Characteristics of maleic anhydride-modified polystyrene and natural rubber blends containing “Talang” bamboo powder as sound damping material

In this work, polymer composite materials were prepared based on natural rubber (NR), polystyrene (PS) and Talang bamboo (Schizostachyum brachycladum) powder (TBP) using reflux technique in xylene solution under mechanical stirring in the presence of maleic anhydride (MA as modifier) and benzoyl peroxide (BPO as initiator). According to our previous works weight ratio of components: PS/NR/MA/BPO was fixed at: 40/60/10/1php (php: per hundred polymer), whereas that of TBP (particle size 80 mesh) were varied at: 70, 60, 50 and 40 php. After evaporation and drying under vacuum at 60°C to constant weight, the mixtures were pressed at 170°C to 3-point bending test specimens (ASTM D790-02). It was found that at optimum composition (weight ratio of polymer matrix to TBP: 60:40), the modulus elasticity (MoE) was 132.8 MPa and modulus of rupture (MoR) was 9.6 MPa. This is supported by the presence of MA modifier, proved by FTIR analysis of the specimen after exhaustive washing in acetone-methanol solvent, which showed absorption peak of carbonyl (>C=O) group at 1709 cm-1, and function as coupling agent. SEM micrograph of the optimum specimen surface also showed homogenous distribution of the TBP. Whereas its DSC analysis showed lower decomposition temperature (345°C) compared to that of corresponding control without TBP (445°C). The presence of Talang bamboo powder increased sound absorption coefficient (α) of the composites.