This systematic literature review aims to study the thermal properties (TP) of poly(acrylic acid)-based hydrogels (PAA) by differential scanning calorimetry. The data sources were obtained from Google Scholar via Publish or Perish software from 2018 to 2020. The synthesis results show that most of the analysis of TP in PAA-based hydrogel consists of glass transition temperature ([ ]), melting temperature ([ ]), and enthalpy ([ ]). The subsequent thermal properties analysis is important for a new development and depth study in the future application.

The creative fashion industry produces several textile products that play an important role in the national economy. In various countries, this industry has continued to grow along with the strong flow of information technology and e-commerce. The development of textile products for fashion is very dynamic and competitive. Competition is not only about price, but also the quality of organic/synthetic materials, the comfort provided, and designs that change every 4–6 months. Recently, creative fashion not only relies on natural and synthetic polymer-made fibers but also biomass-based waste materials. Therefore, this study aims to manufacture textile products from biomass-based waste materials that can be applied to the creative fashion industry. Two types of raw materials from oil palm empty fruit bunches (EFB), namely, whole-empty fruit bunches (WEFB) and stalk-empty fruit bunches (SEFB), are used as an excellent innovation of rayon viscose fiber (RVF), a noncotton organic yarn capable of providing a solution to the 99% import of global cotton needs. This is expected to increase competitiveness, as well as the added value of palm oil products and their derivatives. The process of manufacturing DP chemically includes prehydrolysis, cooking, bleaching to dissolve the lignin and noncellulosic materials as well as isolation to purify POEFB fiber. Furthermore, DP testing is carried out to determine product quality and compare it with the national product standards. The results show that the alpha-cellulose content reaches >94% with variations in the active alkali of 18%, 20% and 24%. This implies that the WEFB and SEFB are used to fulfill the first requirements of the national standard (SNI 938:2017). The WEFB with an active alkali variation of 24% meets the SNI standard for rayon pulp with a value of S₁₀ = 3.07 and S₁₈ = 7.14%, while all variations of SEFB show opposite results. The use of active alkali at 24% had a brighter color than between 18% and 20%. Additionally, the fiber density of WEFB appears to be higher than that of SEFB. These results correlate positively with DP prepared using 24% alkali as the optimum treatment for all products, as well as the morphological observations performed with scanning electron microscopy (SEM), which shows that WEFB fixated fiber had a larger diameter than SEFB.

The performance of helmet prototypes fabricated from acrylonitrile butadiene styrene composites filled with oil palm empty fruit bunch fibers was evaluated. The fibers were produced using a milling procedure, while the composites were fabricated using a single-screw extrusion. The physical characteristics of the produced fibers, which are water content, size, and density, were investigated. In addition, the mechanical properties of the produced helmets, including shock absorption, yield stress, frequency, and head injury criterion (HIC), were examined. The impact strength of the produced helmets increases with the rise of filler content. In addition, the helmets were also able to withstand a considerable pressure such that the transmitted pressure was far under the maximum value acceptable by the human skull. The present work also found that HICs exhibited by the investigated helmet prototypes fulfill all the practical guidelines as permitted by the Indonesian government. In terms of novelty, such innovation can be considered the first invention in Indonesia since the endorsement of the use of motorcycle helmets.

The ballistic impact behavior of oil empty fruit bunch fiber reinforced bio-composites was studied. Epoxy and polyester resins were used as the main material and were evaluated as a matrix to determine their capability. The ballistic test was performed using a 9 mm handgun and a jacketed hollow point round. A model based on kinematics and dynamics was used to calculate the decrease in velocity of the projectile with a constant deceleration. The energy lost during the impact was calculated based on the theory of kinetic energy. The epoxy bio-composite was able to hold a projectile more successfully than the polyester bio-composite at a certain penetration depth. The curve of the decrease in velocity for both of the resins was exponentially distributed. An 18% epoxy bio-composite was able to more successfully stop the projectile at a penetrative depth of 2.14 mm and was able to absorb all the kinetic energy generated (408 J).

The present work aims to investigate mechanical and molecular characteristics of acrylonitrile butadiene styrene (ABS) composites filled with oil palm empty fruit bunches (OPEFB) microfibers. OPEFB microfibers were produced using mechanical milling. Composite granules were fabricated using single screw extruder. These composites were then used for fabricating helmet according to the Indonesian National Standard (SNI). Mechanical testing confirms that the helmet produced using this biocomposites are suitable to the SNI. Molecular interaction between matrix with OPEFB can be described using orbital hybridization theory. In general, this study has successfully investigated mechanical and molecular properties of the biocomposites.