Effect of modified keratin from renewable sources on composites properties of synthetic isoprene rubber

Abstract

The present conducted research focused on elastomeric materials containing reinforcing modified keratin fibers in their composition. The applied keratin was modified by solvolysis reaction to obtain the product in the form of a hydrolysate. Then, the hydrolysate was modified by the addition reaction of keratin adduct with a plasticizer—technical stearin is commonly used in processing elastomers. The keratin hydrolysate adducts were used in a different weight proportion in the composites in which the carrier was isoprene rubber (IR; Cariflex 305). The obtained composites (rubber Cariflex composites (RC)) were subjected to a series of tests aimed at understanding the structure and interactions between biopolymers and other components of elastomeric mixtures. Mechanical properties, including hardness, the cross-linking density, and thermo-oxidative aging were investigated. Microbiological tests were carried out, which in turn allowed to determine the effect of introduced keratin in a modified hybrid form, to the elastomeric matrix. The test results indicate a significant improvement of some properties, especially when using 10 parts by weight of keratin adducts introduced into 100 parts by weight of IR rubber.