The Experts below are selected from a list of 109029 Experts worldwide ranked by ideXlab platform
Edward Dormier - One of the best experts on this subject based on the ideXlab platform.
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a study of structure and property changes of biodegradable polyglycolide and poly glycolide co lactide fibers during processing and in vitro degradation
Chinese Journal of Polymer Science, 2003Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Susan Lin, Jeuny Yuan, Edward DormierAbstract:Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA) fibers were investigated during several industrial processing Stages and in vitro degradation by means of wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the Orientation Stage, the PGA fibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similar conditions. In the hot-stretching and post-annealing Stages, after fibers were braided, PGA samples were found to gain more crystallinity and higher Tg than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate of degradation. DMA results showed that a great deal of internal stress that was built during Orientation and hot-stretching Stages was released in the post-annealing Stage for all PGA and PGA-co-PLA samples. During earlier Stages of in vitro degradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. The heat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLA samples, indicating the amorphous portions of the polymers lost Orientation after a short period in the buffer solution, most likely due to relaxation of the cleaved chains.
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide-co-lactide) (PGA-co-PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature (Tg) and tensile strength, but decreased the elongation at break and the heat shrinkage near Tg. In the post-annealing Stage, it was found that crystallinity, Tg and tensile strength all increased significantly while the heat shrinkage near Tg sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near Tg and in the supercooling region (Tg
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Bruce X Fu, Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide- co -lactide) (PGA- co -PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature ( T g ) and tensile strength, but decreased the elongation at break and the heat shrinkage near T g . In the post-annealing Stage, it was found that crystallinity, T g and tensile strength all increased significantly while the heat shrinkage near T g sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near T g and in the supercooling region ( T g T T m ) was greatly reduced. These results support the process of cleavage-induced crystallization.
Benjamin S Hsiao - One of the best experts on this subject based on the ideXlab platform.
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a study of structure and property changes of biodegradable polyglycolide and poly glycolide co lactide fibers during processing and in vitro degradation
Chinese Journal of Polymer Science, 2003Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Susan Lin, Jeuny Yuan, Edward DormierAbstract:Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA) fibers were investigated during several industrial processing Stages and in vitro degradation by means of wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the Orientation Stage, the PGA fibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similar conditions. In the hot-stretching and post-annealing Stages, after fibers were braided, PGA samples were found to gain more crystallinity and higher Tg than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate of degradation. DMA results showed that a great deal of internal stress that was built during Orientation and hot-stretching Stages was released in the post-annealing Stage for all PGA and PGA-co-PLA samples. During earlier Stages of in vitro degradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. The heat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLA samples, indicating the amorphous portions of the polymers lost Orientation after a short period in the buffer solution, most likely due to relaxation of the cleaved chains.
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide-co-lactide) (PGA-co-PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature (Tg) and tensile strength, but decreased the elongation at break and the heat shrinkage near Tg. In the post-annealing Stage, it was found that crystallinity, Tg and tensile strength all increased significantly while the heat shrinkage near Tg sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near Tg and in the supercooling region (Tg
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Bruce X Fu, Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide- co -lactide) (PGA- co -PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature ( T g ) and tensile strength, but decreased the elongation at break and the heat shrinkage near T g . In the post-annealing Stage, it was found that crystallinity, T g and tensile strength all increased significantly while the heat shrinkage near T g sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near T g and in the supercooling region ( T g T T m ) was greatly reduced. These results support the process of cleavage-induced crystallization.
Gavin Chen - One of the best experts on this subject based on the ideXlab platform.
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a study of structure and property changes of biodegradable polyglycolide and poly glycolide co lactide fibers during processing and in vitro degradation
Chinese Journal of Polymer Science, 2003Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Susan Lin, Jeuny Yuan, Edward DormierAbstract:Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA) fibers were investigated during several industrial processing Stages and in vitro degradation by means of wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the Orientation Stage, the PGA fibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similar conditions. In the hot-stretching and post-annealing Stages, after fibers were braided, PGA samples were found to gain more crystallinity and higher Tg than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate of degradation. DMA results showed that a great deal of internal stress that was built during Orientation and hot-stretching Stages was released in the post-annealing Stage for all PGA and PGA-co-PLA samples. During earlier Stages of in vitro degradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. The heat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLA samples, indicating the amorphous portions of the polymers lost Orientation after a short period in the buffer solution, most likely due to relaxation of the cleaved chains.
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide-co-lactide) (PGA-co-PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature (Tg) and tensile strength, but decreased the elongation at break and the heat shrinkage near Tg. In the post-annealing Stage, it was found that crystallinity, Tg and tensile strength all increased significantly while the heat shrinkage near Tg sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near Tg and in the supercooling region (Tg
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Bruce X Fu, Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide- co -lactide) (PGA- co -PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature ( T g ) and tensile strength, but decreased the elongation at break and the heat shrinkage near T g . In the post-annealing Stage, it was found that crystallinity, T g and tensile strength all increased significantly while the heat shrinkage near T g sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near T g and in the supercooling region ( T g T T m ) was greatly reduced. These results support the process of cleavage-induced crystallization.
