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A solid‐state NMR study of aromatic polyimides based on 4,4′‐diaminotriphenylmethane
Author(s) -
MartínezRicha Antonio,
VeraGraziano R.
Publication year - 1998
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/(sici)1097-4628(19981109)70:6<1053::aid-app2>3.0.co;2-n
Subject(s) - polyimide , condensation polymer , polymer , polymer chemistry , materials science , chemical shift , chemical structure , carbon 13 nmr , thermal stability , solid state nuclear magnetic resonance , solid state , nmr spectra database , chemical engineering , spectral line , organic chemistry , chemistry , composite material , nuclear magnetic resonance , layer (electronics) , physics , engineering , astronomy
The effect of different synthesis routes on the chemical and molecular order of polyimides based on 4,4′‐diaminotripenylmethane (DA‐TPM) and various aromatic dianhydrides (PI‐TPM) was studied by solid‐state carbon‐13 nuclear magnetic resonance ( 13 C‐NMR). Polyimides were prepared by three different methods including a two‐step procedure with either thermal or chemical imidization of precursor poly(amic acid)s (PAA) and one‐step high‐temperature polycondensation in phenolic solvents. Model compounds were also obtained and used in the assignment of the NMR signals. The NMR spectra for PI‐TPMs obtained by one‐step high‐temperature polycondensation and—to a lesser extent—by thermal imidization of PAA, show sharper lines than those observed in the spectra of polymers prepared from PAA via chemical imidization. These differences are due mainly to the lower degree of ordering of the latter polyimides. WAXD patterns of polyimide films also indicated a less‐ordered structure of the polymers resulting from the chemical imidization of PAA. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1053–1064, 1998