The effect of chitosan on the physico-mechanical and antimicrobial properties of gamma irradiated ethylene propylene diene monomer/fumed silica nanocomposites

Document Type : Original Article


1 Radiation Chemistry Department, National Center for Radiation Research and Technology, Egyptian Atomic Energy Authority, Cairo, Egypt, B.O. Box 29 Nasr City, Cairo, Egypt


3 Egyptian Petroleum Research Institute, Petrochemical department, polymer lab.


The goal of this research is to evaluate the recovered chitosan from locally discarded shrimp shells for usage as a biofiller for ethylene propylene diene monomer (EPDM) rubber in green chemistry industries. The utilization of two distinct fillers are expected to improve the qualities of industrial applications while lowering the cost. A laboratory two-roll mill, was used to prepare the rubber nanocomposites by incorporating nano fumed silica and chitosan as biomaterials into the EPDM rubber matrix. The mechanical and morphology characteristics of the produced EPDM rubber were investigated. The rubber nanocomposites were exposed to gamma irradiation doses ranging from 20 to 150 kGy. The tensile strength (TS) of the EPDM/chitosan/fumed silica vulcanizate increased when the chitosan concentration was raised up to 5 phr, but the elongation at break was reduced. However, the use of fumed silica as binary filler with chitosan improved the mechanical performance and thermal stability. The influence of gamma irradiation on the mechanical properties was also explored. The antimicrobial activity of the EPDM nanocomposites agaist Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria was investigated in terms of the zone of inhibition. The results indicated that the nanocomposites irradiated to 100 kGy and containing 10 phr fumed silica and 5 phr chitosan exhibited the highest mechanical, thermal, and antibacterial characteristics and might be used in a variety of applications such as packaging material and surface application/coating based for different devices


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