采用同轴静电纺丝技术制备聚乳酸(PLA)-聚己内酯(PCL)核-壳结构复合纤维.利用扫描电子显微镜(SEM)观察纺丝电压、收集距离和核层-壳层溶液推进速度对PLA-PCL核-壳结构复合纤维形貌的影响.通过透射扫描电子显微镜(TEM)分析核层-壳层溶液...采用同轴静电纺丝技术制备聚乳酸(PLA)-聚己内酯(PCL)核-壳结构复合纤维.利用扫描电子显微镜(SEM)观察纺丝电压、收集距离和核层-壳层溶液推进速度对PLA-PCL核-壳结构复合纤维形貌的影响.通过透射扫描电子显微镜(TEM)分析核层-壳层溶液推进速度对PLA-PCL核-壳结构形成的影响.研究结果表明:当核-壳溶液推进速度为0.1-0.2和0.1-0.3 m L/h时形成了清晰的核-壳结构;随着壳层溶液推进速度加快,PLA-PCL复合纤维核层含量降低,增加纺丝电压能够有效地降低复合纤维平均直径,而增大收集距离使复合纤维平均直径先降低后增加.展开更多
The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficien...The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficient biomechanical properties,blended films composed of silk fibroin( SF) and poly( ε-caprolactone)( PCL) were fabricated by electrospinning in this study. Scanning electron microscope( SEM), X-ray diffraction( XRD),thermal analysis,Fourier transform-infrared( FT-IR),Raman spectra,mechanical testing,and water solubility were used to characterize the morphological, structural and mechanical properties of the blended electrospinning films. Results showed that the diameter of the blended fiber was distributed between 600 and1000 nm,and the fiber diameter increased as the PCL content increased. There is no obvious phase separation due to the similarity and intermiscibility,as well as the interactions( mainly hydrogen bonds), between the two polymers. Meanwhile, the secondary structures of SF changed from random coils and Silk I to Silk II because of the interactions between SF and PCL. For this reason,the tensile strength and elongation at break of the electrospinning films improved significantly,and the water solubility decreased. In conclusion,the blended electrospinning films fabricated in this study showed satisfying mechanical properties and water insolubilities,and they may be promising biomaterials for applications in tissue engineering for blood vessels,nerve conduits,tendons,ligaments and other tissues.展开更多
Poly(lactic acid)(PLA) was blended with various polycaprolactone(PCL) components through the melt blending process for toughening modification on PLA.The tensile testing,scanning electron microscope(SEM) and different...Poly(lactic acid)(PLA) was blended with various polycaprolactone(PCL) components through the melt blending process for toughening modification on PLA.The tensile testing,scanning electron microscope(SEM) and differential scanning calorimetry(DSC) were implemented to analyze mechanical properties,disperse morphology,thermal properties and compatibility of composite materials,respectively.The shape memory performance of PCL/PLA composites was also investigated.The results showed that the elongation at break of composites increased by 10 and 15 times than pure PLA with adding 20% and30% by weight of PCL,and the yield strength retention rates were77% and 67%,respectively.The SEM showed that PCL/PLA composite was a semi-compatible system.PCL particles could be evenly dispersed in the PLA at 20% or 30% by weight PCL content,and the particle size was very small.DSC results showed a decline in Tg and Tm whereas an increase in Td with the addition of PCL.The addition of PCL could improve the shape memory performance of PLA.The shape memory performance was enhanced with the PCL content increase,but decreased with the tensile strain increase.The best temperature for shape recovery was between 60 and 70 ℃,and the shape memory performance remained 80% after 5 times recycle.展开更多
A polymer blends containing thermoplastic polyurethane（TPU） and poly（lactic acid）（PLA） as a biomedical material were prepared by a process of modifying thermally induced phase separation（MTIPS） and melt blendi...A polymer blends containing thermoplastic polyurethane（TPU） and poly（lactic acid）（PLA） as a biomedical material were prepared by a process of modifying thermally induced phase separation（MTIPS） and melt blending.The influences of composition,shear frequency,and temperature on the rheological behaviors of the blends were investigated by small amplitude oscillatory shear rheology.The results revealed that the addition of TPU into PLA significantly decreased the non-Newtonian index of the blends,and increased the sensitivity of the blends on shear rate,suggesting that optimization of the shear rate and temperature could improve the flowability of the blend melts in the extrusion process.In addition,the results of SEM images revealed that TPU distributed well into PLA matrix and showed good compatibility between the TPU and PLA,which made the blends with good toughness.The primary cytocompatibility of the blends was evaluated using C2C12 cells.The results suggested that the TPU/PLA blends did not affect cell growth,showing no cytotoxicity.In short,the TPU/PLA blends with excellent toughness had potential application as biomedical devices.展开更多
The PLA fiber is one of the green fibers.It is blended with Tencel fibers.The strength of the PLA fiber/Tencel blended yarn is tested.The relationship between the strength and the twist factor and the blended ratio is...The PLA fiber is one of the green fibers.It is blended with Tencel fibers.The strength of the PLA fiber/Tencel blended yarn is tested.The relationship between the strength and the twist factor and the blended ratio is analyzed.The optimum blended ratio of the blended yarn is determined.展开更多
文摘采用同轴静电纺丝技术制备聚乳酸(PLA)-聚己内酯(PCL)核-壳结构复合纤维.利用扫描电子显微镜(SEM)观察纺丝电压、收集距离和核层-壳层溶液推进速度对PLA-PCL核-壳结构复合纤维形貌的影响.通过透射扫描电子显微镜(TEM)分析核层-壳层溶液推进速度对PLA-PCL核-壳结构形成的影响.研究结果表明:当核-壳溶液推进速度为0.1-0.2和0.1-0.3 m L/h时形成了清晰的核-壳结构;随着壳层溶液推进速度加快,PLA-PCL复合纤维核层含量降低,增加纺丝电压能够有效地降低复合纤维平均直径,而增大收集距离使复合纤维平均直径先降低后增加.
