Performance of Rubber Seals for Cable-Based Tsunameter with Varying Ethylene Propylene Diene Monomer and Filler Content Riastuti Fidyaningsih, Dewi Kusuma Arti, Herri Susanto, Ade Sholeh Hidayat, Mahendra Anggaravidya, Akhmad Amry, Tika Mustika, Muslim Efendi Harahap, Vian Marantha Haryanto, Mochammad Dachyar Effendi Journal of Composites Science, 2025 This study evaluates the performance of ethylene propylene diene monomer (EPDM) composites for rubber sealing applications in a cable-based tsunami system. Rubber composites were prepared using EPDM rubber with varying monomer and filler content to determine the most suitable composite. Mechanical characterization reveals that the composition of EPDM and the amount of filler loading influence the mechanical properties. Dynamic mechanical analysis shows that ethylene and 5-ethylene-2-norbornene (ENB) content influence the glass transition and viscoelastic behavior of the composite. Thermal analysis of rubber composites using EPDM containing 70% ethylene and 5% ENB indicates no change in thermal stability due to prolonged immersion in seawater. Visual inspection using a microscope reveals no cracks on the surface of the rubber seal after the pressure chamber test for rubber composites utilizing EPDM with 70% ethylene and 5% ENB. It was shown that EPDM containing 70% ethylene and 5% ENB, with optimal reinforcement with 80 phr carbon black, exhibits the best performance for rubber sealing applications in subsea environments.
Use of Ni/CNT Particles as Additive Fillers in Ebonite Bipolar Plates for Proton-Exchange Membrane Fuel Cells Moh Hamzah, Lailatul Qadariyah, Agung Purniawan, Ade Sholeh Hidayat, Nidya Chitraningrum, Fadlilatul Taufany ACS Omega, 2024 Composite-based bipolar plates are a chance to substitute graphite and metal bipolar plates because of their corrosion resistance and better chemical and mechanical properties, but they still have various electrical conductivity properties. One of the problems is the loading of filler that depends on matrix types which will affect the electrical conductivity of bipolar plates; ebonite has potential as a matrix in composite bipolar plates because it is obtained from elastomer or rubber. In this work, nickel and carbon nanotubes (CNT) that have a high electrical conductivity will be investigated as additive fillers on graphite particles to enhance the electrical conductivity of ebonite bipolar plates. The formulation and characterization of ebonite bipolar plates with graphite and graphite Ni/CNT and their various contents are the main objectives of this research. Characterization by scanning electron microscopy (SEM) for identification and morphology of compounds and ebonite bipolar plates and Raman spectroscopy for identification of the type carbon in Ni/CNT was performed. Some tests such as bending/flexural tests, corrosion tests, and resistance testing for interfacial contact resistance were conducted to study the properties and optimum of the composite materials. In this research, Ni/CNT particles were added as additive fillers with graphite to enhance the electrical conductivity of fillers in ebonite bipolar plates of proton-exchange membrane fuel cells and their impacts were studied. By through-plane testing, graphite fillers were added in ebonite bipolar plates with 65–75% w/w content, achieving electrical conductivity values from 22.3 to 34 S/cm. This is still below the technical target set by the US DOE for composite bipolar plates. But by adding 30% Ni/CNT filler contents in ebonite bipolar plates at various filler contents from 65% to 75% w/w, one can achieve electrical conductivities from 104.35 to 165.52 S/cm. Only 65% w/w filler with 30% Ni/CNT can meet the technical targets such as a bending/flexural test value of 25.58 N/mm2, a corrosion test value of 0.894 μA/cm2 (Icorr), and an interfacial contact resistance value of 3.09 mΩ cm2. Further improvements are needed based on fuel cell applications, as indicated by some additional data that did not meet technical targets.
