Production of oil-containing polyterephthalamide microcapsules by interfacial polymerization. An experimental investigation of the effect of process variables on the microcapsule size distribution.
Oil-containing polyterephthalamide microcapsules were prepared by the interfacial polymerization technique. The inner phase of the microcapsules consisted of a mixture of an organic solvent, toluene, and a commercial oil, santosol. Microcapsules with mean Sauter diameters in the range 0.5-20 microns were prepared by varying the rate of agitation (2000-7000 rpm) and the concentration of a poly(vinyl alcohol) stabilizer (0.1-1.0 wt% w/v), in the presence of several ionic and non-ionic cosurfactants. High agitation rates resulted in a significant reduction of the mean size of the oil droplets, although a slight increase in the breadth of the droplet size distribution was observed. High concentrations of PVA also resulted in a decrease of the microcapsule size, although the effect of stabilizer concentration was generally less important than that of the agitation speed. Finally, the effect of various ionic and non-ionic cosurfactants on the microcapsule size distribution was investigated. It was found that the addition of a cosurfactant significantly reduced the mean droplet size of the initial emulsion, leading to the formation of microcapsules in the submicron range.
Alexandridou
S
S
Department of Chemical Engineering, Aristotle University of Thessaloniki, Greece.
Kiparissides
C
C
D002214:Capsules; D055598:Chemical Phenomena; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D002627:Chemistry, Physical; D004339:Drug Compounding; D004355:Drug Stability; D004655:Emulsions; D009821:Oils / Q000737:chemistry*; D010316:Particle Size; D010797:Phthalimides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry; D014783:Viscosity
D002214:Capsules; D004655:Emulsions; D009821:Oils; D010797:Phthalimides; D011108:Polymers; D013501:Surface-Active Agents; D011142:Polyvinyl Alcohol