Papers by Keyword: Unsaturated Polyester Resin

Abstract: Natural fiber has been used as a heat-insulating material for ages in Indonesia. On the other hand, there is plenty of sago pith waste (SPW) available since the nation is the world's top producer of sago starch. In this study, SPW was utilized in manufacturing composite materials, and their thermal properties were investigated. The unsaturated polyester resin was used as the matrix, and the composites were manufactured in three different SPW volume fractions: 20%, 30%, and 40%. The thermal properties were measured using a test setup box equipped with a 100 W lamp as a heat source. The thermocouple sensor DS18B20 was utilized to measure the necessary temperatures to determine the thermal conductivity of the composites. An Arduino microcontroller system connected to a computer was applied to manage the reading from the temperature sensors. The thermal conductivity was measured according to the temperature of the heat source. It was discovered that as the SPW volume fraction in the composites increases, thermal conductivity does as well at any lamp temperature. The measured thermal conductivity varied considerably; thus, taking the average may not be reliable as the error bars were larger than the average values. Further analysis of the measured temperature development revealed that the accurate thermal conductivity values lie within a very narrow range of lamp temperature, 50 °C < T_lamp <60 °C.

Abstract: As the largest sago starch producer in the world, Indonesia has a very large amount of leftover waste from sago starch production, which is usually called sago pith waste (SPW). This large amount of waste has enormous potential to be utilized for other benefits and purposes. In this study, SPW was tested for use in manufacturing composite materials. The aim is to investigate the detailed properties of the composites that have SPW particles in them. Unsaturated polyester resin was used as the composite matrix, and three different SPW percentages were tested: 20%, 30%, and 40%. Tensile tests were performed on the composites, and three specimens were prepared for each SPW percentage variation. All nine specimens tested failed at the maximum given load. Either the maximum strain before the specimen failed or the ultimate tensile stress decreased with larger SPW percentages used in the composites. Further, SEM micrograph examination of selected fractured specimens successfully revealed the behavior and the morphology of SPW particles on the fractured surface.

Abstract: Indonesia generates abundant sago pith waste (SPW) because the country is the world's largest producer of sago starch. Although many efforts and studies have been devoted to processing this waste, SPW has not been utilized properly, and a large amount of SPW remains unprocessed and thrown away. On the other hand, increasing noise levels have become a problem in Indonesia due to the rapid industrialization in recent years. In this study, SPW is tested for use as a sound-absorbing material by first converting it into composite materials. The composites were manufactured by using unsaturated polyester resin mixed with SPW particles in three different volume fractions: 20% SPW, 30% SPW, and 40% SPW. SEM micrographs were performed to observe the morphology of the SPW particles and the composites. SEM micrographs revealed honeycomb structures of the SPW, and the average diameter of dried sago starch particles was observed to be around 5 μm. Further SEM examination on the composite specimens only found pores and holes previously occupied by sago starch particles, while the honeycomb structures were difficult to find except for the specimens with 40% SPW. The acoustics tests of all composite specimens were conducted using a set of impedance tubes between 0 and 6000 Hz. The plot lines of the coefficient of sound absorption are complex, and the SPW volume fraction that produces the best coefficient is affected by the sound frequency. However, the composite specimen with 30% SPW appears to have the best overall sound absorption properties.

Abstract: This research focused on the effect of initiator and accelerator amounts on mechanical properties of unsaturated polyester resin (UPR). Methyl ethyl ketone peroxide (MEKP) and cobalt octoate (CoO) were used as an initiator and an accelerator, respectively. The amount of each chemical was varied from 1, 1.5 to 2 phr. In each batch, UPR, MEKP and CoO were mixed, casted and allowed for curing at room temperature for 24 hours. Mechanical properties of the cured samples were then studied. The results indicated that the effects of MEKP and CoO amounts on flexural properties and impact resistance were greater than those on hardness. It was found that UPR samples prepared by using the same ratio of MEKP and CoO exhibited overall mechanical properties better that those prepared with different MEKP and CoO ratios. When all mechanical properties were considered, the results suggested that the best overall mechanical properties were achieved when MEKP 1.5 phr and CoO 1.5 phr were employed.

Abstract: Concerning the importance of composite material for multi-purpose applications, an attempt has been taken to synthesize composites using natural fiber with unsaturated polyester resin. Since the use of synthetic polymer plays a key role in polluting the environment, we have used natural fiber (banana fiber) as an alternative source. Our approach dealt with the preparation of reinforced composites by hand lay-up technique using 20 % banana fiber (by weight) as reinforcing materials. Several techniques were applied to characterize synthesized composites e.g. universal testing machine (UTM), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). UTM facilitated the measurement of the tensile strength (TS), tensile modulus (TM), elongation at break (EB), bending strength (BS), and bending modulus (BM) while functional groups were confirmed by FT-IR and the morphology of the composites was investigated by SEM. Observed results revealed that the TS, TM, BS, and BM followed an increasing fashion of 100%, 53%, 75%, and 55% respectively with respect to the matrix materials. On the other hand, the EB of the composite reduced drastically by 50%. Hence, higher mechanical properties were obtained for the banana fiber reinforced composites (BFRC) than the unsaturated polyester resin (UPR) matrix.