文摘通过开环聚合法自主合成聚乳酸聚己内酯（PDLLA‐PCL‐PDLLA ）嵌段聚合物材料，并将其作为聚乳酸／聚己内酯（PLA／PCL）共混体系中两亲性增容剂。通过利用1 H‐NMR、FT‐IR、DMA、FE‐SEM和万能力学实验机对共混材料进行了性能测试，探索增容剂添加量对PLA／PCL共混材料结构和力学性能方面的影响规律。结果表明：随着增容剂PDLLA‐PCL‐PDLLA添加量的提高，在对PLA／PCL共混材料强度影响不大的前提下，断裂伸长率由6．35％提高至15．44％，弹性模量从1782．63 M Pa降到了1471．76 M Pa；共混形貌显示，PCL 在 PDLLA‐PCL‐PDLLA添加量到7％时，在基体PLA中分布均匀。
基金National Natural Science Foundations of China(No.30970714,No.51103092)Natural Science Foundation of Jiangsu Province,China(No.BK2012634)+1 种基金College Natural Science Research Project of Jiangsu Province,China(No.12KJA430003)Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The mechanical properties and water solubility of electrospinning SF films limit their use as biomaterials. In order to develop a tissue engineering biomaterial with both satisfying biological properties and sufficient biomechanical properties,blended films composed of silk fibroin( SF) and poly( ε-caprolactone)( PCL) were fabricated by electrospinning in this study. Scanning electron microscope( SEM), X-ray diffraction( XRD),thermal analysis,Fourier transform-infrared( FT-IR),Raman spectra,mechanical testing,and water solubility were used to characterize the morphological, structural and mechanical properties of the blended electrospinning films. Results showed that the diameter of the blended fiber was distributed between 600 and1000 nm,and the fiber diameter increased as the PCL content increased. There is no obvious phase separation due to the similarity and intermiscibility,as well as the interactions( mainly hydrogen bonds), between the two polymers. Meanwhile, the secondary structures of SF changed from random coils and Silk I to Silk II because of the interactions between SF and PCL. For this reason,the tensile strength and elongation at break of the electrospinning films improved significantly,and the water solubility decreased. In conclusion,the blended electrospinning films fabricated in this study showed satisfying mechanical properties and water insolubilities,and they may be promising biomaterials for applications in tissue engineering for blood vessels,nerve conduits,tendons,ligaments and other tissues.
基金National Natural Science Foundation of China(No.51303085)Prospective Joint Research Project of Jiangsu Province,China(No.BY2015047-14)
文摘Poly(lactic acid)(PLA) was blended with various polycaprolactone(PCL) components through the melt blending process for toughening modification on PLA.The tensile testing,scanning electron microscope(SEM) and differential scanning calorimetry(DSC) were implemented to analyze mechanical properties,disperse morphology,thermal properties and compatibility of composite materials,respectively.The shape memory performance of PCL/PLA composites was also investigated.The results showed that the elongation at break of composites increased by 10 and 15 times than pure PLA with adding 20% and30% by weight of PCL,and the yield strength retention rates were77% and 67%,respectively.The SEM showed that PCL/PLA composite was a semi-compatible system.PCL particles could be evenly dispersed in the PLA at 20% or 30% by weight PCL content,and the particle size was very small.DSC results showed a decline in Tg and Tm whereas an increase in Td with the addition of PCL.The addition of PCL could improve the shape memory performance of PLA.The shape memory performance was enhanced with the PCL content increase,but decreased with the tensile strain increase.The best temperature for shape recovery was between 60 and 70 ℃,and the shape memory performance remained 80% after 5 times recycle.
基金Funded by the Major State Basic Research Development Program of China(973 Program)(No.2012CB933600)the National Natural Science Foundation of China(Nos.81271705 and 83171383)the Major Program of Natural Science Foundation of Shanghai,China(No.12JC1416302)
文摘A polymer blends containing thermoplastic polyurethane（TPU） and poly（lactic acid）（PLA） as a biomedical material were prepared by a process of modifying thermally induced phase separation（MTIPS） and melt blending.The influences of composition,shear frequency,and temperature on the rheological behaviors of the blends were investigated by small amplitude oscillatory shear rheology.The results revealed that the addition of TPU into PLA significantly decreased the non-Newtonian index of the blends,and increased the sensitivity of the blends on shear rate,suggesting that optimization of the shear rate and temperature could improve the flowability of the blend melts in the extrusion process.In addition,the results of SEM images revealed that TPU distributed well into PLA matrix and showed good compatibility between the TPU and PLA,which made the blends with good toughness.The primary cytocompatibility of the blends was evaluated using C2C12 cells.The results suggested that the TPU/PLA blends did not affect cell growth,showing no cytotoxicity.In short,the TPU/PLA blends with excellent toughness had potential application as biomedical devices.
文摘The PLA fiber is one of the green fibers.It is blended with Tencel fibers.The strength of the PLA fiber/Tencel blended yarn is tested.The relationship between the strength and the twist factor and the blended ratio is analyzed.The optimum blended ratio of the blended yarn is determined.
