Preparation and Characterization of TiO₂-Coated Hollow Glass Beads for Functionalization of Deproteinized Natural Rubber Latex via UVA-Activated Photocatalytic Degradation

The photochemical degradation of natural rubber (NR) is a prevalent method used to modify its inherent properties. Natural rubber, predominantly derived from the Hevea Brasiliensis tree, exhibits an exceptionally high molecular weight (MW), often reaching a million daltons (Da). This high MW restricts its solubility in various solvents and its reactivity with polar compounds, thereby constraining its versatile applications. In our previous work, we employed TiO₂ in its powdered form as a photocatalyst for the functionalization of NR latex. However, the post-process separation and reuse of this powder present substantial challenges. In this present study, we aimed to functionalize deproteinized NR (DPNR) latex. We systematically reduced its MW via photochemical degradation under UVA irradiation facilitated by H₂O₂. To enhance the efficiency of the degradation process, we introduced TiO₂-coated hollow glass beads (TiO₂-HGBs) as photocatalysts. This approach offers the advantage of easy collection and repeated reuse. The modified DPNR showed a reduction in its number-average MW from 9.48 × 10⁵ to 0.28 × 10⁵ Da and incorporated functional groups, including hydroxyl, carbonyl, and epoxide. Remarkably, the TiO₂-HGBs maintained their performance over seven cycles of reuse. Due to their superior efficacy, TiO₂-HGBs stand out as promising photocatalysts for the advanced functionalization of NR across various practical applications.