ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The viscoelastic properties of cured acrylate-terminated copolyesters were studied by means of dynamic mechanical analysis. The influence of terminal double bonds, as well as of the cis-trans configuration and distribution along the main chain, on the transition temperatures and rheological properties of the cured polyesters are presented. The presence of double bonds at both chain ends allows the formation of a regular network by crosslinking copolymerization with styrene. The present investigation was carried out on three series of acrylate-terminated copolyesters: poly[(tetramethylene maleate)-co-(tetramethylene phthalate)] (BMPA), poly[(tetramethylene fumarate)-co-(tetramethylene phthalate)] (BFPA) and poly[(tetramethylene phthalate)-co-(tetramethylene succinate)] (BPSA). The results of the mechanical spectrometric analysis are presented as master curves by applying the time-temperature superposition principle. The WLF parameters of the cured unsaturated polyesters were determined above the glass transition temperatures. The glass transition temperatures shift to higher temperatures with increasing degree of crosslinking. The equilibrium shear storage modulus plateau changes as a consequence of the different configuration of the double bonds and the degree of crosslinking. The degree of crosslinking, nc, determined from the equilibrium shear modulus G′e, was higher than those determined from equilibrium swelling measurements, which is apparently connected with the contribution of physical entanglements.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
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