Studies on synthesis of modified epoxidized novolac resin from renewable resource material for application in surface coating

Abstract

Five blend samples of cardanol-based epoxidized novolac resin containing varying concentrations of carboxyl-terminated poly(butadiene-co-acrylonitrile) (CTBN) ranging between 0 and 25 wt % with an interval of 5 wt % were prepared. The epoxidized novolac resin (ECF) was synthesized from the epoxidation of cardanol-based novolac-type phenolic resin (CF) with molar excess of epichlorohydrin (i.e., about 10 mol at 120 C in basic medium). The CF resin was synthesized with a molar ratio of 1 : 0.5 of CF using dicarboxylic acid catalyst such as succinic acid at 120 C for 5 h. The pure epoxy and its blend were cured with stoichiometric amounts of polyamine curing agent. The formation of various products during the synthesis of cardanol-based novolac resin, epoxidized novolac resin, and blending of epoxidized novolac resin with CTBN have been studied by Fourier transform infrared (FTIR) spectroscopic analysis. Further, a reaction mechanism for the step-growth reaction was proposed on the basis of the results of FTIR analysis. Also, the structures of CF and ECF were proposed on the basis of the results of nuclear magnetic resonance and MALDI-TOF mass spectroscopic analysis along with gel permeation chromatographic (GPC) analysis. GPC analysis resulted in M n of 670 gmol À1 . The blend sample having 15 wt % CTBN concentration showed minimum cure time, whereas the presence of CTBN in blend systems showed marginal change in the values of DH. A clear-cut two-step mass loss in dynamic thermogravimetric trace of unmodified and CTBN-modified systems was observed. Thermal stability of the blend sample containing 15 wt % CTBN into the pure epoxy resin was the highest among all other prepared systems.

Characterization of green composites from biobased epoxy matrices and bio-fillers derived from seashell wastes

“…Different epoxidized vegetable oils (mainly epoxidized linseed oil-ELO and epoxidized soybean oil-ESBO due to their low cost) have been successfully used as thermosetting epoxy resins as coatings and polymer matrices with a wide variety of reinforcements [6][7][8][9][10]. Also, different products derived from the cashew nut shell liquid (CNSL) industry are attracting as biobased phenolic resins [11,12] and some advances in biobased unsaturated polyester resins have been done by using biobased polyols and other components [13,14] The main aim of this work was to develop a green composite from a commercial epoxy resin with more than 50% of percentage of biomass carbon content and bio-fillers derived from seashell of different bivalve mollusks collected from the seashore. The composition of the bio-fillers from seashells was determined and the effect of surface modification by silane coupling agents to provide good chemical affinity towards epoxy resin was also evaluated.…”

Influence of the Bio‐Based Epoxy Prepolymer Structure on Network Properties

“…Investigations were also performed on the synthesis of epoxides based on different carbohydrate–based monomers, such as sucrose,13 sorbitol,14, 15 maltitol,14 and isosorbide,16–18 which led to epoxy networks with interesting properties. Cardanol derived from cashew nut shell liquid was also used to prepare epoxy materials and the influence of diepoxidized cardanol on the curing kinetics of a system was studied 19–21. Epoxy prepolymers can be synthesized from isosorbide by different synthetic routes 16, 22–26.…”

Novel high glass temperature sugar-based epoxy resins: Characterization and comparison to mineral oil-based aliphatic and aromatic resins

“…Sugar is a renewable resource that has the potential to replace mineral oil in the synthesis of EPs, furthermore due to its large oversupply in the recent decades its application as base material in polymer synthesis does not compete with the food industry. Sugar based EP components can be synthesized by replacing the hydroxyl groups of sugar structured molecules as cardanol [27][28][29], sucrose [30,31], maltitol, sorbitol [32] and isosorbide [33][34][35][36] with oxirane functions. With the mixture of a novel synthesized cardanol based novolac-type phenolic resins and polybutadiene liquid rubber (CTPB) tensile strength improvement and higher thermal stability could be achieved with increasing CTPB-content.…”

“…[27]. With poly(butadiene-co-acrylonitrile) (CTBN) the tensile strength decreased, but with 15 mass% CTBN-content, the impact strength increased [28,29]. Cured epoxy allyl sucrose (EAS) and epoxy crotyl sucrose (ECS) were compared to DGEBA by Pan et al [30].…”