Eco‐friendly cardanol‐based phenalkamine cured epoxy‐cenosphere syntactic foams: Fabrication and characterisation

Abstract

The performance of epoxy/cenosphere syntactic foams cured using phenalkamine (PA) were analyzed and characterized. The PA system was found to cure faster at room temperature, had lower density, and lower water absorption values. The thermogravimetric analysis result implied higher thermal stability. The cure studies using DSC inferred faster cure reaction in the ambient temperature conditions. The compression studies confirmed that unlike the epoxy system based on conventional triethylenetetramine curative, PA‐based system did not undergo brittle failure. This was also confirmed with the scanning electron microscope images. Dynamic mechanical analysis inferred the glass transition temperatures (Tg) as 81.4°C. The specific modulus and specific strength were higher for 40% cenosphere loading in PA‐based syntactic foams. As the need for light weight core materials is continually increasing, there is a great possibility for the utilization of this novel bio‐based curing agent to produce sustainable products. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44189.

Development of toughened bio‐based epoxy with epoxidized linseed oil as reactive diluent and cured with bio‐renewable crosslinker

“…This resulted in production of flexible cross‐links which degrades at higher temperature. Similar findings have been reported previously by Kaur et al…”

“…The phenolic hydroxyl groups present in PKA act as catalyst and enabled fast curing of epoxy through opening of its epoxide ring. The first exothermic peak in the range of 30 to 190°C signifies the ring opening reaction of epoxy with the amine group of PKA . This major peak temperature of curing shifted to higher values on addition of ELO bio‐resin due to retardation in curing caused by the long chain triglycerides.…”

“…The first exothermic peak in the range of 30 to 190°C signifies the ring opening reaction of epoxy with the amine group of PKA. 30,33 This major peak temperature of curing shifted to higher values on addition of ELO bio-resin due to retardation in curing caused by the long chain triglycerides. Further, multiple secondary epoxides exist in ELO molecule, which are in proximity along the same glyceride chain, experience greater steric hindrance, and require higher energy to react.…”

“…The aromatic ring present in PKA provides chemical resistance, while the alkyl side chain imparts hydrophobicity, flexibility, and long pot life. A long unsaturated aliphatic chain and aromatic moiety gives excellent balance for this raw material to be considered in polymer formulation . Many researchers have developed toughened bio‐epoxy blends using epoxidized oils as secondary component or as reactive diluent while curing with petro‐based amine and anhydride‐based curing agents .…”

“…A long unsaturated aliphatic chain and aromatic moiety gives excellent balance for this raw material to be considered in polymer formulation. [25][26][27][28][29][30][31] Many researchers have developed toughened bio-epoxy blends using epoxidized oils as secondary component or as reactive diluent while curing with petro-based amine and anhydride-based curing agents. [8][9][10][11][12][13][14][15][16][17][18][19][20][21] Based on author's knowledge, no work has been reported on ELO-based bio-epoxy blends using bio-renewable PKA as curing agent.…”