PREPARATION AND CHARACTERIZATION OF BALLISTIC RESISTANT FIBER BASED ON NANOCRYSTALLINE CELLULOSE AS RAW MATERIAL FOR BULLETPROOF VEST FABRICATION

• Main Author: S T M T, Steven
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55218
• Institution: Institut Teknologi Bandung

Bulletproof vest is a part of critical military or protective device which is generally used to protect military personels, state leaders, or civilians from the threat of ballistic attack. The ability of bulletproof vests to protect the users is greatly affected by the materials that make up the bulletproof vest. Ballistic resistant fiber is the critical materials that play an important role in preventing the ballistic or sharp object from penetrating the bulletproof vest. Materials classified as ballistic resistant fiber is required to have high strength and stiffness, low density, good resistance to chemicals. Kevlar and ultra-high molecular weight polyethylene (UHMWPE) fibers are the most widely used ballistic resistant fibers in the fabrication of bullet-proof vests. However, utilization of these materials in Indonesia is seen to be difficult since its production involves a variety of sophisticated equipment and chemicals that are not available domestically in Indonesia. Nanocrystalline cellulose or NCC is a nano-sized crystalline part of cellulose obtained through the hydrolysis process of alpha cellulose. NCC commonly isolated using an acid hydrolysis process that allows removal of amorphous part of cellulose and leaving more chemical-resistant crystalline region intact. NCC is characterized by the degree of crystallinity ranging from 80 – 99% and a size of less than 300 nm. NCC is also known to have theoretical strength of up to 10 GPa, theoretical modulus of elasticity of 150 GPa, inability to melt, and excellent chemical resistance. These properties caused NCC is seen to have the potential to be developed into an alternative ballistic resistant fiber. In this research, the preparation and characterization of ballistic resistant fiber based on nanocrystalline cellulose was studied. The result of this study is expected to give a contribution to the development of domestic production of ballistic resistant fiber in Indonesia, which later could be developed into a bulletproof vest. This research divided into seven stages, that is the determination of the constituent component, physical properties and mechanical properties of Cladophora sp. algae cellulose; extraction process, and characterization of nanocrystalline cellulose and Cladophora sp. algae cellulose; the fabrication, and characterization of Cladophora sp. algae nanocrystalline cellulose-based ballistic resistant fiber; preparation and characterization of natural rubber matrix; fabrication, and evaluation of NCC/PVA-natural rubber hybrid filament material; and ballistic simulation of NCC/PVA-natural rubber hybrid filament material. Characterization on Cladophora sp. algae showed that it consists of cellulose, hemicellulose, lignin, extractive matter, lipid, protein, and ash. Tensile strength and modulus of elasticity of untreated Cladophora sp. algae are lower than kevlar and UHMWPE fiber. The extraction process of cellulose from Cladophora sp. algae conducted through alkalization, acid treatment, and bleaching. The highest cellulose purity is 96.27% obtained through the alkali treatment process using 17.5% NaOH solution, 1M sulfuric acid treatment, and H2O2 bleaching process. Isolation of NCC conducted through a sulfuric acid hydrolysis process. The evaluation showed that samples qualified to be categorized as nanocrystalline cellulose were 2M15J, 3M15J, 5M5J, 5M10J, 5M15J. The preparation of NCC/PVA filaments is conducted through the wet-spinning method. The highest tensile strength and modulus of elasticity obtained of NCC/PVA filament are 2M15J, 3M15J, and 5M5J filaments with 20% NCC loading. Improvement of tensile properties of NCC/PVA fiber is conducted through the dope stretching process. Sample coded as 2M15J 20 150 fiber showed a comparable tensile strength and modulus of elasticity to the commercial ballistic resistant fibers after 150 % dope stretching treatment. The highest tensile strength and modulus of elasticity obtained from NCC/PVA fiber is 3,085 GPa dan 63,20 GPa. The hybridization of NCC/PVA-natural rubber is considered due to the limited ability of NCC/PVA fiber to be woven into high-density fabrics. Natural rubber is used as binding material. Natural rubber with an accelerator concentration of 0.4 phr and carbon black content of 30 phr was found to be most suitable to be used in hybrid material preparation. The highest tensile strength and modulus of elasticity obtained from the hybrid material is 145.89 MPa and 12,08 GPa respectively, that reached in 44.63% volume fraction. The ballistic simulation shows that the minimum thickness of the hybrid material required to withstand a bullet with a speed of 436 m/s is 15 mm with a total weight of 4391,72 gr.