Surface modified palygorskite nanofibers and their applications as reinforcement phase in cis-polybutadiene rubber nanocomposites

In this paper, palygorskite nanofibers modified by liquid rubbers and mercapto silane coupling agent were used as reinforcement phase in the preparation of cis-polybutadiene rubber nanocomposites. The morphologies, structures, and performances, of the nanocomposite rubbers and modified palygorskite nanofibers were characterized. Results show that the liquid rubber coated palygorskite (PALHT) nanofibers reinforced cis-polybutadiene rubber nanocomposites exhibit superior performance, which indicates that liquid rubber coating is essential for optimizing the performance of the modified palygorskite nanofibers. This is attributed to penetration of organic molecules into the interlayer of palygorskite, resulting in formation of a three-dimensional network structure during the vulcanization. It is confirmed by the evidences that the characteristic diffraction peaks of palygorskite become weak and broadened distinctly, with a wide amorphous characteristic curve emerging around 15°-30°. The crosslinking force is much larger than that of the binding energy among the palygorskite crystal layers, which promotes peeling on the crystal face. This work demonstrates a feasible way to obtain an island-structured reinforced composite consisting of 3D network structure units.