Characterization and properties of PP/NBRr/Sago starch composites with and without NaOH treatment

Abstract

Sago starch is an alternative material in developing cheap degradable materials since it is environmental friendly, biodegradable and also abundant in supply. In addition, incompatibility between polymer matrix and natural filler causes poor interfacial adhesion in the polymeric composites. In this research, sago starch is used as filler in polypropylene and recycled acrylonitrile butadiene rubber (NBRr) matrices. Surface modification using sodium hydroxide (NaOH) was carried out to modify starch properties. The mechanical properties, chemical properties and swelling behaviour of the PP/NBRr/sago starch composites with and without treatment of sodium hydroxide were investigated. The composites were prepared by using heated two roll mill machine at temperature of 180 °C with speed of 15 rpm for 9 minutes to mix the materials and then compressed using hot press to produce 1 mm thin sheet plate before cutting it into dumbbell specimens for analysis. The result obtained showed composites with NaOH treatment have better tensile strength, Young’s Modulus and help in reducing swelling absorption percentage of water, oil and toluene. FTIR results showed the intensity of OH groups was improved and formation of chemical bonding between sago filler and C-O-C in the presence of NaOH treatment.