Comparative Analysis of Polyesterification Reaction on Crude and Epoxidized Neem Oil-Modified Alkyd Resin
A. U. Anya *
National Research Institute for Chemical Technology (NARICT), Zaria, Kaduna State, Nigeria
I. R. Jack
Department of Chemistry, Rivers State University of Science and Technology (RSUST), Port Harcourt, Nigeria
O. F. Osagie
Department of Chemistry, Rivers State University of Science and Technology (RSUST), Port Harcourt, Nigeria
*Author to whom correspondence should be addressed.
Abstract
A portion of neem oil was epoxidized using per acid generated in-situ. Polyesterification of crude neem oil (CNO) and epoxidized neem oil (ENO) was carried out using glycerol and phthalic anhydride to synthesize two different alkyd resins; crude neem oil modified alkyd resin (CNOMAR) and epoxidized neem oil modified alkyd resin (ENOMAR) with oil length of 64.5% each. Setting reaction temperature at 250°C, sample were withdrawn from the reaction mixture at interval of 30 min for a period of 150 min to determine the drop in acid value and was use to obtain a relationship with the degree of polymerization (DP) and extent of esterification (PA) for both resins. Minimum acid values of 13.01 mgKOH/g and 16.09 mgKOH/g were recorded after a reaction period of 150 min for (ENOMAR) and (CNOMAR) respectively. Maxima value of 4.000, (75.0%) and 3.647, (72.6%) were recorded after 150 min as average degree of polymerization (DP) and percentage extent of esterification (%PA) for (ENOMAR) and (CNOMAR) respectively. Statistical analysis using ANOVA table to compare the degree of polymerization between (ENOMAR) and (CNOMAR) gave FV=0.372 and FC= 5.530. The result of polyesterification (PA) and degree polymerization reaction (DP) for both resins reveals that (ENOMAR) has faster rate of polymerization compared to (CNOMAR).
Keywords: Alkyd resin, extent of esterification, degree of polymerization and polyesterification