A comprehensive review on cellulose, chitin, and starch as fillers in natural rubber biocomposites

Biofillers based on cellulose, chitin, starch, and their composites have been topics of interest during the last few decades because of their eco-friendliness, low-cost, and good thermomechanical properties. The biofillers based on plant fibers are hydrophilic that reduce the compatibility with rubber matrix. In this manuscript, an effort has been made to review cellulose, chitin, and starch, focusing on their preparation and properties of natural rubber (NR) based composites reinforced with these fillers. The main characterization properties of NR based composites, such as mechanical, thermal, and biodegradability were discussed. The filler-NR interactions were also explored. The small size of the filler improved the physical interaction between the filler and matrix, and consequently, mechanical, thermal, sorption, crystallinity, and biodegradability of the biofillers/NR composites were found to be improved. Finally, the applications of NR-based composites reinforced with cellulose, chitin, and starch were reviewed in different areas such as medical, food packaging, footwear, sensors and water purification to study their practical uses.