Emulsion Polymerization of Styrene Using Conventional, Polymerizable, and Polymeric Surfactants. A Comparative Study

Abstract

The emulsion polymerization of styrene is investigated, employing analogous conventional, polymerizable, and polymeric cationic surfactants (“polysoaps”). The polymerization and the properties of the latexes depend sensitively on the emulsifier and on the charge of the initiator. There is no visible correlation between the properties of the final latexes and the properties of the emulsifiers such as surface activity, solubilization capacity, or the ability to stabilize the initial monomer emulsion. When a cationic initiator is employed, all emulsifiers lead to stable monodisperse latexes, except for polysoaps with low hydrophobe content. The polymerizable, as well as the polymeric emulsifiers, yield latex solutions with very high surface tensions, different from the use of the standard surfactant. In contrast, the use of an anionic initiator can pose difficulties. The polymerizable emulsifier is efficiently fixed to the latex by copolymerization, being mostly consumed in the early stage of the reaction. Also, small amounts of the polysoaps are grafted onto the latexes during the reaction.

Reactive surfactants in heterophase polymerization

“…Cochin et al [60] carried out a comparative study using polymerizable and non-polymerizable cationic surfactants in the emulsion polymerization of styrene. It was found that when a cationic initiator was used, the latexes prepared with the polymerizable analogue presented better freeze-thaw stability.…”

“…Cochin et al [60] found that the batch emulsion polymerization of styrene using a cationic emulsifier proceeded smoothly leading to stable latexes at a relative high polymerization rate when a cationic initiator was used. However, coagulation occurred when anionic potassium persulfate was employed.…”

Synthesis and characterization of a pressure-sensitive adhesive based on an isobutyl acrylate / 2-ethylhexyl acrylate copolymer

“…Potassium persulfate (PPS, Sigma) was chosen as initiator, acrylamide (BASF) as hydrophilic monomer, and nonylphenol (NP20, where 20 designates the average length chain of the ethoxylate, the molar mass of which is 1084 g/mol) as a surfactant. The hydrophobic monomers (EHA and the IBA) were selected because they have boiling points higher than polymerization temperature and they have a certain degree of solubility in water, which is good for the emulsion polymerization [12].…”

Particle nucleation mechanism for the emulsion polymerization of styrene with a novel polyester emulsifier

“…[1][2][3][4] Previous investigations have developed block or graft amphiphatic polymeric emulsifiers, polyelectrolytes, and polysoap emulsifiers. [5][6][7][8][9][10] Among the various polymeric emulsifiers, polyester-based emulsifiers are of paramount concern. 3,4,[11][12][13] Almost all previous studies of polymeric emulsifiers have focused on the structural design of the molecules.…”

“…7,8 In addition, micellar nucleation is involved in polymerizations with polymeric emulsifiers. 6,9 In conventional emulsion polymerization for a low-water-soluble monomer, the monomer is emulsified into the continuous aqueous phase, monomer droplets 1-10 m in size are formed, and most of the emulsifiers are either dissolved in the continuous phase or are in the form of micelles. The large total surface area of the micelles compared with the area of the monomer droplets greatly favors the micelles in the initial absorption of aqueous-phase-formed free radicals.…”