Medhat M. Hassan

Waste newsprint fibers for reinforcement of radiation-cured styrene butadiene rubber-based composites - Part I: Mechanical and physical properties

In this study, waste newsprint paper fiber was treated by polystyrene emulsion and included as a filler in styrene butadiene rubber. Then, the composites were subjected to electron beam irradiation at different irradiation doses, and follow-up was done on the effect of irradiation dose and fiber concentration on mechanical and physical properties of prepared composites. The results indicated that the mechanical properties like tensile strength, elongation at break, stiffness, and toughness were enhanced by the increase of radiation and fiber content. Also, the physical properties like soluble fraction, swelling ratio, and volume fraction of rubber in swollen gel were enhanced by the increase of radiation and fiber content. On the other hand, scanning electron microscope (SEM) results confirmed that adhesion was situated between fiber and rubber matrix.

Effect of gamma irradiation on some properties of reclaimed rubber/nitrile–butadiene rubber blend and its swelling in motor and brake oils

Reclaimed rubber powder (RRP) was treated by the addition of glycidyl methacrylate (GMA) to impart desired properties suitable for oil resistance applications. The produced GMA-RRP was mixed with nitrile–butadiene rubber (NBR) in various compositions. The blends were irradiated with gamma radiation doses of 50–250 kGy. The compounding of the blend factors has been elaborated using Fourier transform infra-red spectroscopy and scanning electron microscopy (SEM). Different properties of the synthesized unirradiated and irradiated blends such as tensile strength, elongation at break, hardness, swelling behavior in motor and brake oils and thermal stability were investigated with respect to the RRP content. Results show that the tensile strength, hardness and swelling resistance increase with increasing NBR content in the blend. It has been shown that the tensile strength increased with dose. Similarly, hardness values, reported for the same composition, apparently increased with dose within the range of 50–250 kGy. The residual mass percentage of blends obviously increased upon the incorporation of incremental RRP. The swelling percentage steadily decreases with increasing radiation dose due to the radiation-induced cross-linking.

Effect of gamma radiation on physico-mechanical properties of vulcanized natural rubber/carbon fiber composites:

Natural rubber was reinforced with a short carbon fibers (SCFs) at different concentrations (0–20 part per hundred part of rubber (phr)). The composites were vulcanized by sulfur, then subjected to gamma radiation at different doses up to 40 kGy. Physico-mechanical properties of composites were studied. Also, thermogravimetric analysis was used to investigate the influence of the incorporation of SCF on the thermal properties of prepared composites. It was observed that the mechanical properties like tensile strength increases with increasing irradiation dose up to 30 kGy and fiber loading up to 15 phr, meanwhile the hardness and modulus increase with increasing fiber loading, but not affected by irradiation dose. Thermal stability of composites was increased by fiber loading content at constant irradiation dose. The morphological studies were made by means of scanning electron microscopy to investigate the structure change caused by the incorporation of SCF.

Investigation of physico-mechanical properties of flexible poly (vinyl chloride) filled with antimony trioxide using ionizing radiation

ABSTRACT Composites of polyvinyl chloride (PVC) with 2% calcium carbonate, 2% diethyl phthalate, 2% paraffin wax and 2% lead sulphate and different contents of antimony trioxide (Sb2O3) prepared by melting and irradiated with gamma ray have been considered. Assessment of the mechanical and thermal properties of the unirradiated and irradiated flexible polyvinyl chloride (FPVC) were completed utilizing elasticity (TS), Elongation at break (Eb) and thermogravimetric analysis measurements. TS and thermal stability of FPVC displayed advanced improvement after addition of additives and this approach highlighted the efficiency of those ingredients on PVC. The compounding of FPVC with Sb2O3 in various extents was examined by FTIR, X-ray diffraction and scanning electron microscope methods. It is obvious that the presence of Sb2O3 begins impacting oxidative degradation, leading to a decrease in mechanical properties up to 10%. Moreover, a slight increase in the thermal stability of composites by exposure to ionizing radiation is apparently due to cross-linking of FPVC chains. GRAPHICAL ABSTRACT

Effect of carbon fiber and gamma irradiation on acrylonitrile butadiene styrene/high density polyethylene composites

In this study, the effect of carbon fiber and gamma irradiation on acrylonitrile butadiene styrene (ABS)/high density polyethylene matrix was investigated. The ternary composites with short carbon fiber of concentrations 15, 30, and 45 wt % were irradiated with doses of 100 and 300 kGy. In order to characterize the physical and morphological properties of all reinforced composites, wide X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, and scanning electron microscopy were performed.