As a result of industrialization and environmental pollution, increasing importance is being given to eco-friendly materials and technology. In particular, eco-friendly biocomposites using polylactic acid (PLA) have attracted great interest. In this work, fiber-reinforced composites were investigated in order to enhance the mechanical properties and improve the economic efficiency of PLA. Specifically, composite materials using natural fibers, such as kenaf were actively studied. In the utilization of natural fibers, such as kenaf, the treatment method for increasing the bonding force between the fiber and the matrix is very important. In this study, the surface of kenaf was treated using an acetylation technique, and the PLA composite material was prepared using surface-treated kenaf. Changes in fiber properties were observed with acetylation treatment time. The mechanical properties, thermal stability, and water absorption resistance of the acetylated kenaf and PLA composites prepared for each condition were evaluated. Finally, was concluded that acetylation treatment is effective for improving the performance of PLA/kenaf composites. This behavior was found to relate to the surface cleaning of acetylated kanaf, in addition to the efficient modification of the hydrophilic characteristics of kenaf.

The increasing prevalence of atopic dermatitis (AD) is associated with variations in indoor environments. In Korea, many inner walls of homes are covered with wallpaper: such walls emit indoor air pollutants, including volatile organic compounds (VOCs) and formaldehyde. This randomized, double-blind study investigated the effects of wallpaper on indoor air quality and AD. Thirty-one children (aged three to eight years) with moderate AD were assigned to environmentally-friendly (EF) and polyvinyl chloride (PVC) wallpaper groups. Indoor air concentrations of VOCs, natural VOCs (NVOCs), formaldehyde, and total suspended bacteria were measured before and two (W₂) and eight weeks (W₈) after wallpapering. Scoring Atopic Dermatitis (SCORAD) evaluations and blood tests were performed during the same period. The EF wallpaper and PVC wallpaper groups showed similar trends in the changes in total VOCs (TVOC) and formaldehyde content in the indoor air. However, the EF wallpaper group showed more improvement on the SCORAD at W₂ and W₈ than the PVC wallpaper group. The SCORAD index was positively correlated with several indoor air pollutants. Further, the SCORAD index and NVOC % were negatively correlated. Improved SCORAD index and effects of wallpapering on indoor air quality improvements occurred within a short period of time in both groups. We believe that NVOCs in indoor air after EF wallpapering have a beneficial effect on health.

Total volatile organic compounds (TVOCs) are widely used to assess indoor air quality (IAQ). However, because TVOCs combine diverse compounds into a single metric, they cannot distinguish individual emission sources or chemical characteristics. Indoor environments with natural materials such as wood may emit biogenic volatile organic compounds (BVOCs), elevating TVOC concentrations and limiting the interpretation of indoor air quality. This study evaluated TVOC concentrations and chemical composition before and after installing wooden interiors in 36 public facilities in South Korea, including daycare centers, nursing homes, and welfare facilities. Domestic wood species, including Chamaecyparis obtusa, Larix kaempferi, and Cryptomeria japonica, cover approximately 49% of the interior surfaces. Major regulated VOCs, including benzene and toluene, did not increase significantly after installing wooden interior materials. Mean TVOC concentrations increased from 244.2 ± 139 to 640.1 ± 542.3 μg/m³, accompanied by significant increases in several terpene-related BVOCs, including α-pinene, myrcene, and cymene, as well as an increase in the absolute concentration of unidentified VOCs. Elevated TVOC concentrations in wood-based indoor environments may reflect compositional changes rather than poorer indoor air quality. Therefore, TVOC concentrations should be interpreted alongside compound-specific analyses rather than relying solely on a single TVOC indicator.