Synthesis of Microcapsules by Ring-opening Metathesis Polymerization Using Water-in-Oil-in-Water Emulsions

The presentation of environmentally-friendly and thermally expandable microcapsule was attempted by ring-opening metathesis polymerization (ROMP) using water-in-oil-in-water (W/O/W) emulsions. Copolymerizations of 2-norbornene (NBE) with dicicropentadiene (DCP) were performed using a well-defined alkylidene ruthenium catalyst (PCy3)(2)(Cl)(2)Ru = CHPh. Particles with an average size of 10 similar to 40 mu m were obtained in high yield from the monomer feed (NBE: 5.9 mmol, DCP: 0.015 mmol) and the appropriate catalytic amount ((PCy3)(2)(Cl)(2)Ru=CHPh 10 x 10(-4) M, 5 mL (5 x 10(-7) mmol)) in the presence of ionic surfactant AOT under nitrogen atmosphere at 0 degrees C. The SEM image suggested that particles contained a small portion of multihollow structure. However, no thermal expansion of the particles could be observed.