Optimization tensile properties of sodium bicarbonate natural rubber composite / Nur Fatnin Ayunie Abdull Rahim

The main aim of this study was to analyze the effect of sodium bicarbonate on tensile properties and morphological of natural rubber (NR) compounds in the curing time range of 1, 3, 5, and 10 minutes. The NR was mixed with fixed amount of sodium bicarbonate (SB) which is 2.5 phr by using the two-roll mill. The NR composite was vulcanised at different curing times which is 1, 3, 5,and 10 minutes at constant temperature 150 °C in the oven. The mechanical properties of the NR composite were investigated in term of tensile properties according to ASTM D412 by using Universal Testing Machine (INSTRON). The result indicates that tensile strength, elongation at break of the NR composite increase at 3 minutes of curing time and decrease at futher curing time. LCD Digital Microscope (CELESTRON) was used to evaluated the morphology of the NR composite to determine the porosity produced from the decomposition of sodium bicarbonate. The observation indicate that the pore size increases as the curing time increases.