Microemulsion polymerization of siloxane with nonionic surfactants as emulsifiers

• Published in: Journal of applied polymer science Vol. 89; no. 13; pp. 3587 - 3593
• Main Authors: Zhang, Dunming, Jiang, Xiqun, Yang, Changzheng
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 23.09.2003; Wiley
• Subjects: Applied sciences; emulsion copolymerization; Exact sciences and technology; Inorganic and organomineral polymers; Physicochemistry of polymers; polysiloxanes; Preparation; silicones; TEM; Ring opening polymerization; Dimethylsiloxane polymer; Transparency; Nanoparticle; Non ionic surfactant; Surfactant polymer; Cosurfactant; Experimental study; Property processing relationship; Latex; Ethylene oxide polymer; silicones; Preparation; polysiloxanes; Anionic polymerization; emulsion copolymerization; Kinetics; Oil water microemulsion; TEM
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.12585

Polysiloxane nanolatices were prepared by the microemulsion polymerization of octamethylcyclotetrasiloxane (D4) with nonionic polyoxyethylene alkyl ether and polyoxyethylene aryl ether as surfactants, ethylene glycol or aminoethanol as a cosurfactant, and potassium hydroxide or dipotassium dimethylsilanolate (I) as an initiator. The effect of the different initiators and the amount of cosurfactant on the microemulsion polymerization rate of D4 was investigated. The initiator, potassium hydroxide, had a similar catalytic activity to I, and adding the cosurfactant changed a common siloxane emulsion to a microemulsion. At a same reaction conditions, the polymerization rate of D4 with aminoethanol as a cosurfactant was much faster than that of ethylene glycol. The kinetics of this siloxane microemulsion polymerization was consistent with Morgen‐Kaler theory. The transparency value of the resultant polysiloxane nanolatex was more than 95% when the amount of ethylene glycol was more than 25% and the siloxane amount was about 30 wt % of the reaction mixture. A nanolatex of polydimethylsiloxane‐co‐polyvinylmethylsiloxane, which was crosslinked with potassium persulfate, revealed that the mean diameter of the droplets was 32 nm with a narrow distribution. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3587–3593, 2003