Comparative Studies of Oil-Modified Alkyd Resins Synthesized from Epoxidized and Crude Neem Oil

I R Jack

doi:10.11648/j.ajac.20160404.11

Abstract

Two different alkyd resins; epoxidized neem seed oil-modified alkyd resin (ENOMAR) and crude neem seed oil-modified alkyd resin (CNOMAR) with oil-length of 64.5% each were synthesized. A portion of neem oil was epoxidized at 50°C using per-acid generated in-situ. The (ENOMAR) and (CNOMAR) were prepared using glycolysis and poly-condensation methods. Methyl ethyl ketone peroxide (MEKP) and cobalt naphthalate in toluene were employed as the driers. The physicochemical analyses of the synthesized resins were investigated. Also, minimum drying and set to touch time was recorded at 15hrs, 9hrs and 17hrs, 10hrs for (ENOMAR) and (CMOMAR) respectively at temperature of 120°C on exposed for 120min. Both resins show good resistance in 10% HCl and distilled water. (CNOMAR) shows relatively fair resistance in 1%NaCl while (ENOMAR) has a poor resistance in the brine solution. FT-IR results shows a broad and sharp peaks at 1732cm-1, 2928cm-1 and 3465cm-1 for (ENOMAR) and two broad peaks at 1734cm-1, and 2927cm-1 for (CNOMAR). Statistical analysis from ANOVA table comparing the drying time between the two resins gave Fv =0. 327 and Fc = 5. 990. Assessments of the properties show that epoxidized neem oil modified alkyd resin (ENOMAR) has better film properties compared to crude neem oil modified alkyd resin (CNOMAR).

Highlights

Alkyd resins are tough resinous polyester polymer prepared by condensation polymerization of polyhydric alcohol and polybasic acid modified with fatty acid or their glyceride
The aim of the present work is to synthesize alkyd resin with an improved performance quality from neem oil; the increase in demand for vegetable oil with high unsaturated content like linseed oil, cotton seed, soybean oil etc in alkyd resin production necessitated to the need for an alternative
The produced hydro-peroxides decompose to create alkoxy and hydroxyl free radicals and these free radicals react with each other to form cross-links [2, 7 & 9]. This will change the drying time characteristic and add value to it Assessments of the properties show that epoxidized neem oil modified alkyd resin (ENOMAR) has improved properties compared to crude neem oil modified alkyd resin (CNOMAR)

Summary

Introduction

Alkyd resins are tough resinous polyester polymer prepared by condensation polymerization of polyhydric alcohol and polybasic acid modified with fatty acid or their glyceride. Alkyd resin was defined by [5] as the products of poly-condensation reaction between polybasic acid and polyhydric alcohol modified with fatty acid or drying oil. It has been reported by [11], where vegetable oil is partially replaced in alkyd synthesis. Alkyd resin contain some components made up of petroleum based chemical, but are known as a green polymer as reported by [13] The resins contribute about 70% to the conventional binders used in surface coating.

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