聚乳酸/聚氨酯/聚乙烯吡咯烷酮降解材料的制备与性能

采用熔融共混法制备了聚乳酸(PLA)/聚氨酯(PU)/聚乙烯吡咯烷酮(PVP)复合材料,利用红外光谱(FTIR)、扫描电镜(SEM)、偏光显微镜和降解性能测试对其结构和性质进行了表征分析.结果表明:PU和PVP在基体PLA中可均匀分散且有效结合,该复合材料的拉伸强度可达69.18 MPa,断裂伸长率可提高1倍.降解实验表明,复合材料在不同介质中均呈现出随降解时间的延长,质量不断降低的趋势.     

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.     

聚己二酸乙二酯的合成及其与聚乳酸的共混研究

分别采用对甲苯磺酸与钛酸丁酯两种催化剂,通过缩聚反应制备了脂肪族聚酯——聚己二酸乙二酯(PEA)。研究了催化剂的种类和用量对PEA分子量的影响,考察了PEA样品对聚乳酸力学性能的改性效果。结果表明,两种催化剂用量相同时,钛酸丁酯的催化效率高;用钛酸丁酯做催化剂时,最佳用量为酸的摩尔量的1‰;用对甲苯磺酸做催化剂时,最佳用量为酸的摩尔量的5‰;不同分子量的PEA对PLA改性效果不同,采用较高分子量的PEA与聚乳酸(PLA)共混,在PEA含量达到10%之后,可以取得较好的改性效果。     

聚乳酸／双亲性葡聚糖中空纳米囊泡包载亲水性药物及释放

亲水性药物包载是缓释纳米微粒制备的难点，通过共透析胆固醇改性葡聚糖和聚乳酸得到表面多糖修饰的中空纳米囊泡，在透析过程中以氯化钆溶液代替水相，所得纳米囊通过透射电子显微镜观察和热失重分析测试，证明氯化钆可包载于中空纳米囊泡的亲水性内核，且在纳米囊泡壁形成微孔道．将此纳米囊对亲水性药物头孢拉定反透析，药物通过微孔道扩散进入内核得到载药纳米囊．药物释放研究表明，纳米囊泡使亲水性药物持续释放24h以上，具有缓慢释放的特性．     

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.     

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.     

MBS对PLA/GMS吹塑薄膜性能的影响

用熔融共混方法制备聚乳酸/甲基丙烯酸甲酯 丁二烯 苯乙烯三元共聚物/单硬脂酸甘油酯三元共混物及吹塑薄膜, 并研究聚乳酸/甲基丙烯酸甲酯 丁二烯 苯乙烯三元共聚物/单硬脂酸甘油酯三元薄膜的力学性能、 光学性能、 流变性能、 热性能和结晶 性能. 其中, 甲基丙烯酸甲酯 丁二烯 苯乙烯三元共聚物为增韧剂, 单硬脂酸甘油酯为增塑剂. 结果表明： 加入甲基丙烯酸甲酯 丁二烯 苯乙烯三元共聚物可改善聚乳酸/甲基丙烯酸甲酯 丁二烯 苯乙烯三元共聚物/单硬脂酸甘油酯薄膜的力学性能, 并提高聚乳酸的结晶性能.     

聚乳酸/无机纳米粒子复合材料研究进展

 综述了近年来国内外关于聚乳酸/无机纳米粒子复合材料的研究和发展状况。研究表明将聚乳酸与无机纳米粒子通过复合改性,能够明显提高复合材料各方面的性能,从而扩展了聚乳酸的应用范围。聚乳酸/无机纳米复合材料分为两类,一类是层状硅酸盐无机纳米复合材料,另一类是无机纳米刚性粒子,主要包括二氧化硅、二氧化钛、氧化镁、氧化锌等氧化物。介绍了两类复合材料的制备方法,包括原位聚合法、共混法和溶胶凝胶法,阐述了无机纳米粒子的添加对聚乳酸力学性能、热稳定性能、结晶性能、降解性能、流变性能和气体阻隔性能的影响。未来的发展方向是希望通过加入具有一定特性的纳米粒子,制备出特定功能的聚乳酸无机纳米粒子复合材料。     

胶原修饰快速成形PLGA/TCP人工骨支架体外生物相容性研究

探讨经Ⅰ型胶原修饰的快速成型(RP)聚乳酸-羟基乙酸/磷酸三钙(PLGA/TCP)支架的生物相容性,为进一步体内实验提供研究基础.以经Ⅰ型胶原修饰改性的PLGA/TCP支架作为实验组,未经胶原修饰的原始支架作为对照组,检测两组支架材料的亲水性.BMSCs接种两组支架,分别测定细胞黏附率、细胞增殖率.扫描电镜(SEM)观察细胞黏附形态,以检验支架材料的细胞相容性.结果表明胶原改性支架具有较高的亲水性,实验组细胞黏附率在接种4、8和12 h者,明显优于对照组(P<0.05).实验组在培养2、4、6和8 d的细胞增殖率也明显高于对照组(P<0.05).扫描电镜可见骨髓基质细胞在实验组支架上的增殖数量多于对照组.说明Ⅰ型胶原改性的PLGA/TCP支架具有良好的细胞生物相容性,可作为骨组织工程支架应用于骨缺损的修复研究.     

聚乳酸降温膜的研究

用L-丙交酯单体,在催化剂作用下开环聚合,得到聚乳酸,采用己内酯做改性剂,得到复合材料,并制备出聚乳酸基复合膜,聚合物采用核磁(H NMR)进行结构鉴定,利用凝胶色谱仪(GPC)测试聚合物的分子量,采用DSC对薄膜进行结晶度测定.并将该膜应用到加热不燃烧卷烟领域,实验结果表明,聚乳酸用于烟棒具有较好的降温效果.