【作者】 吴珺玥；

【导师】 李晓林；

【作者基本信息】 北京化工大学 ， 材料加工工程， 2009， 硕士

【摘要】 碳纳米管具有独特的物理性能,是一种具有纳米直径的管状碳纤维,它具有超强的强度和韧性以及优异的导电性能。与聚合物复合可改进聚合物的力学性能、电学性能及电磁屏蔽性能,具有广泛的应用前景。本论文在对热固性的生物弹性体—聚(丙三醇-癸二酸-柠檬酸)酯(PGSC)的制备研究基础上,以PGSC为基体,碳纳米管(MWNTs)为增强体,通过不同的方法制备了MWNTs/PGSC复合材料,研究了MWNTs在基体中的分散状况和复合材料的力学性能,探讨了固化时间、MWNTs的添加量对复合材料的结构与性能的影响,并对复合材料进行了初步的细胞毒性评价。本论文的主要研究内容和结果如下:(1)采用熔融共混、研磨分散的方法制备了碳纳米管含量为1.5wt%的MWNTs/PGSC复合材料。研磨分散法能使MWNTs更好的分散在基体中,减少碳纳米管的在复合材料中的团聚现象。通过熔融共混法制得的复合材料,拉伸强度和弹性模量比纯基体材料分别提高了40.0%和15.4%;而利用研磨分散法将熔融共混后的产物进行研磨所制得的复合材料,拉伸强度和弹性模量比基体材料提高了70.9%、19.6%。(2)利用研磨分散法制备了不同固化时间的复合材料,当MWNTs的添加量为1.5wt%时,随着固化时间的延长,MWNTs/PGSC复合材料的拉伸强度和弹性模量逐渐增加,断裂伸长率逐渐降低。当固化时间为18h时,复合材料的拉伸强度、弹性模量较固化时间为12h时分别提高了51.5%,111.8%。复合材料的凝胶含量随固化时间的延长而增大。(3)利用研磨分散法制备了不同碳纳米管含量(0～3.0wt%)的复合材料,当固化时间为20h时,随着MWNTs添加量的增大,碳纳米管在基体中的分散程度逐渐提高,MWNTs/PGSC复合材料的拉伸强度和弹性模量逐渐增大。当MWNTs的添加量为3.0wt%时,碳纳米管在基体中的分散情况最佳,复合材料的拉伸强度、弹性模量较PGSC基体分别提高了58.5%、34.0%。(4)对不同碳纳米管含量(0～3.0wt%)的复合材料进行体外降解测试,降解46天后,纯PGSC失重率可达87.1%,而MWNTs含量为3.0wt%的复合材料,失重率仅为41.4%。加入碳纳米管,能明显降低PGSC的体外降解速率,可以通过调节碳纳米管的添加量控制复合材料的降解速率。(5)细胞毒性试验证明,纯PGSC弹性体的细胞相容性较差,细胞毒性试验评级结果均在2级以下,不能达到医用要求,而MWNTs/PGSC复合材料的细胞毒性评级结果为0-1级,当MWNTs含量大于0.5wt%时,复合材料细胞毒性评级均达到0级,具有良好的细胞相容性。更多还原

【Abstract】 Carbon nanotubes is a kind of carbon fiber tube in nano-diameter, which has unique physical properties, superior strength and toughness as well as excellent conductive properties. Carbon nanotubes are considered as ideal polymers modifier to improve mechanical properties, electrical properties and electromagnetic shielding performance, which has been widely applied in many fields.In this thesis, based on the preparation and research of biological thermoset elastomers-poly(glycerol-sebacic acid-citric acid)ester (PGSC), the MWNTs / PGSC composites were prepared by various methods using MWNTs as the reinforcing filler and PGSC as the matrix. The dispersion of MWNTs in the matrix and the mechanical properties of composites were studied here. The effects of molding time and MWNTs’ content on composites structure and properties were investigated as well. Besides, the elementary evaluation tests of cell toxicity were carried out.The main research contents and results were shown as follows:(1) MWNTs/PGSC composites with MWNTs content 1.5wt% were fabricated by melt blending and grinding dispersed methods. Comparing to other method, MWNTs could be better dispersed in the matrix by grinding method owing to the reducing of MWNTs agglomeration in composites. When comparing composites prepared by melt blending method with pure PGSC, the tensile strength and elastic modulus of the composites could be increased by 40.0% and 15.4% respectively. Moreover, it was found that the tensile strength and elastic modulus of the composites could be increased by 70.9% and 19.6% when applying grinding method after the melt blending process.(2) The MWNTs/PGSC composites prepared by grinding method with different molding time have been studied in this work. With the fixing 1.5wt% of MWNTs, the tensile strength and elastic modulus increased gradually as molding time increased, but the elongation at break decreased at the same time. When the molding time was set as 18h, the tensile strength and elastic modulus of composites increased by 51.5% and 111.8% respectively, comparing to those from 12h. It can be said that the gel content of composites grows with the delaying of the molding time.(3) MWNTs/PGSC composites with different MWNTs contents from 0 to 3.0wt% were fabricated by grinding dispersed methods. When the molding time was fixed as 20h, as the adding amount of MWNTs increased, the tensile strength and elastic modulus of composites increased gradually due to the improving of the dispersion of MWNTs in the matrix. When the content of MWNTs was 3.0wt%, the composites showed the best dispersion of MWNTs in PGSC as well as the most optimum mechanical properties. The tensile strength and elastic modulus increased by 58.5% and 34.0% respectively.(4) The in vitro degradation of MWNTs/PGSC composites with different MWNTs contents from 0 to 3.0wt% were also investigated. After 46 day degradation, the mass loss of PGSC is up to 87.1%, but the composites contented 3.0wt% MWNTs only reached 41.4%. In vitro degradation rate of PGSC can be significantly reduced by adding carbon nanotubes. And the degradation rate of composites can be controlled by adjusting the volume of carbon nanotubes.(5) Cytotoxicity test proved that the cell relative growth rates of pure PGSC was low and the PGSC couldn’t meet the medical requirements. However, MWNTs/PGSC composites had a good cytocompatibility. There was no significant toxicity on cell’s growth when the MWNTs content was more than 0.5wt%.更多还原