Materials Science Forum Vol. 1115

Abstract: Composite material has been widely used in various industries because of its superior properties. But when used in harsh environment the composite material is susceptible to aging under the influence of UV radiation, water, temperature, humidity and other natural environmental medium. To evaluate the environmental adaptability of composite material, exposed 3238A/CCF300 in marine atmospheric environment for 3 year. The results show that the morphology exhibit brightness enhancement and surface resin decomposition. And the mechanical properties including 90° tensile strength, 0° compressive strength, bending strength, shear strength have all decline, amongst which the 90° tensile strength declines 55.4%, is most sensitive to marine atmospheric environment. Finally analyses the failure mechanism of 3238A/CCF300 due to the combination of heat-humidity aging and photo-degradation process.

Abstract: In order to analyze the stress concentration impact, intensity close to the zone of the crack tip, this work examines the in-plane SIF(SIF) of composite plates utilizing measured crack tip opening displacement (CTOD). The test specimens' E-glass fiber mats were arranged in various ply configurations. The ASTM standards utilized for researching mode I fracture of composite materials served as the foundation for the compact tension (CT) specimen. The mode I, K_I Stress intensity factor (SIF), and critical stress, c, were calculated for each specimen along the fracture length propagation based on the experiments. It was found that the SIF is directly proportional with fracture length, or a/W, for all E-glass fiber laminate cases tested. The K_IC is often higher in thinner laminates. The presence of woven roving increases the SIF and hence the toughness of the laminate.

Abstract: Post buckling analysis of E-glass fiber reinforced cylindrical composite under axial compression using both experimental and numerical method is presented. Using the Eigen value buckling analysis, the studies employ a mixture ratio of E-glass fiber composite of chopped strand mat. Five molds of each E-glass fiber mixture were reinforced with polyester resin to produce cylindrical shells of equal dimensions. Various cylindrical specimens’ predicted critical buckling load were tested and recorded using a compressive loading machine. Comparisons were made to ascertain the cylindrical shells buckling and post buckling behavior at certain load levels between the experimental and analytical results. A one-way Anova was used to compare the outcome of the theoretical, experimental and numerical methods of analysis and the result showed that there is no evidence to suggest difference between the three methods applied in the buckling load analysis. The post buckled shapes of the samples were obtained and recorded as bulge diamond shape of a buckled cylindrical structure. The effective mechanical properties of the chopped strand mat (CSM) reinforced composite cylinder were recorded from the experiment which has modulus of Elasticity 197.707 N/mm², Poisson’s ratio of 0.22 and density of 1250 Kg/m³.

Abstract: This paper evaluated the swelling of graphite resin electrodes developed for utilization in the electrochemical treatment of gold mining wastewater. Graphite-resin electrodes were developed from used dry cells and resin using non-heat treatment processes (segregation). The Microstructure of the electrode was determined using a scanning electron microscope (Carl Zeiss Smart Evo 10) to ascertain the composition of the electrode. The swelling property of the electrodes was measured using the standard method through a combination of gold mining wastewater and chloride salt solutions. Effects of operational factors (particle size, percentage binder and compressive “compacting” pressure) on the swelling of the electrodes were monitored and evaluated statistically (using analysis of variance). Weibull probability distribution (2 and 3 parameters) was applied to the swelling through Microsoft Excel Solver and Moment Likelihood Method to ascertain the usefulness of the electrode in environmental pollution control through computation of reliability. The study revealed that the swelling was in the range of 1.48 % to 2.24 %, particle size (F_5,20 =196.48, p = 2.76 x 10^-16), percentage binder (F_4,12 =181.58, p = 1.27 x 10^-10), and compressive pressure (F_3,12 = 106.69, p = 6.43 x 10^-9) were significant factors that influence swelling of graphite-resin electrode at 95 % confidence level. the values of α and β for 2-parameters Weibull distribution are 63.162 and 15.098, and 1.265 and 10.089 for MSE and MLM methods, respectively. The Table shows that the values of α, β and θ for 3-parameters Weibull distribution are 3.679, 8.097 and 0.168, and 4.350, 7.165 and 0.198 for MSE and MLM methods, respectively. It was concluded that particle size and compacting pressure are significant factors that had an effect on the swelling of graphite resin electrodes for treatment water and wastewater.

