Preparation and Characterization of Sulfonated Polystyrene Latexes

Abstract

ABSTRrZCT ?'he purpose of the \vork was the preparation of aqucous suspensions of model spherical particles stabilized by ionizable groups covalently bound to the surface. Starting material >\Ins a 80/20 styrene/divinylbenzene latex. 'The latex had an average particle diameter of 500 A a s determined in the electron microscope. The copolymer mas sulfonated in dichloroethane with a 3/1 SOx/triethylphosphate complex in a concurrent-flow fast-reaction apparatus and was purified by dialysis and ion exchange.'Three main fractions with neutralization eq~~ivalents, N, of 0.9, 1.8, and 2.7 tneq g-1 \\-ere prepared. Elemental analysis revealed that the varying N, in these fractions resulted fro111 the absorption of Ca2+ and R/IgZ+ ions which were tightly bound to the inner-lying sulfonic groups of the particles. Treatment with strong acid followed by ion exchange eliminated the bivalent ions and increased N,, but the titration pattern was markedly changed after such treatment. Sulfonation caused both the partial specihc volume and the refractive index increment to decrease. Electron micrographs showed that the latex particles were only slightly polydisperse and that there was little change in size and shape after sulfonation. Lightscattering measurements established the absence of aggregates in the sulfonated latex. Particle sizes, determined from the intrinsic viscosities, indicated some swelling of the particles in 1 il/I aqueous NaCI. The extent to which the sulfonated latex satisfies the criteria required of a model colloid to be used for a study of electroviscous behavior is discussed.

Synthesis and Characterization of Cross-linked Sulfonated Polystyrene Nanoparticles

“…Various methods for synthesizing cation-exchange resins have been reported in the literature and most involve sulfonation of polymerized particles . The most commonly used method is suspension polymerization, − where water is used as suspending medium to disperse droplets of monomers.…”

“…Various methods for synthesizing cation-exchange resins have been reported in the literature and most involve sulfonation of polymerized particles. 16 The most commonly used method is suspension polymerization, [17][18][19] where water is used as suspending medium to disperse droplets of monomers. The initiator is soluble in the monomer, and the reaction progresses as bulk polymerization within the microreactors formed by monomer droplets.…”

Preparation and surface modification of poly(vinylbenzyl chloride) latices

“…In general, one can control the latex surface charge either by varying the latex preparative r e~i p e ,~-~ or by modifying the final latex surface. [8][9][10] The modification of the final latex surface is attractive for producing a series of latices with the same particle size but different surface charge. However, depending on the type of monomer used to prepare the latex particles, the surface modification experiment can be very cumbersome.…”