Effect of inorganic fillers on natural rubber latex foam vulcanisates

The focus of this study is on the evaluation of the effect of different types of inorganic fillers on the different major properties of natural rubber latex (NRL) foam vulcanisates. The mechanical and chemical properties of filled NRL foam were evaluated and compared with unfilled vulcanisate as per BIS standards IS 1741:2019 and IS: 6664 (1992) RA 2004 specification. The different fillers at various loadings selected for this study were marble powder, talc and China clay. From this study, talc was found to impart good mechanical properties such as indentation hardness index, flexing properties, compression set at constant strain and stress and split tear strength. It was also found that the chemical properties such as ageing resistance and water absorption properties for talc-filled foam were found to be equivalent to NRL foam without filler. Amongst the fillers studied talc possesses better mechanical and chemical properties followed by marble powder and China clay. Scanning electron microscope (SEM) image analysis of NRL foam at 500 μm scale with talc is self-explanatory to the above-mentioned facts.