Temperature, conversion, and phase separation profiles during mold cure of a modified vinyl-ester resin

Article

Authorship

SCHROEDER, WALTER FABIAN ; Auad, M. L. ; SOULE, EZEQUIEL RODOLFO

Date

2008

Publishing House and Editing Place

John Wiley & Sons Inc

Magazine

POLYMER ENGINEERING AND SCIENCE, vol. 48 (pp. 52-61) John Wiley & Sons Inc

Summary Information provided by the agent in SIGEVA

In this work, morphological differences over the thickness of modified vinyl-ester (VE) samples are studied. A thermodynamic analysis based in the Flory-Rehner theory is proposed to evaluate the spinodal decomposition temperature evolution during the reaction. This model takes into account changes in (styrene-co-VE) copolymer composition and binary interaction parameters with conversion. Then, from the energy and mass balance equations, temperature and conversion profiles over the thickness as ... In this work, morphological differences over the thickness of modified vinyl-ester (VE) samples are studied. A thermodynamic analysis based in the Flory-Rehner theory is proposed to evaluate the spinodal decomposition temperature evolution during the reaction. This model takes into account changes in (styrene-co-VE) copolymer composition and binary interaction parameters with conversion. Then, from the energy and mass balance equations, temperature and conversion profiles over the thickness as a function of reaction time are calculated. Combining these profiles with the proposed thermodynamic model, spinodal decomposition conversion graphs are constructed. To verify model predictions, a synthesized VE resin was modified with 7.5 wt% of poly(butadiene-co-acrylonitrile) vinyl terminated (VTBN) elastomer and then cured in molds of 3, 7, 12, and 20 mm thickness at 80°C. Fracture surfaces were observed by scanning electron microscopy showing morphological differences over thickness, which can be explained from the results obtained from the simulation.