Two Sesquiterpenes from n-Hexane Fraction of Curcuma soloensis Rhizomes and Their Antimicrobial Activities Hartiwi Diastuti, Ari Asnani, Puji Lestari, Teni Astuti, Naela Nurmalia, Ade Sholeh Hidayat Jurnal Kimia Valensi, 2024 Curcuma soloensis is one of the medicinal plants that has the potential to be a source of bioactive compounds. The antimicrobial study of the bioactive compounds from C. soloensis was still limited. This study aimed to isolate the bioactive compounds from C. soloensis rhizomes and to evaluate their potential as antimicrobial agents. C. soloensis rhizome extraction was done using the maceration method with acetone and then fractionated with n-hexane: methanol (1:1). The compounds were separated and purified using vacuum liquid chromatography and radial chromatography. The structure of the isolated compounds was determined using the nuclear magnetic resonance (1H and 13C NMR) spectroscopy analysis and comparison with literature data. Antimicrobial activity assays of the extract, n-hexane fraction, and isolated compounds were carried out by microdilution methods against Escherichia coli, Staphylococcus aureus, Candida albicans, and Malaszezia furfur. Two bioactive compounds from the n-hexane extract of C. soloensis rhizome have been isolated: ar-curcumene and ar-turmerone. Antimicrobial test results on acetone extract, n-hexane fraction, and isolated compounds showed that ar-turmerone had the highest activity against S. aureus with a MIC value of 15.6 μg / mL. In comparison, ar-curcumene showed the same activity against all test microbes with a MIC value of 62.5 μg / mL. This study showed that secondary metabolite compounds of C. soloensis rhizomes have the potential to be developed as antimicrobial agents.
Epoxy - Glass microballoon syntactic foam: Study the effect of composition and microballoon type on density, porosity, and compressive strength Jayatin, Suryadi, Dewi K. Arti, Ade S. Hidayat, Riastuti Fidyaningsih Aip Conference Proceedings, 2024 Density and compressive strength are two important properties in the manufacture of syntactic foam materials. Syntactic foams are composites that are filled with hollow particles (microballoon). In this research, epoxy resin and glass microballoon were used as the main component. Two ways are usually done to get the syntactic foam properties as desired. The first way is by adjusting the composition of the microballoon and the second way is by choosing the type of microballoon. The effect of two types of microballoons with different crushing strengths (K15 and iM16K) on density, porosity, and compressive strength was carried out in this study. Instead of microballoons type, the composition of vol.% microoballoons varied as 40, 50, 60, 70, and 80% to investigate the influence of formulation. The results showed that at the same composition, microballoon with high crushing strength obtained higher compressive strength, but the density for microballoon with lower crush strength is lower. The increase in volume fraction for both types of microballoons resulted decreasing in density. With the use of low crushing strength microballoons, the compressive strength properties were decreasing with the higher volume fraction. But for microballoons with high crushing strength, there was no significant change in volume fraction variation.
Preparation and Characterization of Ni/C Particles as Filler in Bipolar Plate for Proton Exchange Membrane Fuel Cells M. Hamzah, Fadlilatul Taufany, Agung Purniawan, Ade Sholeh Hidayat, Lailatul Qadariyah International Journal on Engineering Applications, 2024 The graphite-Ni/C particles are prepared by Closed-Low Oxygen Pyrolysis Method (CLOPM), in which the graphite particles are coated by colloid of Ethylenediaminetetraacetic Acid (EDTA)-Ni (II) ligands that bound Ni. These graphite-Ni/C particles are dried, sized and compacted in a crucible and closed in low-oxygen state, then pyrolyzed at a temperature of 900oC. Ni/C particles as precursors have been investigated separately by SEM/EDS, HR-TEM, FTIR, PSA, XRF and Raman spectroscopy. Ni/C particles are 9.6 nm in size and consist of 40.7% of Ni, 52.4% of NiO, and 6.8% of C. The electrical properties of graphite-Ni/C powder have been measured in a compacted solid state. The electrical conductivity of graphite material coated with 10% Ni/C is 7.64 S/cm, which means an increase of 84% over the electrical conductivity of pure graphite, 4.15 S/cm, which has been achieved. These graphite-Ni/C particles will be used as a filler in bipolar plates for PEM fuel cells.
