Abstract: During sweating, textile materials would absorption water and then spread. The liquid spreading speed in the textile material would affect the comfort property. In this study, the liquid spreading speed of fabric-foam-fabric plied materials were studied. The plied material is intended to be used in close-to-skin garment such as intimate apparel. Thus, the liquid spreading speed of the material would affect its comfort property. The fabric-foam-fabric plied materials were prepared by plying polyurethane foams (non-laminated and laminated) with different fabrics. Therefore, we reported the liquid spreading speed values of different plied samples and the results were discussed properly.
Abstract: Pineapple leaves was utilized for the fabrication of cellulose acetate. It underwent a series of process that includes alkaline treatment using sodium hydroxide aqueous solution, bleaching treatment using acetate buffer and aqueous sodium chlorite, and acetylation using acetic anhydride. The preparation of cellulose acetate was done in different acetylation times (8, 16, 24 and 32 hours). The cellulose acetate samples were then characterized using fourier transform infrared spectroscopy (FTIR) to elucidate the vibrational move, thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) to investigate the thermal property of the material and scanning electron microscopy (SEM) to examine the surface morphology. FTIR result showed significant decrease in absorption intensity of the O-H stretch after the acetylation which indicates the substitution of hydroxyl group by acetyl group. On the other hand, the emergence of C=O stretch of the ester group and C-O stretch of acetyl group can be observed which indicates the formation of cellulose acetate. TGA and DTA also shows enhanced thermal stability of cellulose acetate prepared in 16 hrs acetylation period. Increasing the reaction time to 24 hrs and 32 hrs resulted to significant decrease in thermal stability. SEM images revealed the deterioration on the physical structure of cellulose after 24 hrs acetylation.
Abstract: Cellulose nanocrystals (CNC) were extracted from corn cob and synthesized by alkaline treatment using 3 wt% sodium hydroxide (NaOH). Acid hydrolysis with 64 wt% sulfuric acid (H2SO4) at different reaction times (30, 45, 60 min) was performed to obtain CNC solutions. CNC was evaluated as a reinforcing agent in natural rubber (NR) at CNC loadings from 1-5 wt%. Gamma-ray radiation was used as vulcanization method and varied at 10 and 20 kGy. The tensile modulus and tensile strength of NR vulcanizates increased with addition of CNC and contents. In addition, radiation by gamma ray impacts the mechanical performance, where CNC/NR composites vulcanized with higher dose of radiation of 20 KGy were found to have the higher values in tensile strength, elongation at break, and modulus than with 10 KGy. Moreover, the tensile strength and elongation at break of the composites after aging were found to slightly increase due to post-curing during the aging process.
Abstract: In order to produce metal matrix composites (MMCs), aluminium powder was milled for a total time of 5 hours. Aluminium nitride was the ceramic reinforcement chosen to improve the mechanical behaviour of the aluminium matrix. In order to form it in situ, an ammonia gas flow was incorporated during a certain period of the milling process. Two different conditions of NH3 flow during milling were studied: short time (5 min) and long time (3 h). In both cases, milling started with a 2 h period of mechanical alloy in vacuum (5 Pa). Then, NH3 was incorporated during the stipulated time (5 min or 3 h), after which the milling process continued under vacuum to complete 5 hours. The powders were cold pressed and vacuum sintered to produce compacts. The results showed that compacts with better mechanical properties are obtained when short duration ammonia gas flow is used. The use of short flows provides good control of the amount of ceramic second phases formed. This allows the produced compacts to reach ultimate tensile strength higher than 400 MPa.
