Elsevier

Progress in Polymer Science

Volume 39, Issue 10, October 2014, Pages 1797-1826
Progress in Polymer Science

Challenges for industrialization of miniemulsion polymerization

https://doi.org/10.1016/j.progpolymsci.2014.02.009Get rights and content

Abstract

Miniemulsion polymerization facilitates the synthesis complex materials that cannot be produced otherwise. These materials have a broad range of potential applications including among others adhesives, coatings, anticounterfeiting, textile pigments, bio-based polymer dispersions, gene and drug delivery, anti-viral therapy, tissue engineering, catalyst supports, polymeric photoresists, energy storage and self-healing agents. However, 40 years after the pioneering work of Ugelstad, El-Aasser and Vanderhoff the promises have not been fulfilled and the presence of miniemulsion polymerization in commercial products is scarce. This article reviews the advances in the field, discusses the reasons for this delay and analyzes the challenges that have to be overcome in order to fully use this process in commercial practice.

Introduction

Miniemulsion polymerization [1], [2], [3], [4], [5], [6], [7], [8], [9] seems to be the perfect technique to synthesize complex materials that cannot be produced otherwise. Claimed applications of materials synthesized by means of miniemulsion polymerization include adhesives [10], [11], [12], [13]; anti-reflection [14], anticorrosive [15], [16] and UV resistant [17] coatings; anticounterfeiting [18]; textile pigments [19]; bio-based polymer dispersions [20]; gene and drug delivery [22], [23], [24], [25], [26], [27]; anti-viral therapy [28]; low viscosity high solids dispersions [29], [30], [31]; chemosensors [32], [33], [34], [35]; polyolefin waterborne dispersions [36], [37], [38], [39]; catalyst supports [40]; enzymatic polymerization [41]; controlled free radical polymerization [42], [43], [44], [45], [46], [47], [48], [49], [50]; responsive materials [51], [52]; photoswitchable fluorescent particles [53]; encapsulation [54], [55], [56], [57], [58]; polymer fillers [59]; polymeric photoresists [60]; light emitting diodes [61]; night-vision displays [62]; multicolor optical coding [63]; ultrabright fluorescent polymer nanoparticles [64]; single photon emission quantum dots [65]; tissue engineering [56], [66], [67], [68]; energy storage [69], [70], [71], [72], [73]; glass and ceramics coatings [57]; DNA separation [26], [74]; surface-enhanced Raman scattering substrates [75]; self-healing agents [58] and dielectric elastomer actuators [76]. However, 40 years after the pioneering work of Ugelstad et al. [1] the presence of miniemulsion polymerization in commercial products is still scarce.

This article reviews advances in the field, discusses the reasons for this delay and analyzes the challenges that have to be overcome in order to fully use this process in commercial practice.

Section snippets

Industrial constraints for miniemulsion polymerization

The performance of the materials mentioned above is determined by the characteristics of the particles: particle size and size distribution; polymer functionality and architecture; molecular weight distribution (MWD); number, type and relative amount of the phases; particle composition distribution; and particle morphology (including the characteristics of the surface of the particles). In addition for biomedical applications, biocompatibility is a must. These materials are

Miniemulsification

Miniemulsification adds complexity and cost (investment, energy consumption) to the process. Therefore, at first sight, phase inversion emulsification is an attractive way to produce miniemulsions as it does not involve the use any special emulsification device and the energy consumption is modest. Transitional phase inversion involves an induced change of the surfactant affinity [83], [84] that, among other ways, can be achieved by changing the temperature. However, in order to obtain small

Droplet nucleation

For most formulations, the miniemulsion consists of a dispersion of composite droplets colloidally stabilized by surfactants. Because of cost and performance reasons, the amount of surfactant is limited, so that the droplets are not completely covered by surfactant, and there are no micelles in the system. The objective in miniemulsion polymerization is to transform the composite droplets into composite polymer particles minimizing the heterogeneity in particle composition. The challenges

High monomer conversion/minimizing the residual monomer

Polymerizations rarely proceed until completion and therefore a certain amount of monomer remains in the product after polymerization (typically in the range of thousands parts per million range in conventional emulsion polymerization [237]). The problem is more acute when polymer–polymer hybrids are prepared by polymerization of miniemulsion droplets containing preformed resins as in this case unacceptable high concentrations of residual monomer due to a limiting monomer conversion have been

Controlling polymer functionality and architecture

Miniemulsion polymerization has been used to synthesize polymers and polymer hybrids by both chain growth polymerization (free radical, controlled free radical, anionic, cationic and coordination) and step growth polymerization (polyaddition and polycondensation). However, not all of them are equally promising for industrial implementation.

