Papers by Author: Hassan Norita

Abstract: This paper discusses the inclusion of hybrid nanofillers nanoclay and multi-walled carbon nanotubes (MWNTs) as reinforcing agents to improve the thermal properties of TPNR. The laser flash technique was also employed to determine the thermal conductivity, thermal diffusivity and specific heat capacity of the nanocomposite. Two types of hybrid nanofillers were introduced into TPNR, which are untreated hybrid composites (UTH) prepared from MWNTs (without acid treatment)-nanoclay and treated hybrid composites (TH), consisting of acid treated MWNTs and nanoclay. The thermal properties of treated hybrid composites are better than untreated hybrid composites. The thermal conductivity of untreated hybrid composites that were sintered at 30 to 150 oC did not show a monotonous change with MWNTs as the filler has a high thermal conductivity compared to nanoclay. The results showed that the thermal diffusivity decreased with the increasing of temperature. The specific heat of all the measured samples increases linearly with the measured temperature from 30°C to 150°C.

Abstract: Metal injection molding (MIM) is a near net-shape manufacturing technology that is capable of mass production of complex parts cost-effectively. The unique features of the process make it an attractive route for the fabrication of the new binder system since the success of MIM process is dependent on the outward appearance of the resultant feedstock. Thermoplastic natural rubbers (TPNR) blends consist of thermoplastics, such as polyethylene (PE), alloyed with natural rubber (NR) with different thermoplastic to NR ratios. The soft grade TPNR is produced by blends with compositions richer in rubber while the harder grades can contain up to about 30 % NR. This study investigates the influence of new binder system consisting of TPNR on injection parameter, density of injected molded specimen and changes during solvent extraction. Results show that TPNR plays an important role as a good binder system and shortens the solvent extraction process.

Abstract: Thermoplastic natural rubber (TPNR) nanocomposites were prepared by melt blending method with the optimum mixing parameters (140oC, 100 rpm, 12 min) using internal mixer (Haake 600 P). The aim of this work is to study the effects of organo-montmorillonite (OMMT) on the physical and mechanical properties of TPNR with and without coupling agent (maleic anhydride grafted polyethylene, MA-PE). Significant improvement in tensile strength and modulus of TPNR nanocomposites were obtained with the presence of MA-PE.

Abstract: Thermoplastic natural rubbers (TPNR) blends consist of thermoplastics, such as low density polyethylene (LDPE), alloyed with natural rubber (NR) with different thermoplastic to NR ratios. The soft grade TPNR is produced by blends with compositions richer in rubber while the harder grades can contain up to about 30% NR. This study investigate the influence of new binder system containning of TPNR on injection parameter, density of injected molded specimen and changes during solvent extraction. Results shows that TPNR plays an important role as a good binder system and shortens the solvent extraction process.