ENHANCED COATING PROPERTIES OF POLYURETHANES DERIVED FROM GOSSYPIUMHIRSUTUM L. SEED OIL

Abstract

Polyurethanes (PUs), are measured as one of the mainly used synthetic polymer families in the world. At the industrial scale, PUs were obtained through a polycondensation reaction of polyisocyanate with polyol. Nowadays bio-based polyurethanes have been occurred a large attention. These biobased PUs could replace petroleum-based polyurethanes in industry and particularly as coatings, binders or compounds for automotive and aircraft industries. This large application can be described due to their good mechanical and thermal properties, including abrasion resistance, high toughness as well as chemical resistance. Gossypiumhirsutum L. (cotton) seed oil is one of the dominant vegetable oils and one of the earliest seeds used to produce oil because of its ample supply, lower price than competing oils and biodegradability. This present work succeeded with the improved properties PUs using, the bio-resource, Gossypiumhirsutum L. (cotton) seed oil. Through in-situ epoxidation and hydroxylation, the cottonseed oil was transformed into a polymerizablepolyol. This hydroxylated cottonseed oil was polymerized with hexamethylenediisocyanate at pre-studied NCO-to-OH ratio to furnish enhanced propertied polyurethanes. Analytical methods such as FT-IR and 1H-NMR, and physical properties of viscoelastic behaviours, tensile strength, modulus, % elongation, specific gravity and mechanical ability were employed. The individual characterisations of FT-IR and 1H-NMR characterizations strongly supports the presence of hydrolysed cottonseed oil and polyurethane formations. In addition to that the higher acid value and hydroxyl values such as 9.86 and 166.2 respectively reflects the excellent formation of hydroxylated cottonseed oil. The static mechanical properties of synthesised polyurethane at optimum NCO-to-OH ratio obtained as: tensile strength ( )-15.29 MPa, modulus (E)-4.49 MPa and %elongation as 93.47 (%E). These properties reinforced the polyurethane matrix and make it more compact and stiffer.