Abstract: Jute fabrics reinforced Polypropylene (PP) matrix composite was fabricated by compression molding and Unsaturated Polyester Resin (UPR) matrix composites were also fabricated by hand lay-up technique. The fiber content of the composites was 40% by weight. Mechanical properties between two types of composites were compared. Tensile Strength (TS), Tensile Modulus (TM), Elongation at break (Eb%) , and Impact Strength (IS) of the jute fabrics/PP composites were found to be 47 MPa, 1.2 GPa, 13% and 8 kg/cm, respectively. On the other hand, TS, TM, Eb%, and IS of the jute fabrics/UPR composite were found to be 43 MPa, 1.3 GPa, 10% and 6 kg/cm, respectively. It was found that both composites showed almost similar mechanical properties. After tensile testing, fracture sides of both types of the composites were studied by Scanning Electron Microscope (SEM) and the results revealed poor fiber matrix adhesion for jute fabrics with PP and UPR. The fabricated composites became partly biodegradable because of jute (natural fiber) and mechanical properties of both types of composites showed promising results for commercial applications.

Abstract: This paper represents a comparative study of the different weave structures of jute woven fiber reinforced unsaturated polyester resin (UPR) composites. The weave structures were selected as plain (1/1), twill (2/1), twill (3/1) and basket (2/2). Composites (50% fiber by wt.) were prepared by using hand lay-up technique. The mechanical properties such as tensile strength (TS), bending strength (BS) and impact strength (IS) of the composites were evaluated and compared. It was found that basket weave/UPR based composite showed the highest mechanical properties. The optimum value of TS, BS, TM, BM and IS of the composite were found to be 47 MPa, 80 MPa, 1.4 GPa, 4.8 GPa and 27 KJ/m².To find out the effect of yarn density on mechanical properties of the composites, 2/1 twill structure was selected and found significant improvement in the mechanical properties with the increase of Ends/Inch (EPI) and Picks/Inch (PPI) in the fabric. Water uptake and degradation behavior in aqueous medium of the composites was also observed.

Abstract: E-glass fiber mat reinforced Unsaturated Polyester Resin (UPR)-based composites were fabricated by conventional hand lay-up technique. The fiber content was varied from 5 to 50% by weight. Mechanical properties (tensile and bending) of the fabricated composites were investigated. The tensile strength (TS) of the 5% and 50% fiber reinforced composites was 32 MPa and 72 MPa, respectively. Similarly, tensile modulus, bending strength and bending modulus of the composites were increased by the increase of fiber loading. Interfacial properties of the composites were investigated by scanning electron microscopy (SEM) and the results revealed that the interfacial bond between fiber and matrix was excellent. Keywords: Unsaturated Polyester Resin, Mechanical Properties, E-glass Fibers, Composites, Polymer.

Abstract: Natural fiber reinforced polymer composites are generally lower in mechanical performance compared to synthetic fiber reinforced polymer composites. However, this disadvantage can be improved via chemical modification of the natural fiber and hybridization with synthetic fiber. In this study, kenaf bast fiber was used as reinforcement in unsaturated polyester composites. It was subjected to chemical modification with maleic anhydride at various treatment time i.e. 60, 90 and 120 minutes prior to composites production. The untreated and MA treated kenaf bast fiber were hybridized with 10 weight percent of glass fiber to produce kenaf bast/glass fiber reinforced unsaturated polyester composites. The effect of treatment time on weight percent gain and functional group changes via infra-red spectra of kenaf bast fiber were investigated. The effect of treatment time on tensile properties of kenaf bast fiber and kenaf bast/glass fiber reinforced unsaturated polyester composites were also studied. It was revealed that the weight percent gain of kenaf bast fiber increased with the increasing of treatment time. The increasing of treatment time resulted in the enhancement of tensile strength and modulus of kenaf bast fiber and kenaf bast/glass fiber reinforced unsaturated polyester composites which were attributed to the presence of C=C bonds of maleic anhydride and has been proven through fourier transform infrared spectrum.

Abstract: Kenaf bast fibers were prepared into two types as untreated and maleic anhydride (MA) treated. Unsaturated polyester (UPE) resin was used as matrix and applied onto the kenaf bast fibers using hand lay-up method. Transverse and longitudinal flexural properties of unidirectional long kenaf bast fiber reinforced unsaturated polyester composites were performed and the effect of fiber modification and loading were studied. It is found that the transverse flexural strength of both types of composites decreases with the increasing of kenaf loading. Contrary, longitudinal flexural strength of both composites increases with the increasing of kenaf loading. Improved transverse and longitudinal flexural properties are shown by MA treatment of kenaf bast fiber. The interactions between fiber and matrix of fractured flexural surface were also observed by scanning electron microscope (SEM).