The Preparation of Hydroxyl-Terminated Deproteinized Natural Rubber Latex by Photochemical Reaction Utilizing Nanometric TiO2 Depositing on Quartz Substrate as a Photocatalyst

Abstract

Hydroxyl-terminated natural rubber (HTNR) is a product of interest for making natural rubber (NR) easy and versatile for use in a wide range of applications. Photochemical degradation using a TiO2 film that has been deposited on a glass substrate is one of the fascinating methods of producing HTNR. Nevertheless, light energy is wasted during the photodegradation process because a glass substrate has a cutoff for ultraviolet light. To enhance the effectiveness of the process, a quartz substrate was placed on the TiO2 film-coated substrate for photochemical breakdown. X-ray diffraction (XRD) spectroscopy and atomic force microscopy (AFM) were applied to investigate the TiO2 deposited on glass and quartz substrates. In addition, the influence of several factors, such as rubber and surfactant concentrations, on the reaction was investigated. After the reaction, the properties of the rubber products, including intrinsic viscosity, molecular weight, and microstructure, were determined. A unique diffraction peak for the anatase (101) phase could be observed in the TiO2 film deposited on the quartz substrate, resulting in photochemical activity and photocatalytic efficiency significantly higher than those of the substrate made of glass. In the scenario of deproteinized NR (DPNR) latex containing 10% DRC, 20% w/w H2O2, and TiO2 film coated on a quartz substrate, the HTNR could be manufactured effectively.

Study on Degradation of Natural Rubber Latex Using Hydrogen Peroxide and Sodium Nitrite in the Presence of Formic Acid

“…LNR containing hydroxyl and carbonyl end groups was observed, resulting from chain breaking. Sillapasuwan et al [ 5 ] synthesized the deproteinized LNR with hydroxyl end groups by the photochemical reaction. This reaction was carried out through photocatalytic decomposition of H 2 O 2 when exposed to UV light, with or without a TiO 2 film mounted on the quartz substrate.…”

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

“…Fine TiO 2 powder is advantageous for promoting the reaction; however, separating the powder after use is difficult. Our group previously employed TiO 2 -coated glass and quartz substrates as containers for NR latex to manufacture telechelic liquid NR [32,33]. The reaction was conducted for 5 h in the presence of H 2 O 2 under UV irradiation.…”