"Thermal-oxidative aging behavior of latex sponge with different natural rubber latex content"

Abstract

Two kinds of latex sponge (80 NR and 0 NR) with different natural latex contents were exposed to 100 ℃ by accelerated hot air aging method. Their thermal-oxidative aging behavior was investigated by using yellowness index, whiteness index, crosslinking density and indentation hardness, and the hot air aging rule of the materials was discussed. The results showed that the yellowness index of 80 NR was always higher than that of 0 NR, while the whiteness index was always lower than the latter. The crosslinking density of 80 NR was always bigger than that of 0 NR, so the latex sponge of 80 NR was more prone to molecular chain breakage and crosslinking reaction. The indentation hardness of 80 NR was affected obviously by aging time, and would increase sharply in a short time. The indentation hardness of 0 NR was linearly correlated with aging time and had a small increase. The aging resistance of 0 NR was better than that of 80 NR.

Keywords

• latex sponge
• thermal-oxidative aging
• natural rubber latex
• yellowness index
• whiteness index
• crosslinking density
• indentation hardness