Investigation of dynamic characteristics of nano-size calcium carbonate added in natural rubber vulcanizate

The nano-calcium carbonates (NCC) with spherical and chain polymorphs and 30 nm, 50 nm, and 80 nm sizes of cube shape particle have been used to prepare nano-calcium carbonate (nano-CaCO3)/natural rubber (NR) nano-composite. The influence of NCC on the properties of rubber vulcanizates such as Mullins effect, Payne-effect, loss factor and the dynamic compressed heat generation on the structure of nano-composite were investigated. The results showed that the Mullins effect of rubber composite filled chain shape NCC was high and it was comparable to the large particle size (80 nm) of cubic NCC. For the analysis of Payne effect, the value of ΔG′ of rubber composite filled with spherical shape has the lowest value due to weaker filler network resulted largest inter-aggregate distance occurred in the rubber matrix. Meanwhile, the chain and large particle size cubic NCC have more significant ΔG′ with the increasing of strain. The value of damping factor corresponds to energy loss showed that large particle size NCC has more pronounced values. Both chain and 80 nm cubic NCC have highest rising of temperature compared to spherical NCC added rubber composites.