Particle morphology

The most attractive feature of miniemulsion polymerization is that it opens the possibility of synthesizing complex colloidal materials. Particle morphology is a key characteristic of these materials as it determines performance. Experimental evidence reported in literature shows that widely different particle morphologies are attainable by this technique [10], [17], [18], [24], [54], [55], [65], [68], [151], [165], [181], [245], [301], [302], [303], [304], [305]. Industrialization of

Inverse miniemulsion polymerization

In inverse miniemulsions, submicron droplets of solutions of highly hydrophilic monomers are dispersed in a continuous hydrophobic medium. Although solvents as formamide, dimethyl sulfoxide and dimethyl formamide can in principle be used [360] to prepare the monomer solutions, water is the most commonly used solvent [361], [362], [363], [364]. Similar to the inverse emulsion polymerization [365], [366], [367], low HLB surfactants are used to colloidally stabilize the system [361], [362], [368]

Summary

The main achievements and challenges associated to the steps involved in the synthesis of materials by miniemulsion polymerization are summarized in the following.

Acknowledgments

Diputación Foral de Gipuzkoa, University of Basque Country (UFI 11/56), Basque Government (GVIT373-10 and Etortek Nanoiker IE11-304) and Ministerio de Economía y Competitividad (CTQ2011-25572) are grateful acknowledged for their financial support.

References (414)

  • M.F. Cunningham

    Controlled/living radical polymerization in aqueous dispersed systems

    Prog Polym Sci

    (2008)
  • X. Yin et al.

    Viscoelasticity of shell-crosslinked core–shell nanoparticles filled polystyrene melt

    Polymer

    (2012)
  • S.A. Bencherif et al.

    Nanostructured hybrid hydrogels prepared by a combination of atom transfer radical polymerization and free radical polymerization

    Biomaterials

    (2009)
  • G.H. Zhang et al.

    Synthesis, characterization and thermal properties of novel nanoencapsulated phase change materials for thermal energy storage

    Sol Energy

    (2012)
  • Z.H. Chen et al.

    Preparation, characterization and thermal properties of nanocapsules containing phase change material n-dodecanol by miniemulsion polymerization with polymerizable emulsifier

    Appl Energy

    (2012)
  • D. Shao et al.

    Monodispersed magnetite/silica composite microspheres: preparation and application for plasmid DNA purification

    Colloids Surf A

    (2008)
  • C.S. Chern

    Emulsion polymerization mechanisms and kinetics

    Prog Polym Sci

    (2006)
  • N. Anton et al.

    The universality of the low-energy nano-emulsification

    Int J Pharm

    (2009)
  • J.L. Keddie

    Film formation of latex

    Mater Sci Eng Rep

    (1997)
  • S. Sajjadi et al.

    Catastrophic phase inversion of abnormal emulsions in the vicinity of the locus of transitional inversion

    Colloids Surf A

    (2004)
  • S.B. Campbell et al.

    Miniemulsification by catastrophic phase inversion

    Chem Eng J

    (2012)
  • O. Behrend et al.

    Influence of continuous phase viscosity on emulsification by ultrasound

    Ultrason Sonochem

    (2000)
  • Y.F. Maa et al.

    Liquid–liquid emulsification by rotor/stator homogenization

    J Controlled Release

    (1996)
  • S.M. Joscelyne et al.

    Membrane emulsification—a literature review

    J Membr Sci

    (2000)
  • R.K. Thakur et al.

