Preparation And Property Study Of Nano-TiO₂/natural Rubber Compound Materials

PDDA modified nano-TiO2 (titanium dioxide) solution was prepared by tetrabutyl titanate through sol-gel method. And with the TiO2 solution and NR(natural rubber) latex, it was prepared of TiO2/NR compound latex by the latex blending and self-assembly method, and got the unvulcanized and vulcanized TiO2/NR nanocomposites by the process of prevulcanization and drying. Analysed the crystalloid type of TiO2 powder by XRD, and discussed the self-assembly mechanism by TEM, particle size and zeta potential. Observed the nanocomposites' micro-morphology by SEM. Tested the saving stability of the composite latex, mechanical, dynamic mechanical and thermal degradation properties. Tested the photocatalytic properties include the antimicrobial activity and efficacy to escherichia coli and mould, and the ultraviolet degradation to methylene blue.The crystalloid type of TiO2 powder is anatase. The size of PDDA modified TiO2 is less than 20nm, and zeta potentials is+28.1mV. The size of unmodified TiO2 particle bigger than the modified. The reason is mainly about the unmodified TiO2 particles which have high specific surface area congregate easily, but the modified TiO2 particles have a lower surface energy, and it can reduce the degree of aggregation. Latex blending and self-assembly is a process of electrostatic adsorption between anion and cation. This process have two stages:First stage, cationic polyelectrolytes PDDA adsorb the fresh nano-TiO2 particles which taking negative charge after gel, and formed a core-shell structure TiO2 particle, Second stage is the latex blending process. The anionic NR latex particle adsorb the cationic core-shell TiO2, and prepare the TiO2/NR compound latex. SEM images show TiO2 uniformly disperse in NR matrix. The TiO2/NR nanocomposites can resistance more than 90% escherichia coli. And the test of mould resistance also shows the material's resistance level has reached grade 0, it is effectual to mould resistance. TiO2/NR nanocomposites have a certain effect to degrade methylene blue in ultraviolet light. And there is no marked difference of mechanics properties between the nanocomposites and NR.