A. Rashid Azura

Effect of Fly Ash/Alkaline Activator Ratio and Sodium Silicate/NaOH Ratio on Fly Ash Geopolymer Coating Strength

Fly ash geopolymer coating material potential used to protect surface used in exposure conditions. Ratio of fly ash/alkaline activator and Na2SiO3/NaOH play important parameter on determining the best flexural strength of geopolymer coating material. Fly ash and alkali activator (Al2O3/Na2SiO3) were mixed with the solids-to-liquid ratios in range of 1.0-3.0 and different ratios of Na2SiO3/NaOH (1.0-3.0) to prepare geopolymer coating material at constant NaOH concentration of 10 M. Effect of fly ash/alkaline activator ratio and Na2SiO3/NaOH on geopolymer coating was determined with respect to the highest flexural strength of the 1200oC sintering temperature of geopolymer coating substrates. The results concluded that the highest strength for fly ash geopolymer coating material is achieved 42 MPa when the solid/liquid ratio is 2.0 and the Na2SiO3/NaOH ratio is 2.5.

Overview on the potential of Biodegradable Natural Rubber Latex Gloves for commercialization

Rubber gloves are one of the highest production of consumable and disposable commodity worldwide. These scenario in a way increased the volume of rubber solid waste disposal each year as the latex products commodity is design as a single used product. This is due to complexity of rubber/latex based products to degrade in nature environment hence increased the time for degradation in the landfill which normally occurred after more than 2 years. Thus, combination of rubber system with bio-materials is a feasible option. Novel Green Additives: Bio-Add is addded in NRL gloves formulation to accelerate biodegradation process. The biodegradable gloves were then being decomposed in soil for four (4) weeks and the mechanical properties were assessed. The result shows that, the mechanical properties of biodegradable gloves decreased as biodegradation week elapses. The addition of Novel Green Additives: Bio-Add have increased the biodegradability of NRL gloves. Novel Green Additives: Bio-Add offer an advantages to the latex based manufactured as it proven to accelerate the biodegradation process of the latex films using existing production line with minimal additional cost.

Synthesis of Porous Silica via Styrene Natural Rubber Sacrificial Template

Synthesis of porous silica via styrene natural rubber sacrificial template is investigated. This research is divided into three steps which are synthesis of Styrene Natural Rubber (SNR), SNR/silica film formation and formation of porous silica. The synthesis of SNR is obtained via emulsion polymerization which involves styrene as monomer and Deproteinized Natural Rubber (DPNR) latex as based materials. SNR is used as sacrificial template to produce porous silica. The amount of silica loading and mixing method were varied during formation of SNR/silica film. Calcination is use to completely remove styrene and latex, leaving behind a new material with porous structure. It was found that the increasing of silica loading will enhanced the porosity of the structure and the best mixing method can be obtained using shaker instead of mechanical stirrer and magnetic stirrer. The porous structure can be observed via Scanning Electron Microscopy (SEM).

Preparations and Characterization of Sago Starch Dispersion and Modification

Sago starch was mechanically treated with a stirring ball mill using anchoid as dispersing agent. Sago starch chemical modification was obtained from grafting copolymerization with polybutylacrylate (PBA) to reduce hydrophilic properties. The mechanical dispersed and chemical modified sago starches were studied through scanning electron microscopy (SEM), fourier transform infrared spectrometry (FTIR), and x-ray diffraction (XRD) analysis.

Effect of nanosilica fillers on the cure characteristics and mechanical properties of natural rubber composites

In recent years, polymer/nanofiller composites have received intense attention and become a core focus of nanoscience and nanotechnology. In polymer-nanoscale filler composites research, the primary goal is to enhance the strength and toughness of polymeric components using molecular or nanoscale reinforcement. In this study, nanosilica was used as filler with various loading from 1-5 phr to enhance mechanical properties and cure characteristics of natural rubber composites. 3 phr of nanosilica filler loadings showed highest tensile strength and shortest cure time compared to the other filler loadings. Tear strength was improved with increasing filler loadings. The effect of nanosilica loading has been analyzed using FTIR characterization and the tensile fracture was investigated by SEM analysis.