    Static mixers in the process industries. A review

    Chem Eng Res Des

    (2003)
  • K. Ouzineb et al.

    Homogenization devices for the production of miniemulsions

    Chem Eng Sci

    (2006)
  • J. Ugelstad et al.

    Emulsion polymerization: initiation of polymerization in monomer droplets

    J Polym Sci Polym Lett Ed

    (1973)
  • M.S. El-Aasser et al.

    Preparation of latexes using miniemulsions in polymeric dispersions

  • P.J. Blythe et al.

    Recent advances in miniemulsion polymerization

    Macromol Symp

    (2000)
  • I. Capek et al.

    Radical polymerization in direct mini-emulsion systems

    Adv Polym Sci

    (2001)
  • F.J. Schork et al.

    Miniemulsion polymerization

    Adv Polym Sci

    (2005)
  • K. Landfester

    Miniemulsion polymerization and the structure of polymer and hybrid nanoparticles

    Angew Chem Int Ed

    (2009)
  • J. Fauchau et al.

    Miniemulsion polymerization for synthesis of structured clay/polymer nanocomposites: short review and recent advances

    Polymer

    (2010)
  • A. Agirre et al.

    Waterborne, semicrystalline, pressure-sensitive adhesives with temperature-responsiveness and optimum properties

    ACS Appl Mater Interfaces

    (2010)
  • G.E. Fonseca et al.

    Miniemulsion vs. conventional emulsion polymerization for pressuresensitive adhesives production

    Ind Eng Chem Res

    (2010)
  • A. Lopez et al.

    Waterborne polyurethaneacrylic hybrid nanoparticles by miniemulsion polymerization: applications in pressure-sensitive adhesives

    Langmuir

    (2011)
  • R. Udagama et al.

    Mechanical properties of adhesive films obtained from PU–acrylic hybrid particles

    Macromolecules

    (2011)
  • Z. Sun et al.

    Fabrication of non-collapsed hollow polymeric nanoparticles with shell thickness in the order of ten nanometres and antireflection coatings

    Soft Matter

    (2011)
  • S. Bhadra et al.

    Polyaniline based anticorrosive and anti-molding coatins

    J Chem Eng Mater Sci

    (2011)
  • M. Aguirre et al.

    UV screening clear coats based on encapsulated CeO2 hybrid latexes

    J Mater Chem A

    (2013)
  • N.A. Harun et al.

    A miniemulsion polymerization technique for encapsulation of silicon quantum dots in polymer nanoparticles

    Nanoscale

    (2011)
  • L.A.W. Abdou et al.

    Synthesis of nanoscale binders through mini emulsion polymerization for textile pigment applications

    Ind Eng Chem Res

    (2013)
  • M. Moreno et al.

    Biobased-waterborne homopolymers from oleic acid derivatives

    J Polym Sci Part A Polym Chem

    (2012)
  • S. Lorenz et al.

    The softer and more hydrophobic the better: influence of the side chain of polymethacrylate nanoparticles for cellular uptake

    Macromol Biosci

    (2010)
  • J. Ramos et al.

    Surfactant-free miniemulsion polymerization as a simple synthetic route to a successful encapsulation of magnetite nanoparticles

    Langmuir

    (2011)
  • G. Baier et al.

    Performing encapsulation of dsDNA and a polymerase chain reaction (PCR) inside nanocontainers using the inverse miniemulsion process

    Int J Artif Organs

    (2012)
  • L.B. Fonseca et al.

    Production of PMMA nanoparticles loaded with praziquantel through “in situ” miniemulsion polymerization

    Macromol React Eng

    (2013)
  • N. Sankarakumar et al.

    Preventing viral infections with polymeric virus catchers: a novel nanotechnological approach to anti-viral therapy

    J Mater Chem B

    (2013)
  • M.J. Unzue et al.

    Semicontinuous miniemulsion terpolymerization: effect of the operation conditions

    J Appl Polym Sci

    (1993)
  • M. do Amaral et al.

    Synthesis of high-solids content monodisperse large sized latex by miniemulsion polymerization

    J Polym Sci Part A Polym Chem

    (2004)
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