New insights into the curing of epoxidized linseed oil with dicarboxylic acids

Abstract

The effect of systematically increasing chain length of a series of linear α, ω-dicarboxylic acids (DCAs) from C6 to C18 diacids and a cyclic diacid, Pripol 1009F, on thermal and mechanical properties of the resultant epoxy thermosets derived from epoxidized linseed oil (ELO) are reported. Different techniques including differential scanning calorimetry (DSC), solvent extraction, FT-IR, NMR, dynamic mechanical analysis (DMA), tensile tests and thermogravimetric analysis (TGA) are used in this study. The results indicated that the obtained epoxy resins were highly crosslinked polymers with only a small fraction of low molecular weight soluble materials. The glass transition temperature (Tg), tensile strength, Young's modulus, elongation at break and toughness decreased while the thermal stability increased with respect to increasing chain length of DCAs. Interestingly, strain hardening was only observed for adipic acid (C6) sample for which the best mechanical properties observed.A systematic study of the synthesis and characterization of epoxy thermosets derived from ELO cured with different DCAs in the presence of DMAP at 160 o C for 1 h.

Metathesis Curing of Allylated Lignin and Different Plant Oils for the Preparation of Thermosetting Polymer Films with Tunable Mechanical Properties

“…As expected, the increase of oil content leads to poor tensile strength and Young's modulus due to the increasing free volume from the triglyceride chains. The dimensions of the Young's modulus and tensile strength and the tendency to increased values with shorter aliphatic chain or more rigid structures, are in agreement with published plant oil‐based epoxy thermosetting networks . No tendency is observed for the elongation at break.…”

Development of completely bio‐based epoxy networks derived from epoxidized linseed and castor oil cured with citric acid

“…Thus, it is of great importance to utilize eco‐friendly curing agent preferably derived from renewable‐based resources to substitute petro‐based resources for producing next‐generation bio‐based epoxy networks . In this context, different bio‐derived carboxylic acids have been used, by several researchers in the past, as curing agents to develop both petro‐based and bio‐based epoxy products, with and without use of catalyst …”

“…The results revealed that CA cured bioepoxy showed higher mechanical properties than tartaric acid cured epoxy, and also the bio‐based epoxies exhibited good thermal stability. Ding et al studied the effect of different bio‐derived dicarboxylic acid‐based curing agents with DMAP catalyst on the thermal and mechanical properties of ELO‐based thermoset . Ma et al developed naturally occurring acid cured highly functional bio‐based epoxidized sucrose soyate with higher excellent mechanical and thermal properties and also used different solvents to study the effect on the properties of completely bio‐based epoxidized sucrose soyate cured with CA and DL‐malic acid.…”

Rational design of sustainable polyurethanes from castor oil: towards simultaneous reinforcement and toughening

“…Inexpensive vegetable oils, with various functional groups such as C=C double bond, ester, hydroxyl and epoxy groups depending on the origins, are thought as the ideal alternatives to fossil resources in production of novel sustainable polymers [7][8][9]. It is noted that the sustainable polymers synthesized directly from vegetable oils usually show poor mechanical performance leading to limited application [10][11][12]. Although high performance polymers such as polyamides, polyesters and epoxy thermosets can be prepared from monomers derived from vegetable oils through well-designed chemistry techniques, the conversion of vegetable oils to monomers increases the cost of the resultant materials inevitably [3,7,13].…”