Materials Science Forum Vol. 961

Abstract: In this research, alkali treated zallaca fibre reinforced with high density polyethylene (HDPE) composites are subjected to water immersion tests in order to study the dimensional changes and flexural properties of composites. Composites were frabricated using compression molding method with zallaca fiber content of 30% vt. Composite specimens were immersed under three different solution included distilled water, sea water and acidic solutions for 2 months at room temperature. The highest dimensional changes was recorded for composite immersed in seawater followed by acidic solution and distilled water. The dimensional changes of Zallaca fibre reinforced HDPE in different solution were found to follow a Fickian behaviour. Alkali treated fiber composites after immersion has lower results both in dimensional changes and its slope than untreated fiber composites in different aquaeous environment. The severe degradations are observed by using Scanning Electron Microscopy (SEM) that showed microcracks growth, and degradation of interfacial region between fiber and matrix. Flexural properties of composites decrease after immersion stage in different values.

Abstract: Banana fiber is agricultural waste that can be obtained after harvesting the fruit with no additional cost. Banana fiber has major drawbacks in composite product such as low interfacial bond strength between fiber and matrix as comparison with synthetic fiber. The aim of this research is to investigate the effect of alkaline concentration treatment conditions on tensile strength and flexural strength properties of banana fiber reinforced polyester resin composite. Banana fiber was treated using sodium hydroxide (NaOH) treatment. There are four variations of NaOH concentration treatment, 0%, 5%, 10% and 15% for 1 hour immersion time at room temperature. Hand lay-up technique was used in composite fabrication with 40% fiber volume fraction at random orientation of banana fiber. Based on this research result can be concluded that composite with NaOH treatment has a better tensile strength and flexural strength if compared with untreated fiber. Banana fiber composite treated with 5% NaOH concentration show the highest tensile and elasticity modulus, and also flexural strength and flexural modulus better compare the other treatment. Banana fiber composite specimens on macro picture observation show that the untreated fiber has a lot of fiber pull-out, it is occur the weak interfacial bond between matix and fiber. On the other hand, the treated banana fiber composite shows a slight fiber pull out, because composite has high interfacial bond between matrix and fiber.

Abstract: The aim of this study is to investigate the behavior of banana fiber (BF)-low-density polyethylene (LDPE) composite fracture toughness. The LDPE pellets are transformed into powder form which is then functioned as a matrix reinforced with banana fiber (BF). The composites were formed by injection molding techniques which are followed by atmospheric-pressure annealing at 90°C for 24 hours. The composite fracture toughness behavior was evaluated using the essential work of fracture (EWF) approach. The results show that fracture toughness which is characterized by essential fracture work (w_e) value increases by the presence of BF up to 5 wt.%. However, the w_e value starts to decrease in the composite with BF content of 6 wt.%. There is a mismatch about the phenomenon of non-essential fracture work. Stress-whitened zones can be seen and observed but non-essential fracture work based on curves is a negative value.

Abstract: The low cost of ABS polymer and natural polymer chitosan offer attractive chemical and physical properties for direct methanol fuel cells (DMFC). In this contribution, investigation of blend membrane made of ABS and chitosan, and their characterization for water uptake, swelling degree and ion exchange capacity (IEC) and methanol crossover are reported. This membrane was also assessed for its intermolecular interactions and thermal stability using FTIR and TGA compared to the pristine membrane. The water absorption and IEC values were affected by membrane network structure. The polymer blend had better thermal stability and a reduction of methanol permeability, this indicated the viability of utilization these materials as polymer electrolyte membrane in DMFC

Abstract: Making scaffolds for bone repair is increasingly needed. The material used can be in the form of molten material or powder. For powder materials, Direct Laser Melting technology can be used so that the development of powder material deposition methods is needed. This is because there is a weakness in the deposition method which is assisted by gas pressure. This study uses two types of nozzles, the first type is made of brass with diameters 0.5, 0.8 and 1.0 mm, while the second type is made of glass with a nozzle mouth diameter of 1.0 mm. The powder material used is a polyester resin with a diameter of 5-15 microns in black, and diameter 7-75 microns in red. The nozzle containing the powder is vibrated so that a flow will occur. This flow characteristic will affect the form of deposition that occurs. Powder flow on the nozzle made of brass and glass shows a similarity to the 1.0 mm nozzle diameter. For nozzle diameter smaller than 1.0 mm, the effect of grain size affects flowability. The smoothness of the surface affects the nature of the powder flow. On a smooth glass surface, the friction force between the powder and the wall of the nozzle is small, so that for the small powder size the flow cannot be controlled. The best deposition form is obtained at a frequency of 950 Hz with a brass nozzle and 1.0 mm diameter.