Abstract: Since CNTs (carbon nanotubes) have excellent electrical and mechanical characteristics, their application as fillers for polymer matrix composites is expected to have great potential. The purpose of this study is to clarify the effect of CNT’s crystallinity quality, which is given by high temperature treatment (i.e. annealing), on the properties of CNT/polymer composites. In this study, double wall type CNT (DWNT) and multi wall type CNT (MWNT) were used and heat treated at up to 2000°C to achieve highly improved crystallinity. Electrical and mechanical properties of the CNT/polymer composites were compared with the various CNT’s crystallinity qualities as measured by ID/IG ratios. As a result, although the composites with higher quality CNTs showed considerably lower surface resistivities, however the same composites had lower Young's modulus and tensile strengths. The reason is thought to be that the high quality CNT has low surface activity and weak adhesion between the polymer and the CNT surface. This suggests that CNTs with higher quality do not always contribute to the improvement to the properties of CNT/polymer composites.
Abstract: Aluminum tri-hydroxide (ATH) and montmorillonite (MMT) are capable to enhance flame retardancy of glass fiber reinforced polymer (GFRP). Nevertheless, the combination of both flame retardant fillers on changes in the mechanical properties of GFRP is not yet known. The characterization of flexural strength and scanning electron microscope (SEM) observation on GFRP composite has been done. The result of flexural properties testing shows that the addition of ATH or MMT or a combination of both on the GFRP causes a decrease in flexural strength. GFRP with increased ATH loading causes an increase in elastic modulus. Contrarily, the MMT addition causes a decrease in the elastic modulus of the GFRP composite. SEM results on the fractured samples show that the high content of ATH or MMT in the UP tends to agglomerate thus showing visible holes that were formed from the filler particles pulled out from the matrix.
Abstract: Recycled poly (ethylene terephthalate) or R-PET is conventionally melt blended with polycarbonate with the presence of chain extender in order to produce polymer blend that provides good mechanical properties and cost effectiveness. This research was carried out to improve properties of such a blend by compounding them with silane treated hollow glass microspheres (HGMs), which mixing procedure was emphasized how it could affect mechanical properties. R-PET/PC/HGM composites of a fixed composition were melt compounded with three different mixing procedures. It was found that the compounding HGMs with PC and then R-PET obtained the most rigidity specimens than the all-in-one compounding or the compounding HGMs with R-PET and then PC. Silane treated HGMs were well distributed in the polymer matrix presenting good interfacial adhesion. However, the notched impact strength of all composites were inspected to be in the same range.
Abstract: The study of vibration-damping factor on unsaturated polyester resin reinforced glass and kenaf fiber has been performed. Two variations of glass and kenaf fibers were made based on fiber volume fraction (Vf) and ratio of glass to kenaf fiber at Vf of 25 %. The measurement of the samples was to obtain the value of the vibration-damping factor and the elastic modulus. The result shows that the vibration-damping factor decreases proportionally to the addition of fiber. Increased stiffness is evidenced by an increase in elastic modulus along with an increase in fiber content. According ratio of glass to kenaf fiber, the vibration-damping factor decreases proportionally with the increasing of glass fiber content. Increased kenaf fiber content causes an increase in vibration-damping factor, a decrease in elastic modulus, and lead to decreased in stiffness of the hybrid composite.
Abstract: In this work, we present the novel robust material, modified natural rubber (NR) composites filled with gold nanoparticles (AuNPs). To investigate its outstanding properties, dielectric, electrical and mechanical properties of NR and modified NR composites filled with gold nanoparticles (AuNPs) were studied. The NR and all composite films were prepared by using solution casting method. The size of the synthetic AuNPs was analyzed by Transmission Electron Microscope (TEM) technique. The dispersion of AuNPs fillers within the NR matrix was investigated by scanning electron microscopy (SEM). Dielectric and electrical properties of NR composites were analyzed as function of filler concentration and frequency in a range of 100-105 Hz, observed with the LCR analyzer. Elastic modulus of all samples was evaluated by a strain gauge set up. It was found that the dielectric constant is inversely related to the frequency. Moreover, the dielectric constant and the electrical conductivity strongly increase in proportional to the AuNPs filler content. In comparison at AuNPs concentration of 0.0010% by weight, it was observed that the dielectric constant of NR composites is eight times larger than the pure NR, while the mechanical properties of the NR composites slightly increase in proportional to the AuNPs. As consequence, the interfacial surface area significantly affects the electrical and mechanical properties of those NR composites.