Castor-Oil-Modified Epoxy Resins as Model System of Rubber-Modified Thermosets. 3. Use of Nucleating Agent to Modify the Particle-Size Distribution

ROXANA A RUSECKAITE; DIANA P. FASCE; ROBERTO J.J.WILLIAMS

POLYMER INTERNATIONAL

Wiley

Año: 1993 vol. 30 p. 297 - 300

0959-8103

Phase separation during polymerization was produced in a model system consisting of a diepoxide based on the diglycidyl ether of bisphenol A (DGEBA), ethylenediamine (EDA), and a 15% mass fraction of either pure castor oil (CO) or a 95:5 mass ratio of CO and a polyester (PE) based on CO and oxalic acid. PE acted as a nucleating agent, leading to a significant decrease in the concentration of dispersed-phase particles and the appearance of a fraction of large particles. Unimodal particle-size distributions turned into bimodal distributions when adding PE, but the total volume fraction of dispersed phase remained constant. The addition of nucleating agents may be useful to develop formulations with optimum particle-size distributions for toughening purposes