Evaluation of microstructure of natural rubber/nano-calcium carbonate nanocomposites by solvent transport properties

Abstract

The research on rubber reinforcement is a traditional but vitally essential topic. However, many issues in this aspect are presently still not well understood and explained. Moreover, when rubber reinforcement is obtained by using nanoparticles, it is even more difficult to clearly understand the relationship between the microstructure and properties. The special character of rubber, being a multicomponent system (rubber, vulcanising agent, accelerants, reinforcements, etc.), complicates even more the analysis of the parameters affecting the rubber/nanoparticle composite formation. Therefore, we believe the results obtained by means of transport experiments represent a good approach for understanding the reinforcing capability of nanofillers. The reinforcing capability of nano-CaCO 3 in natural rubber (NR) was characterised by means of transport properties such as diffusion, sorption and permeability coefficients, swelling ratio, enthalpy, entropy and activation energy. Concentration of nano-CaCo 3 in NR was varied from 0 to 20 parts per one hundred parts of rubber by weight (phr). Transport process of toluene by use of equilibrium weight swelling of the NR and nanofilled composites have been studied in details. The effects of nanofiller concentration and temperature on transport of toluene through nano-CaCO 3 filled NR vulcanisates were studied. The microstructure of the nanocomposites was investigated by scanning electron microscopy. The diffusivity data of the systems have shown the dependence on the temperature and microstructure of nanocomposite. Generally, the concentration of nano-CaCO 3 plays an important role in transport process.

Enhanced understanding of organic solvent transportation in NR-NBR blend reinforced with ferrite nanoparticles: A Comprehensive Investigation

“…As the curve does not adequately match the data, it is evident that the amount of solvent diffusing is not proportional to the amount remaining in the polymer matrix [47]. [46,48]. In the Fickian mechanism, diffusion is substantially slower than polymer relaxation.…”

“…It helps explain how the release rate fluctuates over time, especially when diffusion through the polymer matrix is the major mechanism. The equation discusses release/diffusion under Fickian or non-Fickian mechanisms[46,48]. In the Fickian mechanism, diffusion is substantially slower than polymer relaxation.…”