Oligoglycidol-Functionalised Styrene Macromolecules as Reactive Surfactants in the Emulsion Polymerisation of Styrene: The Impact of Chain Length and Concentration on Particle Size and Colloidal Stability.

Kim Waulthers,Pascal Buskens,Kathleen Stout,Ryan Van Zandvoort,Evelien Baeten,Helmut Keul,Jeroen Welzen,Daniel Mann,Sam Castermans

doi:10.3390/polym12071557

Abstract

Reactive surfactants (surfmers), which are covalently attached to the surface of sub-micron sized polymer particles during emulsion polymerisation, are applied to tailor the surface functionality of polymer particles for an application of choice. We present a systematic study on the use of oligoglycidol-functionalised styrene macromolecules as surfmers in the emulsion polymerization of styrene. Firstly, we report the impact of the surfmer concentration on the particle size for polymerisations performed above and below the critical micelle concentration. Secondly, we report the influence of the oligoglycidol chain length on the particle size. Thirdly, we conducted experiments to analyse the influence of the surfmer concentration and its chain length on the colloidal stability of the aqueous polystyrene nanoparticles in sodium chloride solutions. We demonstrated that the size of polystyrene particles could be influenced by changing both the surfmer concentration and its chain length. Furthermore, we showed that the colloidal stability of the oligoglycidol-functionalized polystyrene particles is dependent on the particle size, and not directly related to the oligoglycidol chain length.

Highlights

Polymer nanoparticles are widely applied, e.g., in functional nanocomposites [1,2], nano-enabled coatings [3,4], advanced optical materials [5,6] and colloidal molecules [7,8]
The polymer chain length was controlled by adjusting the Vinyl Benzyl Alcohol (VBA):poly(ethoxy ethyl glycidyl ether) (PEEGE) ratio, and it was analysed by benzyl alcohol (VBA, see Figure S1) and ethoxy ethyl glycidyl ether (EEGE) in ring opening
We conducted a systematic study to analyse the impact of the concentration and chain length of oligoglycidol-based surfmers on the emulsion polymerisation of styrene

Summary

Introduction

Polymer nanoparticles are widely applied, e.g., in functional nanocomposites [1,2], nano-enabled coatings [3,4], advanced optical materials [5,6] and colloidal molecules [7,8]. For many of these applications controlling the surface functionality of the polymer nanoparticles is essential, e.g., to tune the interfacial tension for successful integration of the particles into composites [2] or coatings [3,4], Polymers 2020, 12, 1557; doi:10.3390/polym12071557 www.mdpi.com/journal/polymers. Reactive surfactants (surfmers) participate in the emulsion polymerisation, and are covalently connected to the particle surface This facilitates tailoring of the particle surface for the application of choice, and avoids the presence of excess surfactant in the dispersion medium. A range of different surfmers has been reported for the preparation of polymer [8,16,17,18,19,20,21,22,23], inorganic [24,25] and hybrid nanoparticles [26]

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Results

Conclusion