ACROLEIN POLYMERIZATION: MONODISPERSE, HOMO, AND HYBRIDO MICROSPHERES, SYNTHESIS, MECHANISM, AND REACTIONS.

In the reported experiments, monodisperse polyacrolein (PA) microspheres were obtained by a single step process via two mechanisms: (a) aqueous polymerization of acrolein under alkaline conditions and (b) aqueous radical polymerization of acrolein by irradiation with a cobalt source. The diameter of the former microspheres can be varied from 0. 04 up to 8 mu m. The monodispersity of the system is also discussed. The diameter of the latter microspheres can be varied up to 0. 2 mu m. Hybrido PA microspheres were formed by grafting PA microspheres of average diameter of 0. 1 mu m obtained by irradiation onto the surface of PA microspheres produced by the alkaline mechanism. The aldehyde content of the microspheres prepared by irradiation is much higher than those of the microspheres formed under alkaline conditions. The aldehyde groups were used for the covalent bindings of ligands containing primary amino groups, such as proteins and drugs, in a single step under physiological pH.