Fatty Acid-Based Comonomers as Styrene Replacements in Soybean and Castor Oil-Based Thermosetting Polymers

In this study, a fatty acid-based comonomer is employed as a styrene replacement for the production of triglyceride-based thermosetting resins. Styrene is a hazardous pollutant and a volatile organic compound. Given their low volatility, fatty acid monomers, such as methacrylated lauric acid (MLA), are attractive alternatives in reducing or eliminating styrene usage. Different triglyceride-derived cross-linkers resins were produced for this purpose: acrylated epoxidized soybean oil (AESO), maleinated AESO (MAESO), maleinated soybean oil monoglyceride (SOMG/MA) and maleinated castor oil monoglyceride (COMG/MA). The mechanical properties of the bio-based polymers and the viscosities of bio-based resins were analyzed. The viscosities of the resins using MLA were higher than that of resins with styrene. Decreasing the content of MLA increased the glass transition temperature (T-g). In fact, the T-g of bio-based resin/MLA polymers were on the order of 60 degrees C, which was significantly lower than the bio-based resin/styrene polymers. Ternary blends of SOMG/MA and COMG/MA with MLA and styrene improved the mechanical properties and reduced the resin viscosity to acceptable values. Lastly, butyrated kraft lignin was incorporated into the bio-based resins, ultimately leading to improved mechanical properties of this thermoset but with unacceptable increases in viscosity. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 1000-1010, 2011