【作者】 宋亮；

【导师】 邱兆斌；

【作者基本信息】 北京化工大学 ， 材料加工工程， 2009， 硕士

【摘要】 近年来,碳纳米管凭借其优异的物理性能受到了人们的广泛关注,尤其在其作为填充体改性聚合物基体的工作中显示出良好的发展前景,为聚合物高性能和多功能化提供新的途径。本课题以生物降解聚酯聚丁二酸丁二醇酯(PBSU)作为基体,分别通过熔融法和溶液法填充性能优异的碳纳米管(CNTs)与其复合并对其结构与性能之间的关系进行深入而细致的研究,以达到改善其性能,进一步拓宽其应用领域的目的。主要工作如下:1.利用Brabender双螺杆密炼机制备了PBSU和质量含量为2%的羧化后的多壁碳纳米管(f-MWNTs)的复合材料。采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、差示扫描量热仪(DSC)、热台偏光显微镜(POM)和热失重(TG)分别研究了f-MWNTs在基体中的分散性以及复合材料的非等温结晶行为、结晶形态和热稳定性。DSC和POM研究结果发现f-MWNTs的加入起到了较强的成核剂的作用,提高了结晶温度,细化了晶体粒度,有力的促进了PBSU的结晶过程。采用Avrami和Ozawa联立的莫志深法能够较好的描述本体系的非等温结晶过程。采用不同的升温速率和调制DSC技术(TMDSC)分析研究了纯PBSU和复合材料的复杂的熔融行为。TG研究结果表明f-MWNTs的加入一定程度上提高了PBSU的热稳定性。2.采用溶液混合、超声处理的方法制备了一系列不同低填充含量MWNTs的PBSU/MWNTs复合材料并采用SEM、TEM、DSC、POM、广角X光衍射(WAXD)、拉伸测试(tensile test)、动态力学测试(DMA)等多种手段进行表征。SEM和TEM结果表明,f-MWNTs在基体中能够均一的分散,而未修饰的MWNTs(P-MWNTs)由于较大的表面能和自身范德华力作用呈现一定程度的团聚。DSC、POM和WAXD研究结果表明,少量f-MWNTs的加入明显提高了PBSU的结晶速率而其结晶机理和结晶结构没有发生改变。拉伸测试结果表明,f-MWNTs的加入在保证基体断裂伸长率的情况下能够适当的提高PBSU基体的拉伸模量。DMA研究发现,在整个测试温度范围内f-MWNTs能够显著的提高PBSU基体的储能模量,而其内耗角的峰位置却没有发生明显的变化。初步研究了纯PBSU及复合材料在37℃的碱性溶液环境下的水解过程。研究结果表明,PBSU及其复合材料整体上呈现为一步降解过程,降解速率先快后缓,并且复合材料的降解速率明显高于纯PBSU。更多还原

【Abstract】 In this work,nanocomposites based on poly(butylene succinate)(PBSU) and multi-walled carbon nanotubes(MWNTs) were prepared through both melt and solution compounding methods.The relation between structure and property were studied in detail so as to improve its property and further expand its application areas.The main work is as follows:1.PBSU/functional multi-walled carbon nanotubes(f-MWNTs) was prepared via melt compounding method using a Brabender twin-screw mixer. The dispersion of f-MWNTs in the PBSU matrix was first studied by scanning electron microscopy(SEM) and transmission electron microscopy(TEM). Nonisothermal crystallization behavior,crystallization morphology and thermal stability were also studied by differential scanning calorimeter(DSC), hot stage polarizing microscope(POM) and thermal gravimetric(TG).POM result shows an notable smaller spherulite with the addition of f-MWNTs.The subsequent melting behavior after the nonisothermal crystallization was studied by DSC and modulated DSC(TMDSC) as well.The TG results indicate an improvement in thermal stability of PBSU in the nanocomposite. 2.PBSU/MWNTs nanocomposites at low MWNTs loadings were prepared successfully through solution casting method.SEM and TEM results observed a homogeneous dispersion of f-MWNTs throughout the PBSU matrix while some agglomeration was also found for the unmodified MWNTs. The crystallization rate of PBSU is markedly enhanced while the crystallization mechanism remains almost unchanged in the nanocomposites. POM result reveals an obvious smaller spherulite for the nanocomposites while the crystal structure of PBSU in the nanocomposites is not changed as evidenced by the WAXD result.Tensile test result shows a moderate increase in tensile modulus while a little decrease in elongation at break.Dynamic mechanical analysis(DMA) shows a significant improvement in the storage modulus as compared to that of neat PBSU.The hydrolytic degradation process of PBSU and its nanocomposites at 37℃show one step degradation. More interesting,the hydrolytic degradation rate is faster in the nanocomposites than that in neat PBSU.更多还原