Abstract

Physico-Mechanical Properties and Water Absorption Behavior of Natural Rubber Vulcanizates Filled With Sawdust

Author(s): Amoke A, Ogbobe O, Tenebe GO, Ichetaonye SI and Ayo MD

The physical properties and water absorption behavior of vulcanized natural rubber filled with sawdust (of 60μm particle size) were investigated and compared with carbon black filled vulcanizates. The sawdust was characterized in terms of moisture content (9.80%), iodine absorption number (72.40), pH (6.40) and compounding was done at varying filler loadings (10 pphr, 20 pphr, 30 pphr and 40 pphr) using two roll mill. The results showed that incorporation of sawdust into the vulcanized natural rubber generally increased the tensile strength, tensile modulus, and hardness and abrasion resistance of the composites produced, whereas the elongation at break and compression set of composites decreased as the filler loadings increased. The results obtained from vulcanized natural rubber were compared with vulcanized rubber filled with carbon black filler. It was observed that vulcanized natural rubber filled with carbon black filler showed better mechanical properties than vulcanized natural-sawdust composite in all the filler loadings. In addition, the effects of these fillers on the end-use properties such as water absorption were examined. The results showed that as the filler loadings increase, the water uptake in sawdust filled vulcanizates increased to 5.00%, 8.40% and 9.60% for 20 pphr, 30 pphr and 40 pphr respectively showing high water absorption, while the control and carbon black filled vulcanizates had low water uptake of 0.70% for control, 2.10%, 1.30%, 0.66%, and 0.65% for 10 pphr, 20 pphr, 30 pphr, and 40 pphr respectively for carbon black filled vulcanizates.