Preparation of epoxy adhesives from cashew (Anacardium occidentale L.) nut shell liquid

Date

11-1997

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Milagros M. Peralta

Abstract

Cashew nut shell liquid (CNSL) was extracted from cashew nuts shells using several methods: Soxhlet extraction (23-27 % recovery), base extraction (17 %) and supercritical fluid extraction (16 % recovery). Among the methods tested, Soxhlet extraction using petroleum ether gave the best yields of the dark brown viscous CNSL. CNSL was reacted with epichlowhydrin (1:10 !not) in the presence of base to give an epoxy resin prepolymer with an average molecular weight estimated at 460.67 g/mol by end group analysis. The IR spectrum of the resulting polymer confirmed the presence of the phenolic ring, polyhydroxyl and epoxy groups. The epoxy prepolymer was subsequently reacted with various curing agents to determine the formulation that would be comparable to commercial bisphenol A-based epoxy adhesives in strength. The curing agents that were used included the following: N,N'-dimethylaniline, diethylamine, ethylenediamine, nialonic acid, adipic acid, maleic anhydride and plithalic anhydride. Among the adhesives prepared, the adhesive prepared using maleic anhydride as the curing agent was found to be the strongest. Results showed that this adhesive was comparable to the commercial formulation in terms of mechanical strength. Using an Instron Universal Testing Machine, stress at break fir the best formulation was found to be 3.475 MI'a compared with 4.2475 lvIl'a for the commercial resin. Results of this study show that cashew nut shell liquid can be used as a cheaper alternative to the more costly, imported bisplienol A in commercial epoxy formulations.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 1997 C4 M36

Document Type

Thesis

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