Hanafi Ismail

The Effect of Halloysite Nanotubes as a Novel Nanofiller on Curing Behaviour, Mechanical and Microstructural Properties of Ethylene Propylene Diene Monomer (EPDM) Nanocomposites

Halloysite nanotubes (HNTs) with hollow nanotubular structures were used as a new type of filler for ethylene propylene diene monomer (EPDM) matrix. EPDM/HNT nanocomposites were prepared using a two roll mill by adding 0 to 100 parts per hundred rubber (phr) HNTs. The results show that the tensile properties were increased with the addition of HNTs. The curing time decreased from 0 to 15 phr loading but subsequently increased from 15 to 100 phr, whereas the maximum torque exhibited an increasing trend from 0 to 100 phr. The addition of HNTs reduced the tan δmax and increased the storage modulus especially for the EPDM/HNT nanocomposites at high HNT loading.

Multiwall Carbon Nanotube-Filled Natural Rubber: The Effects of Filler Loading and Mixing Method

The NR/MWCNT nanocomposites were prepared by incorporation of MWCNT at different loading using two different methods, i.e., mechanical and solution mixing. For NR/MWCNT that prepared by mechanical mixing method, the results show that the scorch and cure time decrease with increasing MWCNT loading. The tensile modulus increase with increasing MWCNT loading but decrease the tensile strength, fatigue life and elongation at break. The SEM results show there is a lot of agglomeration of MWCNT occurred. Using the solution mixing method, the MWCNT are well dispersed in the natural rubber matrix and the tensile properties and fatigue life of NR/MWCNT were enhanced.

Effect of Partial Replacements of Sand and Cement by Waste Rubber on the Fracture Characteristics of Concrete

In this study, the influences of partial replacements of sand by fine crumb and crumb rubber particles, and cement by powder rubber, on the fracture characteristics of concrete were investigated experimentally. Specimens were prepared for 5%, 10% and 20% replacements by volume, for both sand and cement. Each case had three unnotched and notched specimens of size 600 mm × 75 mm × 150 mm; notches were 50 mm and 75 mm deep. The specimens were subjected to three points bending test in a computer-aided universal testing machine, and the fracture characteristics such as GIC, CMOD and Gf were analyzed. It was observed that, in all proportions, the replacement of sand by fine crumb and crumb rubber increased the fracture properties; the increase of fracture properties by crumb rubber was more than that by fine crumb rubber. However the cement replacement by powdered rubber could improve the fracture factors, only for 5% and 10% replacements.

Effect of Additives on Properties of Polyvinyl Alcohol (PVA)/Tapioca Starch Biodegradable Films

Effect of additives on properties of PVA/tapioca starch biodegradable films was studied. The additives used in this research were glycerol (GLY), polyethylene glycol (PEG) and glutaraldehyde (GLU). PVA/tapioca starch blend films were prepared by mixing process and casting method. Increased the GLY and PEG level, increased the elongation at break but decreased the tensile strength of PVA/tapioca starch blend film. The addition of plasticizer also increased the biodegradability, water absorption and water vapor transmission of PVA/tapioca starch blend film. However, GLU showed the opposite results.

Properties of polypropylene/natural rubber/recycle rubber powder blends

Thermoplastic elastomers have been prepared by blending polypropylene (PP), natural rubber (NR), and recycle rubber powder (RRP). The blends were melt-mixed using a Brabender Plasticorder torque rheometer at 190°C and 50 rpm. A fixed 70:30 blend ratio (wt%) of PP and rubber was prepared. The effect of partial replacement of NR with RRP at a fixed rubber content (NR+RRP), 30 wt% on mechanical properties, swelling behavior, torque development, and morphological properties of PP/NR/RRP blends was studied. Results show that the tensile strength, Youngs modulus, and swelling resistance increase with increasing RRP content in the PP/NR/RRP blends whereas the stabilization torque and elongation at break exhibit opposite trend.

