Development of castor oil based bio-binder for composite materials

Abstract

The development of polymers in various industries has been deteriorating due to the depletion in fossil fuels and environmental concerns such as the effect of greenhouse gases, global warming and increasing population. However, vegetable oils have emerged as a worthy replacement for fossil fuels. The need to use non-edible oils is recommended for industrial processes to reduce the dependency on edible oils and hence increasing food security. This investigation uses an affordable process to develop bio-binders for composite materials using non-edible oil produced from castor seed. The oil was first extracted from the castor seeds using the Soxhlet extraction set-up, purified and then process to yield castor oil-based bio-binders using Polycondensation, Epoxidation and Ozonolysis methods. Polycondensation is a three step process whereby; the first step is the synthesis of the N, N-Bis (2-hydroxyethyl) Castor Oil Fatty Amide (HECA), followed by the synthesis of the Castor Oil Polyesteramide (CPEA) and lastly, the synthesis of Castor Oil Polyurethane -esteramide (UCPEA). The polycondensation process was monitored by TLC until the production of the polyurethane, and temperatures ranged from 120 –250 °C at various stages of the process. The polyurethane peak was observed using FTIR at 1618 cm−1and 1459 cm−1. Ozonolysis was a two-step process whereby firstly it was the synthesis of the polyols by using ozone at very low temperatures (-30 to -40 °C). This was followed by the second step which is the synthesis of the polyurethanes from the polyols (70 –110 °C). The ozo peak was observed using FTIR at 1269 and 875 cm-1. The Epoxidation catalyst was synthesized from of tungstic acid and hydrogen peroxide at 50 -60 °C. The Epoxidation process temperature varied between 60 and100 ᵒC while varying the catalyst loading and the reaction time. The epoxy peak was also observed using FTIR at 830 cm-1