Sulfur-to-canola oil (S/O) ratio and curing conditions on the biopolymer (BP) properties

Abstract: Inverse vulcanization emanating from elemental sulfur (S) and unsaturated cross-linkers is used to form biobased polymers that can be used for various environmental remediation measures. In this study, canola oil and waste sulfur were used to synthesize an optimum polymer. The effects of sulfur to oil ratio (10:100, 12.5:100, and 15:100) and curing conditions, such as temperature (120-180 °C and curing time (6-24 h) on the biopolymer properties were studied and analytically characterized. The hardness of the biopolymer was assessed using durometer reading for each condition. The results showed that 15:100 ratio of sulfur to canola oil provides the most ideal biopolymer, while curing at 180 °C for 12 h is required at least. The elemental mapping at this optimum condition showed that S is engrained uniformly in the polymer. The polymer exhibited good hydrophobicity with a contact angle at 120° and was not soluble in water, whereas it is soluble in acetone and toluene. These results show a promising application of this biopolymer for the encapsulation of hazardous materials.

Keywords: biopolymer, vegetable oil, curing condition, hydrophobicity, hardness