Noraiham Mohamad

Correlation of filler loading and silane coupling agent on the physical characteristics of epoxidized natural rubber-alumina nanoparticles composites

Studies were conducted on the effects of filler loading and 3-aminopropyltriethoxysilane (SCA) on the physical characteristics of epoxidized natural rubber (ENR)-alumina nanoparticles composites (ENRAN). The filler loading varied from 10, 20, 30, 40, 50, and 60 phr in the absence and presence of 2 phr SCA in every formulation. The alumina nanoparticles have a positive interaction with the ENR matrix since they increase the glass transition temperature of the composites [Mohamad, N., Muchtar, A., Ghazali, M.J., Dahlan, H.M. and Azhari, C.H. (2008). The Effect of Filler on Epoxidized Natural Rubber-Alumina Nanoparticles Composites, Eur. J. Sci. Res., 24: 538—547]. The addition of SCA decreased the maximum torque (MH) and the torque difference (MH-ML) of ENRANs compound as well as causing the curing process to occur at a very fast rate. The spherical alumina particles were dispersed in ENR matrix and a uniform particle distribution was observed under scanning electron microscope enabling the increase of the torque values in the composites.

Boric acid modified starch polyvinyl alcohol matrix for slow release fertilizer

Abstract The slow release urea fertilizer was prepared by the boric acid crosslinked starch/polyvinyl alcohol (SPB) matrix as biodegradable carrier material. Using a two level factorial design of experiment, a comprehensive understanding of the concentration of boric acid, reaction time and heating temperature in the preparation of SPB matrix was obtained. The swelling ratio, release profile of urea in water, and crushing strength were selected as the response. The interaction between the variables and response was analyzed using the ANOVA model. The system was confirmed using the constant determination, R2 with values above 0.99. The high concentration of boric acid with a prolonged reaction time at high temperature gave relative good results of swelling ratio, dissolution rate of urea and crushing strength. In the 28-day soil incubation experiment, the retention of exchangeable ammonium ion (NH4+)

A Sustainable Polymer Composite from Recycled Polypropylene Filled with Shrimp Shell Waste

{\rm{(NH}}_4^ + )

Processability of polypropylene/multiwalled carbon nanotube nanocomposites via direct melt compounding

was significant higher in SPB urea as compared to pure urea. There was a potential for SPB matrix to improve nitrogen efficiency by increasing the accumulation of exchangeable NH4+

NR/EPDM elastomeric rubber blend miscibility evaluation by two-level fractional factorial design of experiment

{\rm{NH}}_4^ +

Application of response surface methodology for optimizing the oxidative stability of natural ester oil using mixed antioxidants

and decreasing the dissolution rate of urea in the flooded condition.

Non-Covalent Polymeric Wrapping of IGEPAL C0890 for Graphene Nanoplatelets (GNPs-C0890) Filled NR/EPDM Rubber Blend Nanocomposites

This research explores the potential of using recycled polypropylene (PP) incorporated with shrimp shell waste to produce a sustainable polymer composite. In this study, the mechanical and physical properties of recycled polypropylene/shrimp shell (rPP/SS) composites prepared by melt compounding and compression molding techniques were evaluated. The effects of SS loading were investigated by using various compositions of rPP/SS composites, ranging from 0 to 8 wt.% SS that consists of two different sizes, i.e., fine and coarse SS. The composites were tested for their mechanical and physical properties using impact, tensile and water absorption tests. Furthermore, the morphology of the composites was examined by using a scanning electron microscope (SEM). Incorporation of SS was found to increase the Youngs modulus of the rPP, but the impact and tensile strength showed a decrease. However, we observed that both the impact and tensile strength improve with the further increase of the SS content. In other words, composites with high shrimp shell loading were observed to exhibit better tensile and impact properties compared to composites with low shrimp shell loading. Moreover, at 8 wt.% of SS, the value of tensile strength is comparable to that of neat rPP.

