Mohamad Awang

Influence of Hydrophilic Polymer on Pure Water Permeation, Permeability Coefficient, and Porosity of Polysulfone Blend Membranes

It is well known that membrane with hydrophobic property is a fouling membrane. Polysulfone (PSf) membrane has hydrophobic characteristic was blended with a hydrophilic polymer, cellulose acetate phthalate (CAP) in order to increase hydrophilicity property of pure PSf membrane. In this study, membrane casting solutions containing 17 wt% of polymer was prepared via wet phase inversion process. The pure PSf membrane was coded as PC-0. PSf/CAP blend membranes with blend composition of 95/5, 90/10, 85/15 and 80/20 wt% of total polymer concentration in the membrane casting solutions were marked as PC-5, PC-10, PC-15 and PC-20 respectively. All of the membranes were characterized in terms of pure water flux and permeability coefficient in order to study their hydrophilicity properties. The investigated results shows that increased of CAP composition in PSf blend membranes has increased pure water flux, permeability coefficient and porosity of the blend membrane which in turn formed membrane with anti-fouling property.

Effect of Shear Rate on Characteristics, Performance and Morphology of Polysulfone Blend Membranes

Rheological factor such as shear rate during membrane fabrication process has an effect on properties, structures and performance of membranes. Flat sheet asymmetric PSf/CAP blend membranes were prepared using an automatic casting machine at different shear rates in the range of 42.0 to 201.0 s-1. Results showed that increasing the shear rate from 42.0 to105 s-1 has increased the molecular orientation and thickness which then reduces the water content, porosity and pure water flux of PSf/CAP blend membranes. However, further increasing the shear rate beyond 105 s-1has resulted in an increase in the water content of PSf/CAP blend membranes.

Properties of Alpinia galanga Agro-Waste-HDPE Composites with Addition of MA-g-PE and Eco Degradant

Preparation of Alpinia galanga agro waste-high density polyethylene (HDPE) composites involved the addition of eco degradant and polyethylene-g-maleic anhydride (PE-g-MA). The Alpinia galanga agro waste fibers at 3, 6, 10 and 15 wt% were compounded in an internal mixer with the addition of 5 wt% MA-g-PE and eco degradant. The composite specimens were prepared using an injection molding machine. The results show that the maximum tensile strength of 33 MPa was obtained for sodium hydroxide (NaOH) & 3-aminopropyltriethoxysilane (3-APE) treated fiber composites with eco degradant and MA-g-PE at 15 wt% fiber loading compared to that of pristine HDPE (28 MPa). All the treated composites show an improvement in tensile strength. This indicates that the treatments using NaOH&3-APE and p-toluenesulfonic acid (PTSA) with addition of eco degradant and PE-g-MA improved adhesion between Alpinia galanga fiber and HDPE matrix. The Scanning Electron Microscopy (SEM) micrographs show the presence of a improved interaction between treated Alpinia galanga fibers and HDPE matrix with the addition of eco degradant and MA-g-PE. Thermal stability of composites was also improved for composites with treated fibers.

Effect of Cellulose Acetate Phthalate (CAP) on Characteristics and Morphology of Polysulfone/Cellulose Acetate Phthalate (PSf/CAP) Blend Membranes

Polysulfone (PSf) membrane is catogorized as hydrophobic membrane that easily fouled during membrane operation process. The presence of second hydrophilic polymer which added into membrane casting solutions plays a crucial role in adjusting the membrane properties. This hydrophilic polymer was employed in hydrophobic polymer membranes in order to improve hydrophilicity and performance as well as formed antifouling ultrafiltration (UF) membranes. In this study, a hydrophilic polymer, cellulose acetate phthalate (CAP) was added into polysulfone (PSf) membrane casting solutions by blending technique to produce PSf/CAP blend membranes. Flat sheet asymmetric PSf/CAP blend membranes were prepared by wet phase inversion method. The results revealed that an increase in CAP increased the hydrophilicity properties of PSf/CAP blend membranes compared to pure PSf membrane. The significant changes in size and numbers of microvoids and macrovoids in the morphological structures of PSf/CAP blend membranes were due to CAP promote the instantaneous liquid-liquid demixing during phase inversion process.

Utilization of Agro-Waste A. galanga Natural Fibers in Composites

Utilization of locally abundant agro-waste Alpinia galanga (A. galanga) natural fibers in polyethylene (PE) was investigated. The results indicate that agro-waste fibers generally function as potential natural-organic fillers as well as show an attribute of reinforcement in PE-agro-waste composites at a certain fiber loading. Minimally reduced tensile strength from 28 MPa of unfilled PE, addition of agro-waste A. galanga natural fibers also resulted in reinforcement of up to 31 MPa at 6 wt% agro-waste fibers loading. Findings also reveal that alkali treatment was effective to impart surface modification of agro-waste A. galanga natural fibers and hence improved tensile strength, modulus of elasticity and thermal stability of PE-agro-waste composites.

Study on Renewable Resource-Based Composites from Agro Waste Alpinia galanga Natural Fibers

Recently there has been a surge of interest in using natural fibers from renewable resources as alternative to replace traditional synthetic fibers. This is due to the increased environmental and sustainability awareness. In this study, high density polyethylene (HDPE) was compounded with untreated and treated agro-waste natural fibers Alpinia galanga. Alkali treatment using sodium hydroxide was used to improve the interface adhesion between fibers and polyethylene matrix. Polyethylene-Alpinia galanga composites were prepared using an injection molding machine at various fiber contents of 3, 6, 10 and 15 wt% and characterized. Experimental studies have shown that in general fibers function as filler in polyethylene composites and exhibited tensile strength relatively close to the strength of the unfilled composites. The increasing of Alpinia galanga content decreased elongation at break and increased the Youngs modulus of Polyethylene-Alpinia galanga composites. It was also observed that treated fiber composites showed higher thermal stability than that of untreated fiber composites.