Mechanical characterization of natural rubber composites added with a low volume of crab chitin whiskers

Chitin nanowhiskers have been introduced in limited amounts, up to 15 wt.%, in a natural rubber matrix, with the objective to evaluate if this procedure, without substantially modifying the non-polar properties of natural rubber for the small quantity of filler introduced, could be advantageous as for other aspects. With this aim, tensile and creep tests have been performed. The former demonstrated a steadily growing positive effect on tensile properties for all configurations starting at 5 wt.% chitin nanowhiskers, despite their difficulty to hinder deformation, whilst the latter showed some effect only for 10 and 15 wt.%. No perceivable effects have been noted on glass transition temperature at any amount of filler. However, some changes in surface morphology and fracture behaviour were observed by electron microscopy as an evidence of the effect of introducing chitin nanowhiskers in natural rubber.