MODIFICATION AND APPLICATION OF STARCH IN NATURAL RUBBER LATEX COMPOSITES

ABSTRACT This study presents a review of recent studies on starch-filled NR latex composites. Starch is a renewable source of material for fillers in NR latex compounding to obtain composites with multifunctional properties for selected applications. However, starch is a non-reinforcing filler due to its large particle size. The compatibility of NR and starch is another significant issue during the processing of starch-filled NR latex composites due to the nature of both materials. However, based on our research work, a fine dispersion of starch in the rubber matrix can improve the properties of NR latex composites. A good starch dispersion can be achieved through modifications, such as physical or chemical treatments. These treatments include the ball-milling process, ultrasonic process, use of coupling agents, esterification, etherification, and graft copolymerization. The various processing methods of these composites are discussed, specifically pre-vulcanization, latex co-coagulation, and in situ polymerization process. The successful modifications of either micro- or nano-starch will improve the compatibility with hydrophobic NR matrix, thereby increasing the mechanical properties of the resulting composites. The potential of starch as a biodegradable filler for NR latex and the interparticle interaction of starch-filled NR latex composites are also discussed.