The Mechanical Properties of Vulcanized Deproteinized Natural Rubber

Properties of deproteinized natural rubber (DPNR) were investigated in order to apply the DPNR latex as non-allergy vulcanized rubber thin film products. Removal of proteins from natural rubber was made by incubation of high ammonium natural rubber latex (HA-NR) with urea 0.1 wt%, 1 hour in the presence of surfactant at room temperature (DPNR). The nitrogen content of the DPNR was reduced to 0.05 wt%, which was lower than 0.45 wt% of HA-NR under the test condition. The reduction of protein content can be confirmed by observation a chemical structure through FT-IR technique. It is suggesting that the urea treatment is an effective method to remove protein from rubber latex. Then, physical properties of the DPNR latex were investigated. Amount of water soluble protein was observed through modified lowry method and it was found that water soluble protein content after incubation HA-NR with urea was reduced to 15 g/g (DPNR) from 4,245 g/g (HA-NR). It was found that VFA number of DPNR was lower than that of HA-NR due to lower amount of protein presence in rubber latex. The particle size and charge of rubber latex was examined by dynamic light scattering and zeta potential to compare between un-vulcanized latex and vulcanized latex. The mechanical properties were then observed when we applied the DPNR latex to vulcanized rubber glove.