A Statistical Comparison of 1,4 Cyclohexanedicarboxylic Acid, Isophthalic Acid, and Hexahydrophthalic Anhydride in Gel Coat Resin

摘要

Cycloaliphatic monomers, such as 1,4-cyclohexanedicarboxylic acid (1,4-CHDA), provide gel coat resins with an excellent balance of flexibility and hardness while enhancing weatherability by reduction of UV active aromatic diacids. The objective of this work was to compare 1,4 cyclohexanedicarboxylic acid (1,4-CHDA), isophthalic acid (PIA), and hexahydrophthalic anhydride (HHPA) in a typical gel coat formulation based on neopentyl glycol and propylene glycol. The DOE was carried out using a three components mixture design. Trends in resin processing time, MW distribution, heat deflection temperature and other relevant properties will be presented. Blister resistance, QUV-A, and Xenon Arc data will be discussed for subsequent gel coats prepared from the resins. The results of the study will provide a comparison of the advantages and disadvantages of each monomer component and blends of the three components. The effect of a vinyl ester barrier coat on gel coat weathering properties will also be investigated. Focus will be given to those property trends that exhibit the greatest differential in performance versus the traditional NPG/ISO resin.