ptimization of Novolac Resin Modified with Cashew Nut Shell Liquid by Response Surface Methodology

摘要

The major novolac resin worldwide used in molding powder is phenol formaldehyde (PF) resin. The raw material for this kind of resin is derived from petroleum oil. Because of rising prices of crude oil and the scarcity of petroleum products, their replacement by natural resource-based raw material has become a necessity. It was found that up to 40 wt % of phenol can be substituted by lignin to give a modified novolac resin with comparable properties compared to that of commercial PF resin. The latest software design-Expert 7.1 was used to design and analyze experiment result. The effects of pH, CNSL, additive and high temperature reaction time(HTRT) were investigated by Box-Behnken design, a relation model of softenting point test was established. The optimum condition was obtained by response surface methodology(RSM) as follows: pH 1.8, CNSL 41.6g，additive 7.3g，HTRT 3.5h. Owing to an organic additive, the replacement of CNSL (40%) for phenol is twice amount of industrial production (15-20%). The obtained novolac resin has comparable properties(e.g. softening point 95～99 ℃).