THE COMPARISON PROPERTIES OF RECYCLE RUBBER POWDER, CARBON BLACK, AND CALCIUM CARBONATE FILLED NATURAL RUBBER COMPOUNDS

The effects of filler loading on the curing characteristics, swelling behavior, and mechanical properties of natural rubber compounds were studied using a conventional vulcanization system. Recycle rubber powder (RRP), carbon black (CB) (N550), and calcium carbonate (CaCO3) were used as fillers and the loading range was from 0 to 50 phr. Results show that the scorch time, t 2, and cure time, t 90, decrease with increase in filler loading. At a similar filler loading, RRP shows shortest t 2 and t 90 followed by CB and calcium carbonate. The tensile strength, tensile modulus, and hardness increase with increase in CB loading, whereas elongation at break, resilience, and swelling properties show opposite trend. For RRP and calcium carbonate filled natural rubber compounds, the tensile strength increases up to 10 phr and starts to deteriorate at higher filler loading. The other properties such as tensile modulus, hardness, elongation at break, resilience, and swelling percentage show a small change (increase or decrease) with increase in RRP and calcium carbonate loading in natural rubber compounds. Overall results indicate that RRP can be used as a cheapener to replace calcium carbonate in natural rubber compounds where improved mechanical properties are not critical.

Curing Characteristics, Mechanical, Thermal, and Morphological Properties of Halloysite Nanotubes (HNTs)-Filled Natural Rubber Nanocomposites

Halloysite nanotubes (HNTs)-filled natural rubber (NR) nanocomposites with various filler loading were prepared by using a two-roll mill. The addition of HNTs increased the scorch time, cure time and maximum torque but reduced curing rate index. The tensile strength increased up to 20 phr of HNTs and then decreased. When HNTs loading increased, the elongations of break, swelling percentage and fatigue life were decreased while modulus at 100% and 300% elongation and thermal properties showed inversely. The dispersion of HNTs inside the NR matrix is shown from SEM images.

Recycled Polyethylene Terephthalate Filled Natural Rubber Compounds: Effects of Filler Loading and Types of Matrix

Recycled polyethylene terephthalate (R-PET) was utilized as a filler in natural rubber (SMR L) and epoxidized natural rubber (ENR 50) compounds. Results indicated that the maximum torque, scorch, and cure time of SMR L compounds increased with increasing R-PET loading, whereas ENR 50 compounds showed the decreasing trend in scorch and cure time. Increment in R-PET increased crosslink density and tensile modulus of both natural rubber compounds. Tensile strength, elongation at break, and fatigue life of both natural rubber compounds showed the decreased trend with increasing R-PET loading but ENR 50 showed the lower values than SMR L compounds. The thermal degradation was shifted to a higher temperature and the micrographs exhibited the detachment of R-PET and more agglomeration with increasing R-PET loading in both natural rubber compounds.

Carbon Black (CB)/Rice Husk Powder (RHP) Hybrid Filler-Filled Natural Rubber Composites: Effect of CB/RHP Ratio on Property of the Composites

Carbon black (CB)/rice husk powder (RHP) hybrid filler filled natural rubber (NR) composites with various filler ratios (0/30, 5/25, 10/20, 20/10 and 30/0) were prepared. The influence of CB/RHP ratio on curing characteristics, tensile properties and fatique life of the composites was investigated. It has been found that incorporation of CB in the hybrid filler decreases the scorch time and cure time but increases maximum torque. As CB content increases, the tensile strength, modulus at 100% and 300% elongation and fatique life increase whereas the elongation at break decreases. SEM studies also reveal poor adhesion between RHP particles and NR matrix which causes inferior mechanical properties.

Impact Resistance of Concrete with Partial Replacements of Sand and Cement by Waste Rubber

Effects of partial replacements of sand by waste crumb rubber and fine rubber, and cement by powder rubber, on the performance of concrete under low velocity impact loading were investigated. Specimens were prepared for 5%, 10% and 20% replacements by volume for both sand and cement. For each case, six beams of 100 mm × 100 mm × 500 mm were subjected to 5.15 kg hammer from 900 mm height. The number of blows of the hammer required to induce the first visible crack and ultimate failure of the beam were recorded. The results are presented in terms of impact energy required for the first crack and ultimate failure. The crumb and fine crumb rubbers increased the impact energy for both first crack and ultimate failure; the increase of impact resistance by crumb rubber was more than that by fine crumb rubber. However, the impact energy for both first crack and ultimate failure increased by the replacement of sand with fine crumb and crumb rubbers until 20%, while this energy increased with cement replacement by powder rubber until 10% replacements and then decreased, but is still higher than that of plain concrete.