Abstract:
In pursuit to develop sustainable, eco-friendly and high-performance toughened epoxy materials, a green reactive monomer,
epoxy methyl ricinoleate (EMR) was synthesized through transesterifcation of epoxidized castor oil (ECO). Both ECO and
EMR were used as co-monomers with petro based epoxy resin at 10, 20, and 30% and cured with triethylenetetramine (TETA)
to achieve toughened samples with moderate stifness. Compared to neat epoxy, tensile strength of EPECO20 and EPEMR20
co-polymeric systems increased by 21.6% and 30% along with enhancement in impact strength to the tune of 24.4% and
39.4% respectively. Non-isothermal kinetic methods, Iso-conversional method and autocatalytic model were used to fnd
curing kinetic parameters of the optimized EPECO and EPEMR copolymer system. The efects of ECO and EMR on curing
kinetics and thermo-physical properties of TETA cured epoxy has been studied in order to control the curing reaction and
achieve adequate properties for structural applications, which are not explored so far. The inclusion of ECO as copolymer
resulted in the increase of activation energy (Ea) of curing by 10.9%, wherein EMR incorporation reduced the Ea value by 5%
because of its low viscosity, better resin difusion and reactivity. The water difusion coefcient is increased with increase in
bio-resin content and water absorption through these samples is found to be a reversible process. The dynamic mechanical
analysis (DMA) showed a reduction in glass transition temperature (Tg) with the improved damping ability of copolymers
due to segmental mobility of the fexible aliphatic chains of bio-resins. TGA study revealed the reduction in decomposition
rate on addition of bio-monomers without much change in derivative peak temperature. These greener materials can fnd
space in structural composites applications, being eco-friendly and sustainable.
