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Synthesis and properties of polydiacetylene‐containing polyesters
Author(s) -
Lovell P. A.,
Stanford J. L.,
Wang YF.,
Young R. J.
Publication year - 1994
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1994.210340105
Subject(s) - diacetylene , crystallinity , polyester , materials science , molar mass , raman spectroscopy , terephthaloyl chloride , polymer chemistry , polymerization , composite material , polymer , condensation polymer , physics , optics
A series of diacetylene‐containing polyesters with number‐average molar masses (GPC) in the range 900–4200 g mol −1 were prepared from terephthaloyl chloride and hexa‐2,4‐diyne‐1,6‐diol using benzoyl chloride as a monofunctional reactant for control of molar mass. Degrees of crystallinity were estimated from WAXD to be up to 29%. Correlations between molar mass, melting behaviour, degree of crystallinity and thermal cross‐polymerisation of diacetylene‐containing polyesters have been established using hot‐stage microscopy, DSC and resonance Raman spectroscopy. The polyester with M̄ n of 1264 g mol −1 gave the best balance between processability and the ability to cross‐polymerise efficiently. Its degree of crystallinity before cross‐polymerisation was estimated from WAXD measurments to be 24%, a value coincident with the percentage conversion of diacetylene units to polydiacetylene chains measured by 13 C solid‐state NMR. The optimum conditions for compression moulding the polyester to produce a material with a strong Raman spectrum involved heating under vacuum at 120°C for 6h after an initial 3 h heat‐up period. The material thus produced gave an intense Raman CC stretching band, which upon tensile deformation shifted linearly with strain to lower wavenumber by 12.0 cm −1 % −1 . The potential use of the diacetylene‐containing polyesters in the preparation of model blends for use in quantitative micromechanics studies of stress transfer between phases is briefly discussed.