Modifying Sodium Bicarbonate for Foaming Polymers

Sodium bicarbonate was modified with citric acid by solution coating method, and used to increase the foaming temperature and narrow the range of decomposition temperature. The thermodynamic parameters of sodium bicarbonate and modified sodium bicarbonate were studied by DSC and TG. After the modification, the initial decomposition temperature of sodium bicarbonate raised from 112.6 o C to 146.9 o C, endothermic peak temperature from 150.5 o C to 165.9 o C, the range of decomposition temperature narrows from 56.2 o C to 31.5 o C. After modification, sodium bicarbonate shows faster rate of decomposition.