Evaluation of Suitability of Lemongrass Powder as an Alternative Antioxidant for Dry Rubber Composites

Research at a glance

Ageing of natural rubber based products leads to reduction in various properties and hence deterioration in quality of the final products. The use of antioxidants (AOs) in rubber based compounding has been introduced to mitigate this issue up to a certain level. The commercially available AOs tend to generate hazardous substances which can affect the eco systems adversely. This study was carried out to probe the possibility of using lemongrass (Cymbopogon citratus) root stem and leaf powder (LGP) as an alternative natural AO for natural rubber based dry rubber composites. Cure and ageing properties of composites containing commercially available AOs such as N-isopropyl-N’-phenyl-p- phenylenediamine (IPPD), 2,2,4-trimethyl-1,2- dihydroquinoline (TMQ) and 2-2’-methylenebis [6- (1-methylcyclohexyl)-P-cresol] (WSP) were compared with those of the composite produced with LGP. The dry rubber composite produced without any AO was used as the control. The comparison revealed that the LGP incorporated composite generates better processing safety than that prepared with IPPD and higher cure rate index than that prepared with TMQ, which are considered as ubiquitous AOs in the industry. Additionally, the former composite provided superior qualities not only with respect to cure characteristics, but also in regard to retention of tensile strength and elongation at break than the WSP incorporated composite. It can be concluded that it is possible to substitute the phenolic type AO WSP with LGP in dry rubber composites.