Abstract:

Brominated natural rubber(BNR) with different bromine content was prepared in the latex phase. Fourier transform infrared spectroscopy(FTIR) and 1H NMR spectroscopy were applied to investigate the microstructures of BNR from latex. Scanning electron microscope(SEM) was adopted to observe the morphology of BNR products, and the solubility and nitrogen content of BNR products with different bromine content were studied. FTIR analysis shows that bromination substitution and addition occur during the bromination of NR latex. 1H NMR analysis confirms the addition of C=C group and the bromination substitution of methylene and methyl groups. Bromine content has an obvious effect on the morphology of BNR products. With the increment of bromine content, BNR product is getting hardened and crisp, easier to be powdery and the dimension of particles gradually decreases. The solubility sequence of BNR product in different solvents is as follows:benzene, carbon tetrachloride＜toluene, xylene＜tetrahydrofuran＜chloroform＜cyclohexanone; and the solubility of BNR in the same solvent increases with the increment of bromine content. Nitrogen content of BNR products decreases with the increment of bromine content. Nitrogen content decreases to 0.10% when bromine content is 42%.

Key words: brominated natural rubber, natural rubber latex, microstructure, property