Emulsion polymerization mechanisms and kinetics
C.S. Chern *
Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road,
Section 4, Taipei 106, Taiwan, ROC
Received 15 August 2005; received in revised form 24 November 2005; accepted 15 February 2006
Available online 5 April 2006
Abstract
Emulsion polymerization involves the propagation reaction of free radicals with monomer molecules in a very large number of
discrete polymer particles (1016–1018 dmK3) dispersed in the continuous aqueous phase. The nucleation and growth of latex
particles control the colloidal and physical properties of latex products. This review article focused on the polymerization
mechanisms and kinetics involved in such a heterogeneous polymerization system over the preceding 10-year period. First, an
overview of the general features of emulsion polymerization was given, followed by the discussion of several techniques useful for
studying the related polymerization mechanisms and kinetics. Emulsion polymerizations using different stabilizers were studied
extensively in the last few years and representative publications were reviewed. The performance properties of some specialty
polymerizable, degradable or polymeric surfactants and surface-active initiators were also evaluated in emulsion polymerization.
At present, the particle nucleation process is still not well understood and deserves more research efforts. This article continued to
discuss the origin of non-uniform latex particles from both the thermodynamic and kinetic points of view. This was followed by the
discussion of various reaction parameters that had significant effects on the development of particle morphology. Recent studies on
the polymerization in non-uniform polymer particles were then reviewed. Finally, the polymerization mechanisms, kinetics and
colloidal stability involved in the versatile semibatch emulsion polymerization were reviewed extensively.
q 2006 Elsevier Ltd. All rights reserved.
Keywords: Emulsion polymerization; Latex particles; Polymerization mechanisms; Particle nucleation; Particle growth; Kinetics
C.S. Chern *
Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road,
Section 4, Taipei 106, Taiwan, ROC
Received 15 August 2005; received in revised form 24 November 2005; accepted 15 February 2006
Available online 5 April 2006
Abstract
Emulsion polymerization involves the propagation reaction of free radicals with monomer molecules in a very large number of
discrete polymer particles (1016–1018 dmK3) dispersed in the continuous aqueous phase. The nucleation and growth of latex
particles control the colloidal and physical properties of latex products. This review article focused on the polymerization
mechanisms and kinetics involved in such a heterogeneous polymerization system over the preceding 10-year period. First, an
overview of the general features of emulsion polymerization was given, followed by the discussion of several techniques useful for
studying the related polymerization mechanisms and kinetics. Emulsion polymerizations using different stabilizers were studied
extensively in the last few years and representative publications were reviewed. The performance properties of some specialty
polymerizable, degradable or polymeric surfactants and surface-active initiators were also evaluated in emulsion polymerization.
At present, the particle nucleation process is still not well understood and deserves more research efforts. This article continued to
discuss the origin of non-uniform latex particles from both the thermodynamic and kinetic points of view. This was followed by the
discussion of various reaction parameters that had significant effects on the development of particle morphology. Recent studies on
the polymerization in non-uniform polymer particles were then reviewed. Finally, the polymerization mechanisms, kinetics and
colloidal stability involved in the versatile semibatch emulsion polymerization were reviewed extensively.
q 2006 Elsevier Ltd. All rights reserved.
Keywords: Emulsion polymerization; Latex particles; Polymerization mechanisms; Particle nucleation; Particle growth; Kinetics