The Experts below are selected from a list of 29259 Experts worldwide ranked by ideXlab platform
Ifty Ahmed - One of the best experts on this subject based on the ideXlab platform.
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in situ Polymerisation of fully bioresorbable polycaprolactone phosphate glass fibre composites in vitro degradation and mechanical properties
Journal of The Mechanical Behavior of Biomedical Materials, 2016Co-Authors: Menghao Chen, Andrew J Parsons, Reda M Felfel, C D Rudd, Derek J Irvine, Ifty AhmedAbstract:Fully bioresorbable composites have been investigated in order to replace metal implant plates used for hard tissue repair. Retention of the composite mechanical properties within a physiological environment has been shown to be significantly affected due to loss of the integrity of the fibre/matrix interface. This study investigated phosphate based glass fibre (PGF) reinforced polycaprolactone (PCL) composites with 20%, 35% and 50% fibre volume fractions (Vf) manufactured via an In-Situ Polymerisation (ISP) process and a conventional laminate stacking (LS) followed by compression moulding. Reinforcing efficiency between the LS and ISP manufacturing process was compared, and the ISP composites revealed significant improvements in mechanical properties when compared to LS composites. The degradation profiles and mechanical properties were monitored in phosphate buffered saline (PBS) at 37°C for 28 days. ISP composites revealed significantly less media uptake and mass loss (p<0.001) throughout the degradation period. The initial flexural properties of ISP composites were substantially higher (p<0.0001) than those of the LS composites, which showed that the ISP manufacturing process provided a significantly enhanced reinforcement effect than the LS process. During the degradation study, statistically higher flexural property retention profiles were also seen for the ISP composites compared to LS composites. SEM micrographs of fracture surfaces for the LS composites revealed dry fibre bundles and poor fibre dispersion with polymer rich zones, which indicated poor interfacial bonding, distribution and adhesion. In contrast, evenly distributed fibres without dry fibre bundles or polymer rich zones, were clearly observed for the ISP composite samples, which showed that a superior fibre/matrix interface was achieved with highly improved adhesion.
Reda M Felfel - One of the best experts on this subject based on the ideXlab platform.
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in situ Polymerisation of fully bioresorbable polycaprolactone phosphate glass fibre composites in vitro degradation and mechanical properties
Journal of The Mechanical Behavior of Biomedical Materials, 2016Co-Authors: Menghao Chen, Andrew J Parsons, Reda M Felfel, C D Rudd, Derek J Irvine, Ifty AhmedAbstract:Fully bioresorbable composites have been investigated in order to replace metal implant plates used for hard tissue repair. Retention of the composite mechanical properties within a physiological environment has been shown to be significantly affected due to loss of the integrity of the fibre/matrix interface. This study investigated phosphate based glass fibre (PGF) reinforced polycaprolactone (PCL) composites with 20%, 35% and 50% fibre volume fractions (Vf) manufactured via an In-Situ Polymerisation (ISP) process and a conventional laminate stacking (LS) followed by compression moulding. Reinforcing efficiency between the LS and ISP manufacturing process was compared, and the ISP composites revealed significant improvements in mechanical properties when compared to LS composites. The degradation profiles and mechanical properties were monitored in phosphate buffered saline (PBS) at 37°C for 28 days. ISP composites revealed significantly less media uptake and mass loss (p<0.001) throughout the degradation period. The initial flexural properties of ISP composites were substantially higher (p<0.0001) than those of the LS composites, which showed that the ISP manufacturing process provided a significantly enhanced reinforcement effect than the LS process. During the degradation study, statistically higher flexural property retention profiles were also seen for the ISP composites compared to LS composites. SEM micrographs of fracture surfaces for the LS composites revealed dry fibre bundles and poor fibre dispersion with polymer rich zones, which indicated poor interfacial bonding, distribution and adhesion. In contrast, evenly distributed fibres without dry fibre bundles or polymer rich zones, were clearly observed for the ISP composite samples, which showed that a superior fibre/matrix interface was achieved with highly improved adhesion.
C D Rudd - One of the best experts on this subject based on the ideXlab platform.
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in situ Polymerisation of fully bioresorbable polycaprolactone phosphate glass fibre composites in vitro degradation and mechanical properties
Journal of The Mechanical Behavior of Biomedical Materials, 2016Co-Authors: Menghao Chen, Andrew J Parsons, Reda M Felfel, C D Rudd, Derek J Irvine, Ifty AhmedAbstract:Fully bioresorbable composites have been investigated in order to replace metal implant plates used for hard tissue repair. Retention of the composite mechanical properties within a physiological environment has been shown to be significantly affected due to loss of the integrity of the fibre/matrix interface. This study investigated phosphate based glass fibre (PGF) reinforced polycaprolactone (PCL) composites with 20%, 35% and 50% fibre volume fractions (Vf) manufactured via an In-Situ Polymerisation (ISP) process and a conventional laminate stacking (LS) followed by compression moulding. Reinforcing efficiency between the LS and ISP manufacturing process was compared, and the ISP composites revealed significant improvements in mechanical properties when compared to LS composites. The degradation profiles and mechanical properties were monitored in phosphate buffered saline (PBS) at 37°C for 28 days. ISP composites revealed significantly less media uptake and mass loss (p<0.001) throughout the degradation period. The initial flexural properties of ISP composites were substantially higher (p<0.0001) than those of the LS composites, which showed that the ISP manufacturing process provided a significantly enhanced reinforcement effect than the LS process. During the degradation study, statistically higher flexural property retention profiles were also seen for the ISP composites compared to LS composites. SEM micrographs of fracture surfaces for the LS composites revealed dry fibre bundles and poor fibre dispersion with polymer rich zones, which indicated poor interfacial bonding, distribution and adhesion. In contrast, evenly distributed fibres without dry fibre bundles or polymer rich zones, were clearly observed for the ISP composite samples, which showed that a superior fibre/matrix interface was achieved with highly improved adhesion.
