ethylene glycol , materials science , poly ethylene , polymer , chain (unit) , chemistry , crystallography , organic chemistry , composite material , physics , astronomy , catalysis
Polyterephthalates made from terephthalic acid and a series of cyclic alkylene carbonates to give short side‐chain branching were amorphous. The T g increased from poly(ethylene terephthalate) to poly(1,2‐propylene terephthalate), and then an expected decrease in T g resulted from a further increase in side‐chain length. The initial increase in T g was attributed to increased chain rotational energy barriers. Further alkyl substituent length increases did not significantly raise these barriers but lowered chain packing densities. New group contribution factors for polyester T g calculations were derived from the data. Interpretations of the dynamic mechanical spectra showed an apparent decrease in trans ‐glycol unit fraction with increasing alkyl substituent length along with several interchain effects.