Bacillus megaterium sp. as Degradation Agent for Biodegradable Natural Rubber Latex Films

Degradation for biodegradable natural rubber (NRL) films by Bacillus megaterium sp. is investigated. A common soil bacterium, Bacillus megaterium sp. is one of the largest eubacteria. This bacterium has large potential in degradation process for biodegradable natural rubber latex film. Specified method is used to cultivate the bacteria using suitable media. The growth of bacteria is studied through optical density and dry weight as a function of time. The optical density at specific wavelength with different stages of bacterial growth is used to determine their mid-log growth phase of the cell. The optimum time achieved to insert NRL films is between 17 to 20 hours of incubation period. Growth curve of Bacillus megaterium sp. gives an equation of Y=2.3401X. The biodegradation behaviour of Bacillus megaterium sp. is further investigated to access the viability as accelerating media for biodegradation of NRL films.

Utilization of Metroxylan sagu Pith Waste as Biodegradable Filler for Natural Rubber (NR) Latex Films

Utilization of agricultural waste toward sustainability has increase a value-added product from a natural resources nowadays. Metroxylan sagu pith waste (MSPW) is a residue from starch extraction process. This research aim to investigate the potential of MSPW as a biodegradable fillers to replace sago starch in Natural Rubber (NR) latex films. The MSPW flour is characterized and compared with sago starch. Results shown MSPW has almost similar properties with sago starch with high content of starch (60%) and moisture (80%). Spectra of MSPW and Sago Starch (SS) are very closed to one another due to the similarity of functional groups. SS has granular shape while MSPW has irregular shape under SEM analysis. The addition of MSPW shown slightly lower tensile properties and tear strength as compared to SS but still within the acceptable value. Thus, MSPW has high potiential to replace SS as biodegradable fillers in NR latex films.

The Effect of Addition of Polysaccharide Materials on the Morphology of Freeze Fracture Surface of Natural Rubber Latex Films

Sago starch, amylose and amylopectin were used as fillers in natural rubber (NR) latex compounds. The compound was prevulcanized at 80 °C until chloroform number 2-3 was achieved. The effect of the fillers on the NR latex film mechanical properties (tensile properties and tear strength), and crosslink density were obtained. The fractured surface of the films was captured via scanning electron microscope (SEM) Zeiss Supra 35 VP. The results shown the addition of fillers reduced the tensile strength and elongation at break of the NR latex films but increased in the films tear strength. The swelling index of the films increased, indicating lower crosslink density possessed by the polysaccharide filled films. From the SEM micrograph, the addition of sago starch and amylose produced an uneven freeze fractured surface similar to the control starch films. Meanwhile, for films reinforced with amylopectin, the smooth surface is obtained indicating poor interfacial adhesion between filler and NR latex matrix.

The Effect of Wollastonite on Curing Characteristics, Tensile and Morphology of Natural Rubber Compounds

Wollastonite filled natural rubber (NR) compounds were prepared using a laboratory two-roll mill. The filler was loaded into NR at different loading, i.e., 0, 10, 20, 30 and 40 part per hundred of rubber (phr). The effect of wollastonite on curing characteristic, tensile and morphology properties has been studied. Results indicated that the cure time (t90), scorch time (t2), tensile strength and elongation at break of the NR compounds decrease with increasing wollastonite loading but the maximum torque, tensile modulus M100 (stress at 100% elongation), M300 (stress at 100% elongation) increase with increasing wollastonite loading. The fracture surface morphology of the NR compounds was investigated with a scanning electron microscope (SEM). More filler detachment from NR surface was observed with increasing wollastonite loading.

Synthesis of Porous Silica via Styrene Natural Rubber Template: The Effect of Calcination

This paper discussed the preparation of porous silica using styrene natural rubber (SNR) sacrificial template. The preparation of porous silica based on SNR template involved three steps which were the synthesis of SNR, the formation of SNR/silica, and the formation of porous silica. The SNR sacrificial template was synthesized using styrene as monomer and deproteinized natural rubber (DPNR) latex as based material. The effects of different silica loading and mixing methods were studied to produce SNR/silica films. Calcinations process was carried out to remove SNR to produce porous silica structure. The increasing of silica loadings enhanced the porosity of the template structure. The shaker mixing method produced better porous structure compared to the mechanical stirring and the magnetic stirring methods. The porous structure was analyzed via SEM which the optimum silica loading was obtained at 15 % of silica loading.