Micron-sized polymeric particles from cashew nut shell liquid: Influence of reaction parameters on particle size

Cashew nut shell liquid based polymer latexes of narrow size distribution and average particle sizes ranging from 0.1 to 0.4 µm were prepared by base catalysed emulsion polycondensation of cashew nut shell liquid of 820 centipoises viscosity with formaldehyde. The influence of emulsifier concentration, sodium hydroxide concentration and stirring rate on average particle size and size distribution was studied for the given geometry of the reactor and the stirrer. It was found that these variables have a significant effect on the particle size and particle size distribution and that average particles size can be predicted and controlled by the choice of these experimental variables. Interrelationships between these variables appear to be complex, however the apparent monotonic variation of average particle size with emulsifier concentration makes emulsifier concentration the most convenient parameter of controlling particle size. The influence of the type of mixers and various reaction kettle designs on the polymer particles' sizes should be studied.