GMA‐based emulsion‐templated solid foams: Influence of co‐crosslinker on morphology and mechanical properties

Abstract

Highly open porous polymer foams formed from high internal phase emulsions (polyHIPEs) are attracting significant interest because of their potential applications in many areas of advanced materials science. In this work, the influence of the crosslinker or co-crosslinkers of different molecular weights on the morphology and mechanical properties of polyHIPEs containing glycidyl methacrylate (GMA) was studied. Several poly(ethylene glycol) dimethacrylate (PEGDMA) crosslinkers were considered. The results show that introducing higher molecular weight crosslinkers into polyHIPEs produces a more open structure, with significantly increased compression strength and deformation at breakage. This eliminated the undesirable brittleness and chalkiness commonly found in polyHIPE materials. The Young's modulus of GMA-based polyHIPEs containing 40% poly(ethylene glycol) dimethacrylate increased by 50% and the crush strength by 400% when compared with traditional GMA/ethylene glycol dimethylacrylate polyHIPEs. This improvement in mechanical properties is expected to improve the suitability of polyHIPEs for use in a wide range of applications.

A facile fabrication of porous fluoro-polymer with excellent mechanical properties based on high internal phase emulsion templating using PLA as co-stabilizer

“…This diversity in stability could be explained to some extent by the differences in viscosity between the two systems. It has been shown that the stability of an emulsion system increases with an increase in viscosity 10,37 and the uoro-emulsion prepared with PLA showed a higher viscosity compared to the HIPE prepared without PLA. Furthermore, interfacial tension can also promote emulsion stability.…”

“…Inspection of the morphology of the porous materials post emulsion polymerization, showed that the average pore sizes of polyHIPE prepared with PLA were smaller than those produced without PLA, consistent with the observed (small) emulsion droplets sizes. The porous material prepared without PLA had the large pore structure of a conventional polyHIPE, 1,10,39 and the average pore diameter was 45.24 mm (Fig. 3A).…”

“…28 Porous material prepared by the templating method typically has a pore diameter of >5 mm and it is very difficult to obtain smaller pore diameters by this method. 1,9,10,18,19,39 Consequently, PLA would appear to have a signicant role in regulating pore size. The minimum pore size obtained in this study was 1-2 mm: the pore had an even size distribution, they were all interconnected, and they remained intact without collapse and fragmentation.…”

“…Rezanavaz and Fee showed that crosslinking agent content and molecular weight could affect the mechanical properties of porous materials. 10 Furthermore, the mechanical strength of the polyHIPE can be further enhanced by increasing the amount of crosslinking agent (DVB) in the monomer phase of the emulsions before polymerization. 43 Mechanical performance tests for samples prepared with crosslinking agent in the range 10-90 wt% are shown in Fig.…”

“…8 Candidate monomers for HIPE include styrene, acrylate, divinylbenzene, glycidyl methacrylate and so on. 9,10 Recently, the introduction of uoromonomers into the polyHIPE system has shown that polymer monoliths can be prepared with the advantages of e.g. chemical/ oxidative stability, thermal/environmental stability and excellent surface properties.…”