Preparations of spherical polymeric particles from Tanzanian cashew nut shell liquid by suspension polymerization
Spherical Polymeric Particles (SPP) have been prepared from Tanzanian Cashew Nut Shell Liquid (CNSL) by suspension polymerization technique involving either step-growth or chain- growth polymerization mechanisms. The sizes of the SPP, which ranged from 0.1 to 2.0 mm were strongly influenced by the amounts of stabilizers in polymerization recipes used. The particles showed variable surface areas, indicative of the presence of pores in some of the preparations and the highest surface area recorded was about 260 m2g-1. The particles were found to exhibit Langmuir-type adsorption isotherms with saturation capacity of about 9.0 and 44.2 mg/g for Na+ and Ca2+, respectively. Step-growth polymerization produced SPP with relatively smaller surface areas and lower adsorption capacities of sodium and calcium ions compared to the particles produced through the chain-growth mechanism. Other particle characteristics depended strongly on the recipe employed and the surface OH functional groups apparently determine the potential applications of the SPP.
Tanzania Journal of Science Vol. 30 (2) 2004: pp. 1-10