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physical and biocompatibility properties of poly e caprolactone produced using in situ Polymerisation a novel manufacturing technique for long fibre composite materials
Biomaterials, 2000Co-Authors: T J Corden, C D Rudd, I A Jones, P Christian, S Downes, K E McdougallAbstract:Preliminary investigations into a novel process for the production of poly-epsilon-caprolactone (PCL) to be used as a matrix material in a bioabsorbable composite material are detailed. This material is primarily being developed as a bone substitute for use in maxillofacial reconstructive surgery, however, the technique described could be adapted to other areas where bioabsorbable composite materials may be used. The development of a totally bioabsorbable long-fibre composite material would allow a two-stage degradation to occur with the matrix material degrading first leaving a scaffold structure of degradable fibres which would be absorbed at a later stage. Caprolactone monomer was polymerised in situ within a tool cavity to produce a net shape moulding. Inclusion of a fibre preform within the tool cavity which was impregnated by the liquid monomer produces a long-fibre composite material. PCL with a range of molecular weights has been produced using this liquid moulding technique to assess the physical and biocompatibility properties compared to commercially available PCL. Osteoblast-like cells derived from human craniofacial bone (CFC) have been used to assess the in vitro biocompatibility of the PCL. The results show that high-quality PCL with a narrow molecular weight distribution and properties similar to commercially available PCL can be produced using this technique. Polymerisation of the monomer around a woven fibre preform made of a poly(lactic acid) (PLA)/poly(glycolic acid) (PGA) copolymer (vicryl mesh) produced a bioabsorbable long-fibre composite material. Further work is ongoing to develop this system towards a method for improving craniofacial bone reconstruction.
Menghao Chen - One of the best experts on this subject based on the ideXlab platform.
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in situ Polymerisation of fully bioresorbable polycaprolactone phosphate glass fibre composites in vitro degradation and mechanical properties
Journal of The Mechanical Behavior of Biomedical Materials, 2016Co-Authors: Menghao Chen, Andrew J Parsons, Reda M Felfel, C D Rudd, Derek J Irvine, Ifty AhmedAbstract:Fully bioresorbable composites have been investigated in order to replace metal implant plates used for hard tissue repair. Retention of the composite mechanical properties within a physiological environment has been shown to be significantly affected due to loss of the integrity of the fibre/matrix interface. This study investigated phosphate based glass fibre (PGF) reinforced polycaprolactone (PCL) composites with 20%, 35% and 50% fibre volume fractions (Vf) manufactured via an In-Situ Polymerisation (ISP) process and a conventional laminate stacking (LS) followed by compression moulding. Reinforcing efficiency between the LS and ISP manufacturing process was compared, and the ISP composites revealed significant improvements in mechanical properties when compared to LS composites. The degradation profiles and mechanical properties were monitored in phosphate buffered saline (PBS) at 37°C for 28 days. ISP composites revealed significantly less media uptake and mass loss (p<0.001) throughout the degradation period. The initial flexural properties of ISP composites were substantially higher (p<0.0001) than those of the LS composites, which showed that the ISP manufacturing process provided a significantly enhanced reinforcement effect than the LS process. During the degradation study, statistically higher flexural property retention profiles were also seen for the ISP composites compared to LS composites. SEM micrographs of fracture surfaces for the LS composites revealed dry fibre bundles and poor fibre dispersion with polymer rich zones, which indicated poor interfacial bonding, distribution and adhesion. In contrast, evenly distributed fibres without dry fibre bundles or polymer rich zones, were clearly observed for the ISP composite samples, which showed that a superior fibre/matrix interface was achieved with highly improved adhesion.
Fayna Mammeri - One of the best experts on this subject based on the ideXlab platform.
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elaboration and mechanical characterization of nanocomposites thin films part i determination of the mechanical properties of thin films prepared by in situ Polymerisation of tetraethoxysilane in poly methyl methacrylate
Journal of The European Ceramic Society, 2006Co-Authors: Fayna Mammeri, Eric Le Bourhis, Laurence Rozes, Clement SanchezAbstract:Abstract The sol–gel process allows to design hybrid organic–inorganic materials constituted by organic molecules or macromolecules and inorganic metal oxo-polymers interpenetrated at the nanometer scale. These hybrids were deposited as functional coatings with tunable thickness on float glass substrates. Good adhesion and mechanical behaviour of the coatings are required to keep their functionality in time hence; the performance of the PMMA-SiO 2 based thin films was investigated using nanoindentation. This study validates nanoindentation measurements as an appropriate technique to characterize hybrid organic–inorganic thin films, despite visco-elastic behaviours. Specific analysis procedures and the use of appropriate models allowed us to determine the indentation modulus and hardness of the hybrid layers reproductively. The structure and the mechanical behaviour are reported for thin films as a function of the fraction of silica.