Electrically Conductive Aluminum Oxide Thin Film Used As Cobalt Catalyst-Support Layer In Vertically Aligned Carbon Nanotube Growth

This article presents the effect of filler loading on compounding torques as well as mechanical properties of polypropylene/multiwalled carbon nanotube (PP/MWCNTs) nanocomposites. Samples were prepared via melt compounding method using a Haake internal mixer at rotor speed of 80 r/min. The torque values in a 10-min compounding period for the incorporation of MWCNTs fillers into PP matrix were analyzed and thoroughly evaluated. The data was further confirmed by morphological analysis via transmission electron microscopy. The efficiency of direct melt-compounding method using internal mixer was evident from the homogeneity of MWCNTs dispersed within the PP matrix observed in produced nanocomposites at filler loading up to 0.75 wt%. MWCNTs showed significant compatibility with PP matrix and proved the needlessness of chemical pretreatment and complicated compounding process to produce PP/MWCNTs nanocomposites. The mechanical properties and morphological characteristics were in good correlation with the processing behavior of the nanocomposites.

Wear Behaviour of Cryogenic Treated Recycled Carbon Fibers Filled Epoxy Composite

Fractional 25 two-level factorial design of experiment (DOE) was applied to systematically prepare the NR/EPDM blend using Haake internal mixer set-up. The process model of rubber blend preparation that correlates the relationships between the mixer process input parameters and the output response of blend compatibility was developed. Model analysis of variance (ANOVA) and model fitting through curve evaluation finalized the R2 of 99.60% with proposed parametric combination of A = 30/70 NR/EPDM blend ratio; B = 70°C mixing temperature; C = 70 rpm of rotor speed; D = 5 minutes of mixing period and E = 1.30 phr EPDM-g-MAH compatibilizer addition, with overall 0.966 desirability. Model validation with small deviation at +2.09% confirmed the repeatability of the mixing strategy with valid maximum tensile strength output representing the blend miscibility. Theoretical calculation of NR/EPDM blend compatibility is also included and compared. In short, this study provides a brief insight on the utilization of DOE for experimental simplification and parameter inter-correlation studies, especially when dealing with multiple variables during elastomeric rubber blend preparation.

Mechanical Properties of Short Fiber and Non-Woven Kenaf Reinforced Polypropylene Composites: Effects of Oil Palm Shell Powder Addition

Natural ester insulation (NEI) oils have been developed since the early 1990s due to the increasing environmental, health and safety concerns from the public. NEI oils are well-known for having high fire and flash points, great moisture tolerance, good biodegradability and non-toxicity. However, NEI oils also have several drawbacks compared to mineral insulation (MI) oils such as low oxidative stability, high viscosity, low pour point and low resistance towards lightning impulse. Previous researchers have discovered that the oxidative stability of NEI oils can be improved by the addition of mixed antioxidants. However, such studies are focused on only one criterion and they neglect the dielectric strength of the oils. On the other hand, the one-factor-at-a-time (OFAT) method is commonly used to determine the optimum concentration of mixed antioxidants and requires a large number of samples. In this study, response surface methodology (RSM) technique is used to determine the optimum concentration of mixed antioxidants which will enhance the oxidative stability of NEI oil. The dielectric strength of the NEI oil is evaluated based on the AC breakdown voltage (BdV). RSM is chosen in this study because it is capable of determining the optimum values of the parameters of interest, without the need for a large number of test runs which will incur high cost for experimentation. A regression model is developed in this study based on the AC breakdown voltage of the NEI oil, propyl gallate and citric acid antioxidant concentrations. The oxidative induction time (OIT) and partial discharge inception voltage (PDIV) are carried out to determine the effect of the oxidative stability and withstand voltage on the partial discharge, respectively. The results showed that there is enhancement in the oxidative stability and dielectric strength of NEI oil using the optimum concentrations of mixed antioxidants relative to the fresh NEI oil. It can be concluded that RSM is a feasible alternative to determine the optimum concentration of antioxidants for NEI oils, which in turn, helps improve the oxidative stability and dielectric strength of these oils.