Comparative Analysis of Polyesterification Reaction on Crude and Epoxidized Neem Oil-Modified Alkyd Resin

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 Setting reaction temperature at 250°C, sample were withdrawn from the reaction mixture at interval of 30 min for a period of 150 min to determine the drop in acid value and was use to obtain a relationship with the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).