We have developed a two-step method using preadsorbed ethylenediamine (EDA) to catalyze the reaction of (3-aminopropyl)dimethylethoxysilane (APDMES) on silica surfaces. The amount of adsorbed APDMES is nearly twice the amount obtained when the same reaction is performed without the preadsorbed EDA or when monoamines such as propylamine or triethylamine are used instead of EDA. In addition, the use of preadsorbed EDA leads to an increase in the number of chemisorbed APDMES with free aminopropyl groups extending from the surface. Preadsorbed monoamines such as triethylamine, pyridine, or propylamine do not alter the adsorbed amount or change the number of free amine groups extending from the surface because they are easily displaced from the surface by APDMES. Infrared spectroscopy is used to follow the surface reactions on silica powder, and contact angle measurements show that this method also works on glass slides.

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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.