In this research work, the effects of natural fibers such as date palm fiber (DF) and jute fiber (JF) on bending properties of polypropylene (PP)/ ethylene–propylene–diene–monomer (EPDM) thermoplastic elastomers are investigated. For this purpose, the date palm and jute fibers at five levels of fiber weight fractions (0, 5, 10, 20 and 30 wt. %) are utilized during composite fabrication. Maleic anhydride grafted to polypropylene (MAPP) is used as coupling agent to increase the interfacial adhesion between the polymer and the fibers. Results show that by adding fiber to the matrix, the bending properties are increased, but elongation at break is decreased. پرونده مقاله

Changes in moisture content and temperature can perturb both stiffness and strength and as such the impact resistance of composite structures. In this paper, the pre-notched basalt fibre reinforced epoxy (BFRE) composite specimens are studied under Charpy impact loads in order to investigate the changes in impact energy absorption (fracture toughness) with different kinds of aging conditions. To create three types of aggressive environmental conditions, the specimens were frozen in dried air at T= -18 °C, frozen in tap water at T= -18 °C and kept in tap water at T= 30 °C and the results were compared with the specimen without aging influence (T= 25 °C). Water used for this examination has a high percentage of precipitation (70-80%) which causes high corrosion and consequent decrease in mechanical properties. The outcomes illustrated that the long-term exposure to tap water (T= 30 °C), dried air (T= -18 °C) and frozen in tap water (T= -18 °C) were all affected on energy absorption of BFRE composites, however, freezing effect in water was more intense. To study the nature of the failure mechanisms, all failed specimens were inspected by Scanning Electron Microscopy (SEM) photographs. پرونده مقاله