Key Engineering Materials Vols. 594-595

Abstract: Currently, the recycled rubber widely being used in rubber technology. Due to difficulty on reprocessing techniques, the vulcanized rubbers being a big problem in the recycled field. One of the main forms of discharge rubber is to apply as fuel to generate electricity and steam, this process is still in use but creates a new problem of air pollution and is also a low value to recovery process of the rubber waste [. Polymer compounds are being used extensively in numerous applications such as roofing and mulch product. A rubber blends can offer a better properties that gives high performance in application area that being used [.

Abstract: A Possibility of R6M5 High-Speed Steel Strengthening by Finishing Plasma Strengthening(FPS) Method to Application of Sic Thin Film Coatings were under Research. by Scanning Electronmicroscopy and X-Ray Analysis Conducted a Comparative Study of the Structure, Phase and Chemicalcomposition before and after Application of Sic Thin Film Coating of R6M5 High-Speed Steel Surfacelayer. it is Experimentally Stated, that the Coverage of Sic Applied Method FPS Consists of Fineglobular Shape at the Size of 100-300 Nm. Determined that the Microhardness of R6M5 Steel Surfaceafter Application Sic Coating Increased Almost to 2.5 Times Comparing to Original. it is Shown Thatthe Application of Sic Thin Film Coating by FPS Method is a Promising Highly Effective Method Ofcutting Tools Surface Strengthening Made from High Speed Steels.

Abstract: Cure characteristics and crosslink density of virgin acrylonitrile butadiene rubber/recycled acrylonitrile butadiene rubber (vNBR/rNBR) blends were studied. Three different size ranges of rNBR particles, i.e., 150 - 350 μm, 2.0-15.0 mm, and 5-10 cm were used in this study. The vNBR/rNBR blends with blend ratios of 95/5, 85/15, 75/25, 65/35, and 50/50 were prepared using a two roll-mill at room temperature. The characterization results of the blends show that scorch time, t₂, of the vNBR/rNBR blends decreased with increased rNBR content as well as decreasing sizes of rNBR particles while cure time, t₉₀ of the vNBR/rNBR blends increase with increased rNBR content as well as increasing sizes of rNBR particles. Among all blend ratios, the vNBR/rNBR blends with smallest size of rNBR particles exhibit lowest minimum torque (ML) compared with the bigger particle sizes of it in vNBR/rNBR blends which resulted in more efficient processing. The maximum torque (MH) of all vNBR/rNBR blends shows the inclining trend with increased rNBR. The cross-linking density of vNBR/rNBR blends also show an increasing trend with increasing rNBR content.

Abstract: This study is to determine the properties and characterization of silicon carbide via grinding and heat treatment process. In this study, the raw materials used were waste glass and graphite powder. Silicon carbide was produced by milling and mixing waste glass and graphite powder in different grinding mills; planetary mill and ring mill. The samples were then heat treated at 700 °C for 1 hour soaking time. Two types of characterization procedures were completed to determine the properties and microstructure of silicon carbide. Formation of silicon carbide was only formed through grinding by planetary mill but not ring mill. This may due to the grinding mechanism of both mills. Due to the simple and low cost of raw material to form silicon carbide, silicon carbide has high potential to be one of the commercialized products. It has the potential in reducing waste and improves the environment quality.

Abstract: This paper study the effective toughening of polymer nanocomposites in order to have a balance stiffness, strength and toughness by incorporation of EVA as impact modifier and organoclay as a filler. In this research, rubber toughened PA6/HDPE blends nanocomposites were blended with 1 to 5 phr of ethylene vinyl acetate (EVA) with incorporation of 5wt% organoclay (MMT) in the presence of HDPE-g-MAH as compatibilizer. The mechanical properties of the samples such as tensile test and tensile modulus were measured by universal tensile machine whiles impact strength and hardness was measured using Izod Impact Tester and Rockwell hardness tester. The composites were characterized by Fourier Transform Infrared (FTIR) spectrophotometer and Thermogravimetric Analyzer (TGA). The results exhibited enhancement of mechanical properties with incorporation of 1 phr EVA but slightly decreased for further addition of EVA content. FTIR analysis showed that both samples with and without EVA presented almost the same trend. TGA stability exhibit samples containing EVA showed lower stability than sample with EVA. Conversely, addition of EVA greatly increases the impact strength as well as improved the toughness of the composites.

