Fully crosslinked poly(styrene‐co‐divinylbenzene) microspheres by precipitation polymerization and their superior thermal properties

Abstract

Fully crosslinked, stable poly(styrene‐co‐divinylbenzene) microspheres, which are composed of various concentrations of divilylbenzene from 5 to 75 mol % based on styrene monomer, were prepared without a significant particle coagulation by the precipitation polymerization. The number‐average particle diameter ranged from 3.5 to 2.8 μm and decreased with an increasing concentration of divinylbenzene in monomer. In addition, the coefficient of variation of the microspheres was slightly reduced with the increasing concentration of divinylbenzene. The circularity and the measured specific surface area indicated that lesser particles are coagulated because of the improved stability of individual particles at a high divinylbenzene concentration and that the resulting particles have a smooth surface without micropores. The glass‐transition temperature was not observed for all microspheres formed from the range of divinylbenzene concentrations. In addition, the onset of the thermal‐degradation temperature was increased from 339.8 to 376.9 °C upon higher contents of divinylbenzene. On the basis of the DSC and thermogravimetric data, the polymer microspheres prepared by the precipitation polymerization possessed a fully crosslinked structure and highly enhanced thermal stability. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 835–845, 2004

Synthesis of poly(acrylamide‐co‐divinylbenzene) microspheres by precipitation polymerization

“…23 In addition, mechanistic studies to elucidate the formation of stable microspheres in the absence of any stabilizer have been reported 24,25 in which the absorption of oligomeric species onto the nuclei and the high degree of crosslinking are the primary reasons for the formation and stable growth of the microspheres.…”

“…28 In our previous studies, poly(St-co-DVB) and poly (MMA-co-DVB) microspheres containing various concentrations of divinylbenzene (DVB), from 5 to 75 mol %, were synthesized by precipitation polymerization, and their unexpected thermal properties, superior to those of crosslinked polymers prepared by emulsion and suspension polymerization, were found to be due to a fully crosslinked microstructure. 22,23 In this study, poly(acrylamide-co-divinylbenzene) [poly(AAm-co-DVB)] microspheres were prepared by precipitation polymerization, and the effects of DVB on the polymerization characteristics and size/uniformity of the microspheres were investigated.…”

Thermal evolution of structure and photocatalytic activity in polymer microsphere templated TiO2 microbowls

“…3) exhibits a 2.7 wt% loss in the temperature range of 30-250 • C due to the evaporation of water and other volatile organics. TiO 2 reveals a negligible gravimetric loss within 30-800 • C, while pure/uncoated polystyrene undergoes almost 100 wt% loss within 300-500 • C due to decomposition/degradation [21][22][23]. Thus, TGA data in Fig.…”

“…6 can be elucidated by using the structural properties of the polymer-templated TiO 2 microstructures shown in Scheme 3. The crosslinked polystyrene systems have typical glass transition temperatures (T g ) within 100-150 • C, above which the solid polymer tends to switch to a mobile molten/glassy state [23]. As can be seen from the specific surface area (SSA) results shown in Scheme 3, PsTi-200 sample has a moderately high SSA (86 m 2 /g) suggesting that the mobilized PS-co-DVB microsphere template starts to segregate on the very top surface, only partially covering/blocking the amorphous TiO 2 /TiO x coating on the microsphere system.…”

Effect of co-initiator on the size distribution of the stable poly(styrene-co-divinylbenzene) microspheres in acetone/water mixture

“…14 Up today, the synthesis of highly crosslinked polymers using various self-crosslinkable monomers have widely been studied; poly(divinylbenzene) [P(DVB)], 15,16 poly(methacrylic acid-co-polyethylene oxide methyl ether methacrylate), 17 poly(methacrylate-co-DVB), 18 poly(chloromethyl styrene-co-DVB), 19 poly(DVB-co-maleic anhydride), 20 poly(methyl methacrylate-co-DVB), 8,21,22 poly(styrene-co-DVB) [P(St-co-DVB), 23 poly(acrylamide-co-DVB) 24 and poly(glycidyl methacrylate-co-DVB). 25,26 In addition, mechanistic studies to elucidate the formation of stable microspheres in the absence of any stabilizer have been reported.…”