Amphiphilic copolymeric stabilizer for the formation of polycaprolactone particles

Abstract

Amphiphilic copolymer poly(n-octadecyl methacrylate-co-2-hydroxyethyl methacrylate) (POHMA) of different molecular weights (MWs) were synthesized by radical copolymerization. The obtained copolymers were then assessed as stabilizer in the preparation of stable and uniform polycaprolactone (PCL) particles with smooth surfaces using the solvent evaporation method. To understand the efficiency of POHMA, the effect of different reaction parameters such as concentration of PCL and POHMA, MWs of POHMA, stirring speed as well as reaction time in the formation of PCL particles were investigated. Well-dispersed with spherical shape PCL particles have been observed at the lower concentration as compared to the higher concentration of stabilizer POHMA, while the best stabilizing effects were optimized with the PCL:POHMA ratio. With the increase in MWs the size of the PCL particles decreases from 50.35 to 19.82 µm and the uniformity decreases from 1.11 to 1.08. The reaction time and stirring speed also played a crucial role in the formation of stable PCL particles which can be observed by scanning electron microscope analysis.