Mohamed Mansour Abdel Aziz

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

Ethylene propylene diene terpolymer ( EPDM) rubber nanocomposites have been prepared by incorporating 10 phr of organically modified montmorillonite (OMMT) nanoclay and various percentages of fumed silica (10, 20, and 30 phr) onto EPDM rubber composite using two roll mill and crosslinked by gamma radiation. The effect of radiation dose on the mechanical properties namely tensile strength and elongation at break and the physical properties namely solubility and swelling were investigated. Thermogravimetric analysis was carried out to analyses the thermal stability of the nanocomposites. Volume resistivity of the nanocomposites was also measured. The results showed that the mechanical, volume resistivity, and thermal properties of the irradiated EPDM rubber containing OMMT were increased by adding of the fumed silica. The effect of N,N‐m ‐phenylenedimaleimide coagent on the mentioned properties of the EPDM rubber nanocomposites was studied. The results showed that the physical, mechanical, and thermal properties of the irradiated EPDM rubber nanocomposites improved with the addition of the coagent due to the increase of the crosslinking density. The inclusion of both the 30 phr fumed silica and the coagent in the nanocomposite irradiated to 50 kGy leads to a synergistic effect. J. VINYL ADDIT. TECHNOL., 23:E188–E200, 2017. © 2016 Society of Plastics Engineers

The modified CeO ₂ was prepared by a chemical surface modification method. The action of CeO ₂ powders in EPDM composites contain 10 phr modified clay was studied. The effects of content and surface modification of CeO ₂ powders on the properties of the EPDM composites containing 10 phr modified clay rubber was discussed. The results showed that the mechanical, volume resistivity and thermal properties of EPDM rubber filled with the modified CeO ₂ increased by loading of modified CeO ₂ . And the tensile strength of EPDM composites containing modified CeO ₂ is higher than that with the unmodified CeO ₂ . The surface of modified CeO ₂ powders had a hydrophobic organized layer which could increase interface cohesion with the rubber and dispersity in rubber resulting in exerting reinforcement effect. The effect of coagent on the physical and thermal properties of EPDM rubber composites was studied. The results showed that the physical and thermal properties of EPDM rubber composites increased with the addition of the coagent due to the increase of the crosslinking density. J. VINYL ADDIT. TECHNOL., 23:E201–E210, 2017. © 2016 Society of Plastics Engineers