Effects of inhibitor and cure promoter on unsaturated polyester cure and mechanical properties

• Published in: Journal of materials science letters Vol. 15; no. 16; pp. 1460 - 1462
• Main Authors: GROHENS, Y, TOUYERAS, F, GEORGE, B, VEBREL, J
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer Academic Publishers 15.08.1996
• Subjects: Applied sciences; Chemical properties; Exact sciences and technology; Polymer industry, paints, wood; Properties and testing; Technology of polymers; Property composition relationship; Curing(plastics); Ester polymer; Mechanical properties; Inhibitor; Hardener; Unsaturated polymer
• ISSN: 0261-8028; 1573-4811
• DOI: 10.1007/BF00275306

The effect of inhibitor and cure promoter on the kinetics of styrene conversion during unsaturated polyester (UPE) cure was studied by viscosimmetric gel-time measurements. The purpose was to optimize the UPE room-temperature cure formulations for canoe manufacture. UPE resins without fibers were prepared from maleic anhydride or orthopthalic anhydride and propylene glycol. The inhibitors added were benzoquinone (BQ), di-tert.-butyl hydroquinone (DTBHQ), and tert.-butylcatechol (TBC). Two methylethylketone peroxides were used as free-radical initiators and cobalt octoate was used as cure promoter. The concentration and type of inhibitor were found to affect gelation significantly. Higher inhibitor concentrations increased the gelation time which finally affected the mechanical properties of the cured resin, as measured by three-point bending test. A BQ-DTBHQ mixture was found to be the best inhibitor mixture that can support longer storage of UPE formulations.