Abstract: The objective of this article was to study the corrugated bagasse fiber composite roofing properties of adhesive substances that are widely used in any industry. PF and pMDI were used as adhesives in this study at equal concentrations to determine the physical properties, and mechanical properties of corrugated roof tiles made from bagasse fiber composite materials, which were achieved from the waste of the sugar industry in Thailand to create a value-added. The corrugated dimensions of 400 mm in width, 400 mm in length, and 6 mm in thickness were manufactured and followed the standard densities of 400, 600, and 800 kg/m³. The results of the physical, and mechanical properties test reveal both PF and pMDI acquired optimal 800 kg/m³ densities with excellent moisture content. The modulus of elasticity and rupture, including impact strength, are also very impressive at high densities.

Abstract: Kenaf fiber possesses the capability for application in bio-composite materials, owing to its appealing mechanical and physical properties. This research aimed to achieve the optimum flexural strength of kenaf fiber/epoxy bio-composites materials with variations in kenaf fiber content, curing time, and curing temperature using a casting process. This study found that kenaf fiber addition increased the flexural strength of kenaf fiber/epoxy bio-composite, by varying curing time (30, 45, and 60 minutes) and curing temperature (60, 90, and 150 °C). The results showed that the highest flexural strength was obtained at 90°C (72.5 MPa) at 20/80 kenaf fiber content, at various curing temperatures. Meanwhile, the same highest flexural strength value (72.5 MPa) was also obtained for 20/80 kenaf fiber content, 45 minutes at various curing times. SEM image shows that 20 Wt.% kenaf fiber content has a better dispersion compared with 10 Wt.% so that affects the flexural strength value.

Abstract: Mechanical characteristics, dimensional stability, and bonding strength are all impacted by water sorption in polymer filler materials. The diffusion coefficient (D) of water through polymer composite, should be determined to understand the impact of the deterioration on service life and micro-leakage. In this study, the kinetics and properties of water absorption by short-term immersion in room-temperature plantain fibre reinforced epoxy bio-composites (PFRC), were studied. 5, 10, 20, and 30 percent, plantain fiber (PF) volume fractions of bio-composite specimens were made. Due to the high cellulose content of natural fibers (NF), the percentage of moisture absorption grew as the PF volume fraction increased. The mechanism and kinetics of PFRC's water absorption were found to follow the Fickian diffusion mode and had the propensity to behave in the Fickian mode.

Abstract: In this research, natural fibers (NF) were obtained from plantain pseudo stem. The extracted plantain fibers (PF) were modified by mercerization under diverse conditions in terms of treatment time and concentration. The crystallographic structures and macromolecular properties, and surface extracted PF were all influenced by the modification process. Improvements in thermal properties were observed along with increases in the crystallite size, and degree of crystallinity as revealed by x-ray diffraction (XRD) analysis. FTIR spectroscopy confirmed partial removal of wax, lignin, and hemicellulose. Bulk density was also observed to change under treatment conditions, while Scanning electron microscope (SEM) imagery demonstrates how the treatment altered the surface of the PF. A considerable change in the macromolecular and structural characteristics of plantain fiber was observed under optimum treatment conditions.

Abstract: Cellulose nanosphere (CNS) is a novel material isolated through delignification, bleaching, acid hydrolysis, dialysis, and sonication of cellulose fibers from agricultural wastes such as corn husk and rice straw. Comparative examination through multiple characterizations of CNS from these cellulose sources was conducted to investigate its potential applications. Corn husk cellulose nanospheres (CHCNS) and rice straw cellulose nanospheres (RSCNS) were characterized by its chemical characteristics, crystallinity, surface morphology and thermal stability. FTIR showed the same transmittance patterns for both CNS samples. The peaks for CHCNS and RSCNS in the NMR analysis were comparable, and the presence of toluene enabled the CNS dissolve better in DMSO-d₆. Higher crystallinity index was calculated in CHCNS than in RSCNS according to XRD analysis. TEM analysis demonstrated that CHCNS has shorter diameter than RSCNS. Lower onset degradation temperature relative to their corresponding bleached cellulose fiber was determined through TG Analysis. Biomedical applications such as drug delivery, wound dressings and tissue engineering are the most suitable applications based on the profiles of both CNS samples.