Helical Polymer Particles Derived from Aromatic Acetylenics and Prepared by Suspension Polymerization

Abstract

Polymeric particles are constructed by aromatic acetylene derivatives through suspension polymerization approach. Phenylacetylene and 1-naphthylacetylene are used as monomers to conduct suspension polymerization in aqueous media at room temperature by using (nbd) Rh + B -(C 6 H 5 ) 4 as catalyst and polyvinylpyrrolidone (PVP) as stabilizer. The suspension polymerizations provide polymeric particles in high yield (>80%). Scanning electron microscopic images demonstrate that the particles assumed spherical morphology. The key factors infl uencing the formation of particles are systemically investigated. Under the optimized conditions, i.e., stirring speed being 500 rpm and with PVP as stabilizer in aqueous media, the resulting polyphenylacetylene particles exhibit satisfactory regularity in spherical morphology. Fourier-transform infrared and 1 H NMR spectra confi rm the occurrence of polymerization, while UV-vis absorption spectra demonstrate the helical structures of the polymer chains constructing the particles. The polymer chains form high cis contents (>87%) according to Raman spectra. Thermogravimetric analysis shows the high thermostability of the particles. a majority of the polymeric particles created so far were derived from vinyl polymers. For acetylenic polymers, in particular aromatic acetylenic polymers, it is still a big challenge to prepare their particles.As far as acetylenic polymer-based particles are concerned, the most intriguing feature lies in the polymer chains possessing conjugated structures, largely different from the vinyl polymer counterparts. Just like other conjugated polymers, for instance, polyfl uorenes, [ 13 ] polypyrroles, [ 14 ] polycarbazoles, [ 15 ] polythiophenes, [ 16 ] and polyanilines, [ 17 ] acetylenic-based polymer particles have wide potential applications in such signifi cant areas like sensors, [18][19][20] probes, [ 21 ] bio-imaging agents, [ 22 ] and lightemitting materials. [ 23,24 ] As a typical category of conjugated polymers, substituted polyacetylenes [25][26][27][28][29][30][31][32][33][34] are particularly expected to fi nd signifi cant practical applications in diverse areas ranging from materials science [ 35 ] to medical and biological fi elds. [ 36 ] Also remarkably,

Effects of polymerization conditions on particle size distribution in styrene‐graphite suspension polymerization process

“…Moreover, polymer beads with distinct average size should be able to obtain from batch to batch using the same reactor and with minimal process adaptation. Several experimental studies have been published on the effects of the above operational parameters on the PSD of polymer beads in suspension polymerization . Moreover, predictions of the PSD and the dynamic evolution of the particle formation process by simulation methods have also been reported .…”