Studies on the synthesis and curing of epoxidized novolac vinyl ester resin from renewable resource material

Sultania, Minakshi; Rai, J.S.P.; Srivastava, Deepak

doi:10.1016/j.eurpolymj.2010.07.014

Cited by 97 publications

(47 citation statements)

References 34 publications

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“…Thus, cardanol-based epoxidized novolac resin was reacted with methacrylic acid in the presence of triphenylphosphine in order to produce the cardanol-based epoxidized novolac vinyl ester resin. 145 The modification of the cardanolbased novolac resins by the epoxidation reaction with epichlorohydrin enhances the performance of such resins in various fields. 146,147 Aside from lignin and cardanol, the other terrestrial source of phenolic compounds is tannins.…”

Section: Iii1 Epichlorohydrin Synthesis Of Phenolic Epoxy Prepolymersmentioning

confidence: 99%

The use of lipases as biocatalysts for the epoxidation of fatty acids and phenolic compounds

et al. 2014

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Lipases are versatile enzymes that can be used for various kinds of biocatalyzed reactions. Owing to their selectivity and their mild reaction conditions, they can be often considered as more interesting than classical chemical catalysts. Besides their application in oil and fat processes, these enzymes have proved to be very attractive for other lipase-catalyzed reactions. This review discusses the latest results where lipases are used for the epoxidation of lipid substrates (namely fatty acids and their derivatives) and phenolic compounds. This chemo-enzymatic process involves a two step synthesis where the biocatalyst acts as a perhydrolase to produce peracids, which then act as catalysts to epoxidize double bonds. Various factors govern the efficiency of the reaction in terms of kinetics, yields and enzyme stability.These parameters are evaluated and discussed herein. (Résumé d'auteur

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Section: Iii1 Epichlorohydrin Synthesis Of Phenolic Epoxy Prepolymersmentioning

confidence: 99%

The use of lipases as biocatalysts for the epoxidation of fatty acids and phenolic compounds

et al. 2014

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“…This resin is one of the most important thermoset polymers that combine the chemical, mechanical and thermal properties of epoxy resins with the fast cure of unsaturated polyester resins (UPRs) [2][3].…”

Section: Introductionmentioning

confidence: 99%

Studies on thermal and viscoelastic properties of vinyl ester resin and its composites with glass fiber

Garay

Paese

Souza³

et al. 2015

Matéria (Rio J.)

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Vinyl ester resins are widely used in sandwich composite structures. Because of their good resistance to chemicals, flexibility and easy processing, these sandwich are extensively applied in the marine sector. These composites are typically manufactured by liquid molding processes, especially infusion. In this study, RTM light was used to inject the polymeric resin into the mold cavity, flowing in the space between the impermeable core and the mold walls, where the fibrous medium was. In this process, viscosity, gel time and curing time of the resin are very important parameters. This work addressed the curing and post-curing characteristics of a vinyl ester resin, and also the characteristics of neat and reinforced vinyl ester using dynamic mechanical analysis (DMA). The increase in shear rate did not significantly influence resin viscosity within the studied range. Differential scanning calorimetry showed the efficiency of the post-curing stage, with the decrease in residual enthalpy. With DMA, it was possible to determine gel time and gel temperature, which yielded similar values to those found by the SPI (Society of the Plastics Industry) method, indicating that the simpler SPI method can be reliably used for that.Keywords: Vinyl ester, DMA, RTM light, sandwich composites. INTRODUÇÃOVinyl ester resins (VER) result from the reaction between bisphenol-A based epoxy oligomers and unsaturated carboxylic acids, such as acrylic or methacrylic acid which provides unsaturated terminal sites [1]. This resin is one of the most important thermoset polymers that combine the chemical, mechanical and thermal properties of epoxy resins with the fast cure of unsaturated polyester resins (UPRs) [2][3].Composite materials produced with vinyl ester resins and glass fibers are widely used in marine application, such as fishing trawlers, canoes, patrol boats, mine hunters and submarine domes [4]. In many cases, sandwich composite structures are chosen and the easy processing of VER allows the use of liquid molding techniques, such as infusion and RTM light. In these processes, resin is injected into the mold cavity, flowing in the space between the impermeable core of the sandwich and the mold walls, where the fibrous medium is. Since resin flow occurs through long distances, viscosity and gel time of the resin become critical parameters.The cure of VER plays a vital role in their processing and cure kinetics studies have received much attention. Calorimetry has been used to determine the effect of the initiator concentration and oxygen on the rate of cure [5]. These resins generally contains 30-60% styrene by weight, which serves as diluents to enhance linear chain extension and to reduce viscosity of the resin, allowing for easy processing and room temperature curing [6]. Styrene also acts as a "bridge'' between chains during the cross-link process, that occurs when an initiator opens up double-carbon bonds between vinyl ester and styrene molecules, allowing these free radicals to link and crosslink, resulting in a cur...

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“…However, the values of tensile strength, elongation at break and impact strength of VEOCN sample containing styrene as reactive monomer is found to be higher than that of VEOCN sample containing MMA. This may be due to the formation of more pronounced biphasic structure during curing, where the formation of polystyrene imparts more fl exibility to the sample containing styrene 22 . During curing process, the physical state of thermoset resins changes from liquid to gel and ultimately to a glassy solid.…”

Section: Mechanical Characterization Of Veocn Samplesmentioning

confidence: 99%

Morphological, Mechanical and Physio-chemical Performance of ortho-Cresol Epoxy Novolac Based Vinyl Ester Resin

Jaswal

Gaur

2015

Polish Journal of Chemical Technology

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Vinyl ester resin (VEOCN) was prepared from o-cresol epoxy resin (EOCN) and methacrylic acid in the presence of triphenyl phosphine as catalyst and hydroquinone as inhibitor with acid value of ~ 7 mg of KOH per gram of solid. O-cresol based novolac resin (OCN), OCN based epoxy resin (EOCN) and VEOCN were characterized by Fourier transform infra red spectroscopy (FT-IR), 1 H-NMR and 13 C-NMR. The thermal and mechanical behavior of the samples prepared at 30°C from VEOCN using styrene and methyl-methacrylate respectively as reactive diluents, in the presence of benzoyl peroxide (2 phr) as initiator was studied using Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA) and Universal Testing Machine (UTM). Chemical resistance of above VER samples was also evaluated as a function of % weight loss and with the help of Scanning Electron Microscopy (SEM), upon immersing the VEOCN samples in different solutions for 90 days.

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Studies on the synthesis and curing of epoxidized novolac vinyl ester resin from renewable resource material

Cited by 97 publications

References 34 publications

The use of lipases as biocatalysts for the epoxidation of fatty acids and phenolic compounds

The use of lipases as biocatalysts for the epoxidation of fatty acids and phenolic compounds

Studies on thermal and viscoelastic properties of vinyl ester resin and its composites with glass fiber

Morphological, Mechanical and Physio-chemical Performance of ortho-Cresol Epoxy Novolac Based Vinyl Ester Resin

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