Synthesis of Emulsion-Templated Acrylic-Based Porous Polymers: From Brittle to Elastomeric

Abstract

High internal phase emulsion polymers (PolyHIPEs) are novel materials that have high porosityand interconnected open-cell structure and are used in various applications such as supports for catalytic systems, media for separation of similar molecules, and scaffolds for tissue engineering. In this study, 90% porous acrylic based polyHIPE structures with various cellular structure and mechanical characteristics were developed by using stearyl acrylate (SA), isodecyl acrylate (IDA), isobornyl methacrylate (IBMA), and divinylbenzene (DVB). Elastomeric polyHIPEs were produced from the comonomers of SA and IDA, and had high ability of recovery when the applied stress was removed. IBMA based polyHIPEs were brittle and demonstrated higher Young's modulus and compression strength than that of conventional styrene based polyHIPEs at the same void volume. Therefore, by varying the composition, it became possible to alter the mechanical properties of polyHIPEs from brittle to elastomeric, without changing the interconnected cellular structures.

Basic Principles of Emulsion Templating and Its Use as an Emerging Manufacturing Method of Tissue Engineering Scaffolds

“…Crosslinkers are the precursors with at least two reactive ends to connect primary polymer chains by forming intermolecular linkages ( Figure 9A). Using an external crosslinking agent increases the degree of crosslinking of the polymer phase, and it improves the stiffness of the materials (Tunc et al, 2012). The most known crosslinker is DVB, used in the composition of styrene HIPEs (Akay et al, 2004;Sevšek et al, 2014;Woodward et al, 2017; Figures 9B,C).…”

“…Ammonium persulphate (APS) ( Moglia et al, 2011 ) and potassium persulphate (KPS) ( Lumelsky et al, 2008 , 2009 ; Tunc et al, 2012 ) are water-soluble oxidising agents that are used as redox initiators in radical crosslinking of the macromer chains. They have been reported to be introduced into the water phase of the styrene ( Bokhari et al, 2005 ; Audouin et al, 2012 ), dextran, ( Zhou et al, 2012a ) or polypropylene fumarate (PPF) ( Christenson et al, 2007 ; Moglia et al, 2011 ) HIPEs with the concentration of 1–5% w/v of the aqueous phase.…”

Preparation of highly interconnected porous polymer microbeadsviasuspension polymerization of high internal phase emulsions for fast removal of oil spillage from aqueous environments

“…20 The emulsions consist of an external continuous monomer phase and an internal droplet phase with volume fraction of at least 0.74. 21,22 This HIPE templating method is exible and easy to control pore structure and size as well as porosity by varying the compositions of the emulsions, compared with other methods for the fabrication of porous polymers. [23][24][25] In previous reports, polyHIPEs are fabricated by various monomer precursors, such as styrene, 26,27 4-vinylbenzyl chloride, 28 methyl methacrylate, 27,29 2-hydroxyethyl methacrylate, 30 2-ethylhexyl acrylate, 31 stearyl methacrylate, 32 hexauorobutyl acrylate, 33 butyl acrylate, 34 and so on, giving mechanical properties that range from elastomeric to extremely tough and rigid.…”

Robust macroporous polymers: Using polyurethane diacrylate as property defining crosslinker

“…Pulko et al [36] prepared bendable poly-HIPE membranes based on glycidyl methacrylate, ethyleneglycol dimethacrylate and ethylhexyl methacrylate. Recently, Tunc et al [37] reported that polyHIPEs can be tailored from rigid materials to elastomers by tuning the template composition, i.e. varying the acrylate/divinylbenzene ratio within emulsion template.…”