Studies on Microbial Degradation of Natural Rubber Using Dilute Solution Viscosity Measurement and Weight Loss Techniques

Abstract

Reduction of molecular weight of rubber polymers for easy absorption of compounding ingredients is critical in every rubber compounding operation. Yet, rubber mastication which is the current practice of achieving this is expensive, requiring high energy and equipment cost. To address this problem, microbial degradation of natural rubber (NR) and waste rubber tire (WRT) by Nocardia sp. strain 385A was studied using dilute solution viscosity measurement and weight loss methods. Solutions of NR and WRT in toluene were inoculated with the microbes (Nocardia sp. strain 385A) and kept in incubator. Incubation period varied between 0 to 10 weeks. The results obtained show that NR and WRT were mineralized and degraded by the microbes. Intrinsic viscosity values of both NR and WRT decreased with increasing period of incubation, indicating that degradation increases with increase in the incubation period. For the incubation periods investigated, WRT produced higher intrinsic viscosity values than NR due to the inhibitory effect of additives present in WRT to microbial degradation. Equivalent reduction in molecular weight obtained by rubber mastication technique was achieved by microbial degradation after 10 weeks incubation period. Rubber degrading bacteria can be useful for the disposal of discarded rubber products

Development and Characterization of Polymer Eco-Composites Based on Natural Rubber Reinforced with Natural Fibers

“…Biodegradation or “biotic degradation” is basically a chemical degradation of materials caused by the biological decomposition action of microorganisms such as bacteria, fungi and algae [ 20 , 21 ]. The use of microorganisms for degradation of waste rubber products, as mentioned in many previous studies, is clear evidence of the power of those microorganisms in attacking the structure of natural rubber and breaking down its chains [ 22 , 23 , 24 ].…”

Microbial Degradation of Rubber: Actinobacteria

“…The addition of a starch component to the incubation media also improved degradation. The starch is metabolized first and acts as a growth substrate for rubber degrading bacteria, to increase initial bacterial populations rapidly, and subsequently the rate of NR degradation [ 127 , 128 , 129 , 130 , 131 ].…”

Properties Characterization of Vulcanized Natural Rubber Filled with Uncarbonized Particulate Cow Bone

“…The agricultural wastes that have been used and reported include milled coconut fibre (Egwaikhide, et.al., 2007), seed shells of cherry (Osabohien and Egboh, 2007), cocoa pod husk, rubber seed shell, rice husk and palm kernel shell (Ogbeifun, et.al., 2010), carbonized bagasse (Osarenmwinda and Abode, 2010), snail shells (Igwe and Ejim, 2011), carbonized groundnut shell (Ayo, et.al., 2011), carbonized cassava peel (Ugbesie, et.al., 2011), bamboo fibre (Onyeagoro, 2012), defatted rice bran (Moonchai, et.al., 2012), carbonized coir (Aguele and Madufor, 2012), carbonized and uncarbonized dikanut shell pericap (Ekabafe, et.al., 2012), maize stalk (Chigondo, et.al., 2013), carbonized palm kernel shell husk (Egwaikhide, et.al., 2013).…”