Effect of monomer content and hardener on the thermomechanical properties of some epoxide resins

• Published in: Journal of materials science letters 1987-03, Vol.6 (3), p.337-342
• Main Author: HANCOX, N. L
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Mechanical properties; Physical properties; Polymer industry, paints, wood; Properties and testing; Technology of polymers
• ISSN: 0261-8028; 1573-4811
• DOI: 10.1007/BF01729346

An assertion that the mechanical properties of a cured diglycidyl ether of bisphenol A (DBEBA) resin would be improved as the monomer content is increased because the cross link structure and bond length would be more uniform is tested. Four unreinforced resins (Shell 828, 828 EL, and 825 and Ciba-Geigy LY1805) cured with amine and anhydride hardeners were prepared. In the amine-cured system, an increase in the monomer content caused a decrease in the room-temperature tensile strength and an increase in the glass transition temperature (T sub g ). For the anhydride-cured system, increasing monomer content caused an increase in room-temperature tensile strength and a decrease in T sub g . The results for the amine-cured material were consistent with an increased cross-link density. The observations on anhydride-cured systems may have been due to decreased bonding because of the reduction of hydroxyl groups leaving some hardener unreacted. The unreacted hardener might have acted as a plasticizer and so led to improved tensile strength as the monomer content was increased. 5 ref.--D.M.Y.