The Effect of Oligomeric Resins on Tire Traction of SBR/BR-Based Rubber Blends Indriasari Indriasari, Suppachai Sattayanurak, Riastuti Fidyaningsih, Ade Sholeh Hidayat, Mahendra Anggaravidya, Dewi Kusuma Arti, Akhmad Amry, Wahyu Tri Utami, Idvan Idvan, Herri Susanto, Sri Rahayu, Muhammad Dikdik Gumelar, Mohamad Soleh Iskandar, Lies Agustine Wisojodharmo Advances in Science and Technology, 2024 Resin is a compounding ingredient that can be used in tire treads to improve (wet) grip resistance. Increasing tan delta in the temperature range between 0°C and 20°C is important to improve (wet) grip resistance. To understand the behavior of resins and determine which resin is best suitable to improve traction in SBR/BR blends, the solubility of polyterpene and α-methyl styrene resin in SBR-BR blends is investigated. The method for measuring the solubility of resin in SBR/BR blends at a 70/30 weight ratio was developed. The solubility parameters (δ) were calculated based on the group contribution method, and the Δδ values between resins and rubbers were correlated with the weight increase of lightly crosslinked SBR/BR blends at different temperatures. A smaller Δδ means higher solubility of the resin in the rubber, which is confirmed by the high level of resin uptake in the rubber. Based on the research, it was found that molecular weight, polarity, and temperature, are factors, which influence the solubility of resins into the rubber. In addition, based on the DMA measurements, SBR/BR (Ni-cat) containing polyterpene shows a higher tan delta at 0 – 20°C compared to SBR/BR (Nd-cat) containing polyterpene. This fact indicates that a correct selection between the type of rubber and resin is important depending on the requirement needed.
Effect of Ribbed Smoked Sheet/Ethylene Propylene Diene Monomer Ratio on Mechanical Properties of Compounds for Pneumatic Fender Applications Riastuti Fidyaningsih, Saddam Husin, Herri Susanto, Idvan Idvan, Indriasari Indriasari, Ade Sholeh Hidayat, Mahendra Anggaravidya, Dewi Kusuma Arti, Wahyu Tri Utami, Galih Taqwatomo, Lies Agustine Wisojodharmo, Akhmad Amry, Dita Adi Saputra, Muhammad Dikdik Gumelar, Mohamad Soleh Iskandar Advances in Science and Technology, 2024 One type of technical rubber that is currently imported is a pneumatic fender, which mostly only uses synthetic rubber as raw material. Whereas natural rubber has superior mechanical properties that are better than synthetic rubber. This research will combine natural rubber (RSS) with EPDM synthetic rubber by varying the RSS/EPDM mass ratio. This study aims to determine the effect of the mass ratio of RSS/EPDM on the quality of the mechanical properties of pneumatic fender compounds. The rubber compound is made with a ratio of RSS/EPDM: 100/0, 90/10, 80/20, 70/30, and 0/100. The mechanical testing was carried out under normal and aging conditions. The test results showed that the mass ratio of RSS/EPDM rubber affected the mechanical properties of the resulting rubber compound. The rubber compound formula containing EPDM 10 to 30 phr is suitable for pneumatic fender applications due to better properties and resistance after aging, particularly compression set.
Comparative Analysis of NR/EPDM Ratio and Carbon Black Selection on Mechanical Properties of Vulcanized Pneumatic Fenders Mahendra Anggaravidya, Dita Adi Saputra, Muhammad Dikdik Gumelar, Galih Taqwatomo, Saddam Husin, Dewi Kusuma Arti, Mohamad Soleh Iskandar, Ade Sholeh Hidayat, Riastuti Fidyaningsih, Akhmad Amry Evergreen, 2023 In this research, natural rubber RSS1 was formulated with synthetic rubber EPDM and various types of carbon black filler for marine rubber fender products. This study aims to determine the effect of the NR/EPDM ratio and type of carbon black filler on the mechanical properties of rubber compounds. Mechanical properties testing followed the referenced ISO 17357-1:2014. The optimum rubber compound formulation was found in a sample with NR/EPDM ratio of 100/0 and carbon black N220 filler which has superior mechanical properties.
