Effect of dispersion preparation technique of calcium carbonate (CaCO3) fillers on mechanical properties of natural rubber (NR) latex films

Abstract

The calcium carbonate fillers are added to natural rubber (NR) latex compound in order to reduce the cost of the compound. The CaCO3 powder need to be prepared in dispersion form before added into the latex medium to avoid the instability of the NR latex compound. The ball milling is a conventional dispersion preparation technique used to prepare the dispersions for powder ingredients for latex compound. The combination of ultrasonic and ball milling technique has shown the reduction in particle size of the resulted dispersions. In this study, effect of ultrasonic parameters (duration, speed, concentration) together with ball milling technique (duration, speed) was carried out. The effect of dispersion preparation technique on CaCO3 particle was examined by means of particle size and zeta potential measurement. In addition, the morphology of the CaCO3 particle also were investigated by using transmission electron microscopy (TEM) and the mechanical properties of NR latex film were investigated based on tensile and tear test. The results showed that a combination of both ultrasonic and ball milling has produced smaller particle size. It was also found that, smaller size CaCO3 particles greatly influenced the mechanical properties of calcium carbonate/natural rubber latex (CaCO3/NRL) films. This is due to the ability of the CaCO3 to be homogeneously dispersed in NR latex compounds which able to improve the mechanical properties of the NR latex films together as well as to reduce the cost of the compound.