Abstract: One aspect that needs to be considered in the application of asphalt pavement is the fact that asphalt is a non-renewable resource which requires constant maintenance throughout its lifetime. Thus, developing a mix with asphalt contents reduced to the minimum is a challenge in and of itself. Latex, in this case, would seem to be potentially viable additives. The aim of this research is to investigate the effects of using latex as an additive to minimize the use of asphalt in asphalt concrete wearing courses (ACWC). Four varying amounts of latex were mixed with asphalt at 0%, 2%, 4%, and 6% of the total weight of an asphalt binder. A wet process was then employed to blend the mixtures together. Afterward, the latex-asphalt mixtures were added to an aggregate to form various mixtures ranging from 5% to 7% of the aggregate and the incremental weight of 0.5% of the latex-asphalt ACWC. For each latex-asphalt-aggregate mixes, the optimum binder content was determined based on stability, flow, Marshall quotient, voids in the mineral aggregate (VMA), voids in the mixture (VIM) and voids filled by the binder (VFB). The results of this experiment indicated that the addition of latex reduces the need for asphalt contents.

Abstract: Inorganic polymer materials known as geopolymer-based materials are always interesting topics for researchers. Geopolymer is environmentally friendly material which has been potential applications for many different fields such as technical materials, building materials, insolation or refractories, and others. This study used ash of brickyard (AB) as a raw material for geopolymerization process to develop novel materials with high porosity. AB is industrial waste of the brick factories that need to be managed to reduce their negative impact to the environment. AB contains high alumino-silicate resources were mixed with sodium hydroxide solution for 10 minutes to obtain the geopolymer pastes. Sodium hydroxide solution was used as an alkaline activator to form geopolymer paste. The geopolymer paste was filled into 5-cm cube molds according to ASTM C109/C109M 99, and then cured at room temperature for 28 days. These products were then tested for compressive strength, volumetric weight, and water absorption. Results indicated that the material can be considered lightweight with a compressive strength at 28 days that are in the range of 8.1 to 15.4 MPa, volumetric weight around 600kg/m³ and water absorption is under 210.65 kg/m³. The properties of geopolymer products were also determined by analytical techniques that included mineral composition by X Ray Diffraction (XRD) and microstructure by scanning electron microscope (SEM).

Abstract: Garbage is a serious problem if it is not managed properly, both organic and non-organic. Inorganic waste, for example, plastic, metal, glass, and charcoal from coal combustion are difficult to decompose in the soil. HDPE (high-density polyethylene) plastic is one type of inorganic waste that is difficult to decompose, but this plastic can be recycled. The objective of the study is to develop light cement blocks by using the waste of HDPE, coal bottom ash and cement. The research guide was referred to SNI (Indonesian National Standard). The SNI-03-6825-2002 is for testing of the compressive strength and SNI 03-0349-1989 for the testing of the water absorption. The size of the specimen was 5 x 5 x 5 cm. In this study, the compositions of HDPE: coal bottom ash were varied by 70%: 0%, 60%: 10%, 50%: 20%, and 40%: 30%. The Holcim cement was 30% of the volume fraction. Testing was conducted after the specimens stay in 7 and 28 days. For the 7 days old of specimens, the highest compressive strength has resulted from 50%:20% composition with the value of 5.88 N/mm2. For the 28 days old specimens, the highest compressive strength was 8.34 N/mm2. The lowest water absorption test was delivered by the more coal bottom ash in the composition of 40%:30%. It was 16.971%. The more coal bottom ash, the less water absorption. The mean of specimens density was 1.076 gr/cm3. The result of the research shows that recycles HDPE and coal bottom ash as concrete block meet the required strength.

Abstract: The significance of this research is to find out the effect of adding Crumb Rubber Motorcycle Tire Waste (CRM-MTW) on asphalt concrete wearing course (ACWC) mix. Two sizes of CRM-MTW that are used are CRM that passes filters identified as numbers 50 and 100, while the contents of the CRM-MTW are 0%, 0.5%, 1%, 1.5%, 3%, 4.5%, and 6% of the aggregate weight. Marshall Method is used in this research. The analysis is based on Marshall parameters namely, stability, flow, Marshall Quotient (MQ), Void in the Mix (VIM), Void in the Mineral Aggregate (VMA), and Void Filled Asphalt (VFA). The result of this research indicates that the size of CRM-MTW, No. 50 and No. 100, affects Marshall stability of conventional asphalt mix. Best CRM-MTW addition is CRM-MTW No. 100 with the content of 1%.