Preparation and Properties of Polylactic Acid (PLA)/Nano-SiO2 Composite Master Batch with Good Thermal Properties

In order to improve the thermal properties of polylactic acid( PLA) master batch,the nano-SiO2 was applied to mixing with PLA. The structure and thermal properties of the composite master batches were studied. The results showed that the nano-SiO2 modified by 3% coupling agent KH-570 could be dispersed evenly in PLA in small scale. The thermal decomposition temperature of composite master batches increased by 6. 20-10. 80 ℃, the glass transition temperature increased by 0. 22-5. 16 ℃,and the heat enthalpy at the glass transition temperature increased by 0. 574-2. 437 J /g,compared with pure PLA. The composite master batch possessed superior thermal stability and heat resistance.     

PLA纤维纱线浆纱工艺研究

针对PLA纤维纱线的特点,选用马铃薯变性淀粉K5为主浆料,PVA、聚丙烯酸为辅,蜡片为助剂,制定了3种经纱上浆配方,对其浆液性能、浆膜性能和浆纱性能及其他指标进行测试。对比分析,得出了PLA纤维纱线上浆的最佳工艺路线。用马铃薯变性淀粉K5替代PVA ,既满足了PL A纤维纱线上浆要求,也减少了环境污染。     

Preparation Process and Mechanical Properties of PLA/PCL Intravascular Stent

A hand-made biodegradable intravascular stent with zig- zag structure has been developed, which made from polylactic acid （ PLA ） braided thread and poly-eaprolactone （ PCL ） tube. This paper showed the preparation process of the PLA braded thread and stent, and discussed the heat setting process of the stents. The sixteen groups of stents were made for the heat setting experiments, discussing two factors on four levels. Radial compression behavior of stents was tested by plate compression method. The result showed that both the heat setting temperature and time had significant effects on stent compression strength. The compression recovery rate was mainly affected by heat setting temperature. The optimized heat setting condition should be 90-100℃ for 45 rain.     

Effect of PLA Knitted Structure on the Mechanical Properties of Composite Vascular Scaffold

A new entire biodegradable scaffold has been developed which does not require precelluiarization before transplantation. This new kind of vascular scaffold prototype made from porous poly- e-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.     

纳米蒙脱土/PAE/PLA复合材料制备及性能研究

聚乳酸(PLA)材料极易脆性断裂,为了提高其韧性,采用片状纳米级蒙脱土颗粒与医用级聚酰胺弹性体(PAE)对PLA进行共混改性。测试并分析了不同混合比例条件下复合材料的力学性能,并通过SEM、DSC对材料的性能进行表征。结果表明：所得到的三元复合材料具有优良的力学性能,其中当纳米蒙脱土含量为2.5%、PAE含量为10%、PLA含量为87.5%时,材料的韧性更好,综合力学性能最佳。纳米蒙脱土及PAE的含量对体系的分散形态均有影响：当纳米蒙脱土含量为2.5%时,其在聚合物中能够均匀分散,含量继续增加时易出现团聚现象;当纳米蒙脱土含量为2.5%、PAE含量为20%时,相与相之间界面较为模糊,形成了一定厚度的界面过渡层。纳米蒙脱土被引入聚合物体系后起到成核作用,提高了PLA的结晶度,从而有利于复合材料力学性能的提高。     

宏阔的党史军史:战斗文化建设的生动教材

以战斗文化建设为核心,以党史军史教育为切入点,指出宏阔的党史军史是战斗文化建设的生动教材,并从四个方面深入阐释了党史军史与我军战斗文化建设的关系,认为党史军史教育,有助于夯实战斗文化的思想根基,有助于催生战斗文化的战斗精神,有助于推进战斗文化的传承发展,有助于增强战斗文化的建设活力。新形势下的战斗文化建设,加强党史军史教育,才有坚实深厚的根基。     

可编程逻辑阵列嵌入自测试设计

本文提出的设计方案,以极低的附加硬件资源覆盖了包括附加电路在内的所有单重固定故障、交叉点故障、邻线桥接故障和几乎所有的多重故障。同现今通行的设计方案相比,具有下列明显优点:1) 极低的附加硬件资源;2) 极高的故障被测度;3) 对可编程逻辑阵列的正常操作没有影响;4) 减少了测试延迟;5) 故障检测异常简单。     

差热分析在聚乳酸纤维染色中的应用

应用差热分析研究聚乳酸纤维染色前后玻璃化温度及熔融温度变化,通过用4种分散染料对针织聚乳酸纤维面料染色后的DSC分析发现,染色性能不仅与染料结构及加工性能有关,还与纤维结晶度有关;染料染色改变了纤维结晶度,对染色温度的选择具有一定的影响.     

学习贯彻新《纲要》推动基层建设全面发展

学习贯彻新《军队基层建设纲要》，对于不断推动部队基层建设又好又快发展，努力开创基层建设新局面具有重要意义。抓好新《纲要》的学习贯彻，需在掌握工作遵循上下功夫，在严格按纲抓建上下功夫，在打牢建设基础上下功夫，在依法开展工作上下功夫，努力在新的起点上推进基层建设全面进步、协调发展、整体提高，打牢夯实履行新世纪新阶段我军历史使命的坚实基础。     

Research on the Sizing Performance of Starch Grafted Poly-hydroxy Alkyl-acid Esters

Starch grafted poly-hydroxy alkyl-acid esters were prepared via graft polymerization.Different characteristics of grafted starches were tested such as viscosity,viscosity stability,adhesion as well as properties of sized yarns.Sizing performance was analyzed from the aspect of physical and chemical reactions between polymer molecules.It shows that starch grafted poly-hydroxy alkyl-acid esters have excellent sizing performance and could absolutely be used as sizes for polyester-cotton yarns.