Porous natural-synthetic polymer composites were prepared using an alginate emulsion templating s... more Porous natural-synthetic polymer composites were prepared using an alginate emulsion templating step followed by supercritical carbon dioxide (sc-CO2) assisted impregnation (and subsequent polymerisation) of synthetic monomer mixtures. In the impregnation step, an initiator and either 2-hydroxyethylmethacrylate (HEMA), butylmethacrylate (BMA), ethyleneglycoldimethacrylate (EGDMA) or trimethylolpropanetrimethacrylate (TRIM) monomers, respectively, were used. After impregnation into the porous alginate foam, the synthetic monomer(s) were polymerised in situ, forming porous composites with increased stiffness. A number of methods were used to assess the effects of the impregnation/polymerisation process including uniaxial compression testing, scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), helium pycnometry and Fourier transform infra-red (FTIR) spectroscopy. Our results suggest that alginate foams impregnated with HEMA show higher weight gains and are stiffer than those impregnated with BMA. Such stiffer porous composites are potentially better suited than the unmodified materials in applications such as tissue engineering (cell-seeded) scaffolds, where mechanical conditioning is desired to stimulate cells for development of neo tissue growth.
In this paper, we describe the synthesis of porous, cross-linked polymethacrylate monoliths by fr... more In this paper, we describe the synthesis of porous, cross-linked polymethacrylate monoliths by free radical polymerization using 1,1,1,2-tetrafluoroethane (R134a) as the porogenic solvent. Solvent separations were simple (boiling point R134a=−26.5 °C) and the reactions were carried out at relatively low pressures (<20 bar). It was found that the surface area and the median pore diameter of the materials could be varied over a wide range (5–320 m2/g and 15 nm–5 μm, respectively) by varying the monomer concentration. By contrast, pressure had little influence on the structure of the materials due to the relatively incompressible nature of liquid R134a.
Porous natural-synthetic polymer composites were prepared using an alginate emulsion templating s... more Porous natural-synthetic polymer composites were prepared using an alginate emulsion templating step followed by supercritical carbon dioxide (sc-CO2) assisted impregnation (and subsequent polymerisation) of synthetic monomer mixtures. In the impregnation step, an initiator and either 2-hydroxyethylmethacrylate (HEMA), butylmethacrylate (BMA), ethyleneglycoldimethacrylate (EGDMA) or trimethylolpropanetrimethacrylate (TRIM) monomers, respectively, were used. After impregnation into the porous alginate foam, the synthetic monomer(s) were polymerised in situ, forming porous composites with increased stiffness. A number of methods were used to assess the effects of the impregnation/polymerisation process including uniaxial compression testing, scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), helium pycnometry and Fourier transform infra-red (FTIR) spectroscopy. Our results suggest that alginate foams impregnated with HEMA show higher weight gains and are stiffer than those impregnated with BMA. Such stiffer porous composites are potentially better suited than the unmodified materials in applications such as tissue engineering (cell-seeded) scaffolds, where mechanical conditioning is desired to stimulate cells for development of neo tissue growth.
In this paper, we describe the synthesis of porous, cross-linked polymethacrylate monoliths by fr... more In this paper, we describe the synthesis of porous, cross-linked polymethacrylate monoliths by free radical polymerization using 1,1,1,2-tetrafluoroethane (R134a) as the porogenic solvent. Solvent separations were simple (boiling point R134a=−26.5 °C) and the reactions were carried out at relatively low pressures (<20 bar). It was found that the surface area and the median pore diameter of the materials could be varied over a wide range (5–320 m2/g and 15 nm–5 μm, respectively) by varying the monomer concentration. By contrast, pressure had little influence on the structure of the materials due to the relatively incompressible nature of liquid R134a.
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