Jack Zhou - One of the best experts on this subject based on the ideXlab platform.
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a study of structure and property changes of biodegradable polyglycolide and poly glycolide co lactide fibers during processing and in vitro degradation
Chinese Journal of Polymer Science, 2003Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Susan Lin, Jeuny Yuan, Edward DormierAbstract:Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA) fibers were investigated during several industrial processing Stages and in vitro degradation by means of wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the Orientation Stage, the PGA fibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similar conditions. In the hot-stretching and post-annealing Stages, after fibers were braided, PGA samples were found to gain more crystallinity and higher Tg than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate of degradation. DMA results showed that a great deal of internal stress that was built during Orientation and hot-stretching Stages was released in the post-annealing Stage for all PGA and PGA-co-PLA samples. During earlier Stages of in vitro degradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. The heat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLA samples, indicating the amorphous portions of the polymers lost Orientation after a short period in the buffer solution, most likely due to relaxation of the cleaved chains.
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide-co-lactide) (PGA-co-PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature (Tg) and tensile strength, but decreased the elongation at break and the heat shrinkage near Tg. In the post-annealing Stage, it was found that crystallinity, Tg and tensile strength all increased significantly while the heat shrinkage near Tg sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near Tg and in the supercooling region (Tg
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Bruce X Fu, Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide- co -lactide) (PGA- co -PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature ( T g ) and tensile strength, but decreased the elongation at break and the heat shrinkage near T g . In the post-annealing Stage, it was found that crystallinity, T g and tensile strength all increased significantly while the heat shrinkage near T g sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near T g and in the supercooling region ( T g T T m ) was greatly reduced. These results support the process of cleavage-induced crystallization.
Ilya Koyfman - One of the best experts on this subject based on the ideXlab platform.
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a study of structure and property changes of biodegradable polyglycolide and poly glycolide co lactide fibers during processing and in vitro degradation
Chinese Journal of Polymer Science, 2003Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Susan Lin, Jeuny Yuan, Edward DormierAbstract:Structure and properties of bioabsorbable polyglycolide (PGA) and poly(glycolide-co-lactide) (PGA-co-PLA) fibers were investigated during several industrial processing Stages and in vitro degradation by means of wide-angle X-ray diffraction (WAXD), dynamic mechanical analysis (DMA) and mechanical property tests. In the Orientation Stage, the PGA fibers were found to have higher degrees of crystallinity than corresponding PGA-co-PLA samples produced under similar conditions. In the hot-stretching and post-annealing Stages, after fibers were braided, PGA samples were found to gain more crystallinity and higher Tg than PGA-co-PLA samples. The higher crystallinity in PGA fibers resulted in a slower rate of degradation. DMA results showed that a great deal of internal stress that was built during Orientation and hot-stretching Stages was released in the post-annealing Stage for all PGA and PGA-co-PLA samples. During earlier Stages of in vitro degradation, both PGA and PGA-co-PLA samples exhibited the typical cleavage-induced crystallization mechanism. The heat shrinkage in the glass transition area was found to disappear after 6-8 days of degradation for all PGA and PGA-co-PLA samples, indicating the amorphous portions of the polymers lost Orientation after a short period in the buffer solution, most likely due to relaxation of the cleaved chains.
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide-co-lactide) (PGA-co-PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature (Tg) and tensile strength, but decreased the elongation at break and the heat shrinkage near Tg. In the post-annealing Stage, it was found that crystallinity, Tg and tensile strength all increased significantly while the heat shrinkage near Tg sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near Tg and in the supercooling region (Tg
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structure and property studies of bioabsorbable poly glycolide co lactide fiber during processing and in vitro degradation
Polymer, 2002Co-Authors: Bruce X Fu, Benjamin S Hsiao, Gavin Chen, Jack Zhou, Ilya Koyfman, Dennis D Jamiolkowski, Edward DormierAbstract:Abstract Structure and properties of a bioabsorbable poly(glycolide- co -lactide) (PGA- co -PLA) fiber during several processing Stages and the final in vitro degradation Stage were investigated by means of wide-angle X-ray diffraction, dynamic mechanical analysis and mechanical property tests. In the Orientation Stage, an increase in the temperature of the first encountered Orientation roll resulted in a lower level of crystallinity and larger crystallites. The temperature of the second encountered pre-annealing roll (PR) imposed a smaller effect on the structure. In the hot-stretching Stage after fibers were braided, the maximum crystallinity was achieved at around 126 °C. Higher hot-stretching temperatures increased the crystal size, glass transition temperature ( T g ) and tensile strength, but decreased the elongation at break and the heat shrinkage near T g . In the post-annealing Stage, it was found that crystallinity, T g and tensile strength all increased significantly while the heat shrinkage near T g sharply decreased after annealing. This suggests that the internal stress accumulated in the Orientation and hot-stretching Stages can be effectively reduced by post-annealing. During in vitro degradation, crystallinity was found to increase with time while the heat shrinkage near T g and in the supercooling region ( T g T T m ) was greatly reduced. These results support the process of cleavage-induced crystallization.