Abstract: Biopolymer foam was prepared by the reaction of bio-monomer based on vegetable oil with commercial Polymethane Polyphenyl Isocyanate (Modified Polymeric-MDI) and titanium dioxide (TiO₂). The acoustic study of biopolymer foam with 2.5% TiO₂ loading was examined by impedance tube test according to the ASTM E-1050 and laminated with three types of textile such as polyester, cotton and single knitted jersey. It was revealed that the thicker the fabric the higher the sound absorption coefficient (α) at low frequency level. The higher the number of layers or thickness of the fabric, the sound absorption through the fabric increases at low frequency but after the maximum it remains almost unaltered. Three layer of cotton fabric gives maximum α approximately equal to 0.578 which is 1.472mm thickness at low frequency level of 1000-2000Hz and single knitted jersey gives maximum α at 3^th layer. Meanwhile , the α of biopolymer foam with 2.5% TiO₂ loading laminated with polyester fabric approximately equal to 1 at lower frequency level of 1000-2000Hz with lower thickness that is 0.668mm. Polyester fabric with lowest thickness shows better α at lower frequency level due to the structure of the fabric. The relationships among the fiber properties such as fiber density, fiber diameter, fibrous material layer were considered as a factor that influences the sound absorption property.

Abstract: Titanium dioxide represents an effective photocatalyst for water and air purification and for self-cleaning surfaces. The purpose of this study is to determine sound absorption property of polymer foam of high doping of Titanium Dioxide (TiO₂) which are 20%, 40%, 60%, 80% and 100%. The acoustic study of the samples was measured by using impedance tube test according to the ASTM E-1050 to determined sound absorption coefficient (α) and noise reduction coefficient method (NRC). The highest α is 0.999 observed from the polymer foam doped with 60% of TiO₂ at high frequency level of 4000 Hz. Meanwhile, the highest doping of TiO₂ polymer foam shows remarkable characteristic of low level frequency absorption at 2000 Hz. Thus, different percentage of TiO₂ doped in polymer foam can be used successfully to alter the characteristic of sound absorption property in a systematic way according to the request application.

Abstract: A Red Meranti Wood Dust (RMD) act as a filler for polymer foam composite has been investigated and proved to have ability to absorb sound. In this study, treatment of wood dust with and without acid hydrolysis named as WDB and WDA respectively was use as filler. This study was developed to compare the ability of sound absorption based on treated filler and particle size of wood dust. By choosing the size of 355 μm, three different percentage has been selected which is 10%, 15% and 20% for both conditions. These samples has been tested by using Impedance Tube test according to ASTM E-1050 for sound absorption coefficient, α measurement and Scanning Electron Microscopy (SEM) for determine the porosity for each samples. 10% loaded of WDB as filler gives highest sound absorption coefficient of 0.999 at 4015.63 Hz. Meanwhile for 20% loaded of WDA gives 0.997 at 3228.13 Hz. When comparing the sound absorption coefficient for both sounds absorbing materials, WDB-polymer foam composite RMD showed higher value of sound absorption coefficient, α at higher frequency as compared to WDA-polymer foam composite.

Abstract: The aim of this study was to optimize the mixing process of a composite solder fabricated via powder metallurgy route, before details study were conducted in the next stage. Powder of Sn, Cu and Si₃N₄ were carefully weighted, mixed and blended in a mechanical alloying machine. The speed of rotation for the jar was kept constant while the time of mixing was varied. Si₃N₄ were added to the Sn-0.7Cu solder as reinforcement. Upon completion of mixing process, the mixed powders were later compacted into a thin disc. The compacted samples were then sintered in a horizontal tube furnace. Microstructural examinations by using SEM were conducted in order to analyze the distribution of Cu and Si₃N₄ particles. With the assistance of ImageJ software, average particle distributions were calculated. Results showed that the best particle distributions were achieved when the mixed powder were blended for 6 hours.

Abstract: Inorganic filler, calcium carbonate (CaCO₃) was used as filler in the polypropylene (PP)/ ethylene propylene diene terpolymer (EPDM) composites. The composites were compatibilized with Maleic anhydride grafted polypropylene (MAPP) in order to improve the properties. The addition of CaCO₃ at has increased the modulus of elasticity of composites but tensile strength and elongation at break of uncompatibilized composites decreased with increasing CaCO_3. The result shows that the compatibilized composites higher tensile strength and Modulus of elasticity but lower elongation at break compared to uncompatibilized composites. At 10 wt% CaCO3 showed higher tensile strength of uncompatibiled and compatibilized composites. The morphology study from SEM analysis reveals that compatibilized composites show better interfacial adhesion between the filler and the matrix. The addition of MAPP has improved crystallinity of compatibilized composites.