Ramie (Boehmeria nivea) is one of the strongest natural cellulose fibers. Optimizing abundant resources ramie as a candidate materials used for reinforcing in polymeric composite material is a must to obtained high-performance natural fibers reinforced polymer especially for bulletproof panel or high-impact flexibility safer structures. Ramie woven was treated using common chemical solvents that were ethanol, methyl ethyl ketone, acetone, and silane as coupling agent. Composite panels were made by hand lay-up process with epoxy as a matrix. These prototype bulletproof panels were to be believed lighter in weight and much lower economic cost than conventional bulletproof panels made from ceramic plate, Kevlar/aramid composite, and steel-based material as a popular today in military standard antiballistic equipments. From the bullet testing result, it showed that panel could be able to resist the penetration of high-impact projectile for level II with some fractures phenomenon. Level IV ballistic testing showed that all prototype panel could not resist the high-impact velocity of the projectile yet. It was found that ramie Downloaded from fibers have sufficient breaking strength and toughness for level II bullet testing, although still needs improvements to optimize process parameters to meet a very high military standard and application KEY WORDS: Ramie woven composite, bulletproof panel, ballistic testing, NIJ standard.

The effects of alcohol, acetone, and methyl ethyl ketone solvent-based treatment on surface topography of ramie single fiber are investigated. In this study, the average of specific porous volume and specific surface area of ramie single fiber are determined to interpret the effects of the treatment quantitatively using Brunauer-Emmet-Teller surface area method. Fourier Transform Infrared Spectroscopy is applied directly to the fiber to detect the differences of molecular group function in the fiber surface. Qualitatively, scanning electron microscopy was also provided. The result shows that the solvent treatment could improve surface topography to gain matrix penetration when utilizing the fiber into polymeric composite material.

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Phenolic resin is the most common resin binder used in brake pad materials. Selection of the relative amount of phenolic resin is an important to maintain structurally intact with the other ingredients of brake pad composite. In this experimental study, the effects of phenolic resin as a binder in non-asbestos organic brake pad was investigated. The brake pad composite was made using a powder metallurgy technique. Four formulations with different volume fractions 10, 15, 20, and 25 were selected. Parameters applied were 47 MPa compaction pressure, 150 °C molding temperature, and 130 °C post curing temperature with 6 hours holding time. The properties of brake pad composite were examined density, porosity, hardness, thermal stability, and friction performance (refers to SNI 09-0143-1987). The results show the increase of phenolic resin content can decrease the density, porosity, thermal stability, friction coefficient, and volume wear rate by 1%, 16.79%, 2.39%, 42.5%, 24.16%, respectively. However, the hardness increases by 19.29 %. This investigation also recommends not to select 10 and 15 volume fraction of phenolic resin due to lower resistance to mechanical stresses although the thermal stability is better than the other studied composites.

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