将竹纤维(BF)与聚己内酯(PCL)、聚乳酸(PLA)熔融共混,通过模压工艺制备了PCL/PLA/BF增强复合材料。研究了BF质量分数对该复合材料力学性能、热稳定性以及熔融结晶行为的影响。结果表明:随着BF质量分数的增加,PCL/PLA/BF复合材料的冲击...将竹纤维(BF)与聚己内酯(PCL)、聚乳酸(PLA)熔融共混,通过模压工艺制备了PCL/PLA/BF增强复合材料。研究了BF质量分数对该复合材料力学性能、热稳定性以及熔融结晶行为的影响。结果表明:随着BF质量分数的增加,PCL/PLA/BF复合材料的冲击强度、拉伸强度和断裂伸长率均先增大后减小,并均在BF质量分数为40%时达到最大值,分别为11.26 k J/m2、12.68 MPa和5.2%;BF质量分数对PCL/PLA/BF复合材料的热稳定性无明显影响;BF的加入使得复合材料中PCL、PLA共混物的玻璃化转变温度降低,但不同BF质量分数的复合材料玻璃化转变温度变化不大;BF的加入使得复合材料结晶温度小幅提升,但结晶峰强度随着BF质量分数的增加而逐渐减弱。展开更多
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
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 new entire biodegradable scaffold has been developed which does not require precellularization before transplantation.This new kind of vascular scaffold prototype made from porous poly-ε-caprolactone( PCL) membrane...A new entire biodegradable scaffold has been developed which does not require precellularization before transplantation.This new kind of vascular scaffold prototype made from porous poly-ε-caprolactone( PCL) membrane to provide three-dimensional environment for cell growth, and embedded with weft-knitted polylactic acid( PLA) fabric to support mechanics.The aim of this paper is to study the variation tendency of mechanical properties with the fabric spacing changing.The basic geometrical parameters were measured to characterize properties of the samples.The tensile and compressive elastic recovery of the samples were tested by the universal mechanical tester and radial compression apparatus,respectively.Both tensile and compressive properties enhanced when reducing the fabric spacing of the composite vascular scaffold.展开更多
Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is...Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.展开更多
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。
文摘将竹纤维(BF)与聚己内酯(PCL)、聚乳酸(PLA)熔融共混,通过模压工艺制备了PCL/PLA/BF增强复合材料。研究了BF质量分数对该复合材料力学性能、热稳定性以及熔融结晶行为的影响。结果表明:随着BF质量分数的增加,PCL/PLA/BF复合材料的冲击强度、拉伸强度和断裂伸长率均先增大后减小,并均在BF质量分数为40%时达到最大值,分别为11.26 k J/m2、12.68 MPa和5.2%;BF质量分数对PCL/PLA/BF复合材料的热稳定性无明显影响;BF的加入使得复合材料中PCL、PLA共混物的玻璃化转变温度降低,但不同BF质量分数的复合材料玻璃化转变温度变化不大;BF的加入使得复合材料结晶温度小幅提升,但结晶峰强度随着BF质量分数的增加而逐渐减弱。
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.
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the Fundamental Research Funds for the Central Universities,China，National Natural Science Foundation of China，"111 Project" Biomedical Textile Materials Science and Technology,China，the Donghua University Innovation Fund of Graduate Project,China
文摘A new entire biodegradable scaffold has been developed which does not require precellularization before transplantation.This new kind of vascular scaffold prototype made from porous poly-ε-caprolactone( PCL) membrane to provide three-dimensional environment for cell growth, and embedded with weft-knitted polylactic acid( PLA) fabric to support mechanics.The aim of this paper is to study the variation tendency of mechanical properties with the fabric spacing changing.The basic geometrical parameters were measured to characterize properties of the samples.The tensile and compressive elastic recovery of the samples were tested by the universal mechanical tester and radial compression apparatus,respectively.Both tensile and compressive properties enhanced when reducing the fabric spacing of the composite vascular scaffold.
文摘Currently, animal and clinical research on biomaterials, such as surgical sutures, are mainly performed by removing them from the experiment targets and observing them by microscopy. However, traditional microscopy is not able to observe the internal structure, and there is a risk of sacrificing animals to remove the suture and damaging the materials. Therefore, we introduced optical coherence tomography (OCT) to observe and evaluate four different kinds of surgical sutures in vivo (monofilament absorbable and nonabsorbable sutures and braided absorbable and nonabsorbable sutures). As a result, while the monofilament nonabsorbable sutures showed almost no change over time, the absorbable sutures had color fading and it was also confirmed that the internal structure became chaotic due to decomposition, which improved the OCT signal intensity. For the braided sutures, both absorbable and nonabsorbable, we found that the reflection signal improved from week 0 because blood got among the filaments of sutures and dried during recovery which increased OCT signal from week 0 to week 1. We also confirmed that the braided sutures untwisted over time. All four kinds of sutures were pulled due to the movement of rats during recovery. It is expected that OCT technology will be of great help in in vivo experiments on biomaterials such as sutures.
