Synthesis of Narrow or Monodisperse Core-shell Microspheres by Distillation-Precipitation Polymerization
writer：Donglai, Qi, Feng Bai, Xinlin Yang*, Wenqiang Huang*
keywords：Poly(ethyleneglycol dimethacrylate); Monodisperse; Polymer microspheres; Distillation–precipitation polymerization
source：期刊
specific source：Eur. Polym. J., 41 (10), 2320-2328 (2005). DOI: 10.1016/j.europolymj.2005.04.034
Issue time：2005年
Highly crosslinked narrow or monodisperse poly(ethyleneglycol dimethacryltae) (polyEGDMA) microspheres were prepared by distillation–precipitation polymerization in neat acetonitrile with 2,20-azobis(2-methyl propinitrile) (AIBN) as an initiator. The polymer microspheres with clean surfaces due to the absence of any added stabilizer in the reaction system were formed simultaneously through a precipitation manner during the distillation of acetonitrile off the reaction system. The effects of the solvent, initiator concentration, monomer concentration and comonomer (divinylbenzene, DVB) fraction on the formation of the microspheres were investigated. Narrow- or monodisperse particles with spherical shape and smooth surface were obtained with diameters between 1.18 and 2.50 lm with monomer loading lower than 3.13 vol%. The surfaces of the microspheres became rougher, some elliptic particles and doublet or triplet appeared with the increase of monomer concentration (as high as 3.75 vol%). The yield of polymer microspheres was increased from 31% to 75% with the increase of EGDMA fraction from 0 to 100% when EGDMA was copolymerized with DVB. The resulting polymer microspheres were characterized with scanning electron microscope (SEM) and Fourier transform-IR spectra.