石墨烯材料增强高分子基复合材料的制备与性能研究

发布时间：2018-07-26 12:43

【摘要】：石墨烯材料具有优异的性能和结构特性,是聚合物基复合材料的理想增强材料,因此本论文分别进行了石墨烯材料增强细菌纤维素(BC)的导电性能和环氧树脂热性能的研究。利用纳米石墨微片(GNPs)进行了提高BC导电性能的研究,制备了GNPs/BC导电复合膜。作为对比还制备了多壁碳纳米管(MWCNT) /BC导电复合膜。首先研究了GNPs和MWCNT在分别含有0.3wt%十二烷基苯磺酸钠、0.3wt%A1100以及不含表面处理剂的无水乙醇溶液中的分散稳定性,结果表明GNPs在纯无水乙醇溶液中的分散稳定性最佳,MWCNT在含有0.3wt%A1100的无水乙醇溶液中分散稳定性最佳。基于上述研究结果,分别通过超声法和浸渍法在GNPs-无水乙醇悬浮液中制备了GNPs/BC导电复合膜,在MWCNT-无水乙醇悬浮液中(含有0.3wt%A1100)制备了MWCNT/BC导电复合膜。场发射扫描电子显微镜(FESEM)分析结果表明,通过有效的物理(超声)和化学方法(表面处理剂)处理后,片状GNPs成功地嵌入到BC纳米纤维网络结构的表层；棒状MWCNT则均匀地插入到BC膜的孔中。利用四探针法测量复合膜的导电率,并测量了复合前后膜的质量变化。结果表明：超声法制备的复合膜的导电率要高于浸渍法；采用超声法制备得到的BC基复合膜,GNPs在基体中的最大填充量为8.7wt%,复合膜的最高导电率达到4.5S/cm; MWCNT在基体中的最大填充量为13.9wt%,复合膜的最高导电率达到1.2S/cm。利用多层氧化石墨烯(MGO)进行了提高环氧树脂热性能的研究。首先利用差示扫描量热法研究了MGO含量(0.5、1、2、3wt%)对环氧树脂固化反应过程的影响,结果表明,随着MGO含量的增加(0.5、1、3wt%),MGO对环氧树脂固化反应初期以及固化后期玻璃化转变的阻碍作用逐渐增强,但是当其含量从1wt%增加到2wt%时,这种阻碍作用变弱。通过原位聚合法制备了不同MGO含量(0.5、1、2、3wt%)的环氧树脂基复合材料,并分别利用广角X射线衍射和FESEM对MGO在环氧树脂基体中的剥离和分散状态进行了分析。结果表明,当MGO含量低于3wt%时,MGO在基体中被良好的剥离并均匀分散,而当MGO的含量达到3wt%时出现了堆垛和团聚。MGO/环氧树脂复合材料的热性能测量结果表明,2wt%MGO为复合材料的最佳含量,在此含量下复合材料具有最高的热稳定性和最大的导热率(较纯树脂基体增大了2.03倍),并且热膨胀系数较也纯树脂基体减小23%,达到最小。
[Abstract]:Graphene is an ideal reinforcement for polymer matrix composites because of its excellent properties and structural properties. Therefore, the electrical conductivity of graphene reinforced bacterial cellulose (BC) and the thermal properties of epoxy resin were studied in this paper. The conductive composite film of GNPs/BC was prepared by using nano-graphite (GNPs) to improve the conductivity of BC. The multiwalled carbon nanotubes (MWCNT) / BC) conductive composite films were also prepared as a comparison. The dispersion stability of GNPs and MWCNT in anhydrous ethanol solution containing 0.3 wt% dodecylbenzene sulfonate, 0.3wt100 and anhydrous ethanol without surface treatment agent was studied. The results show that the dispersion stability of GNPs in pure absolute ethanol solution is the best, and that in anhydrous ethanol solution containing 0.3wt100 is the best. Based on the above results, GNPs/BC conductive composite membranes were prepared by ultrasonic method and impregnation method, respectively, and MWCNT/BC conductive composite membranes were prepared in MWCNT- anhydrous ethanol suspensions (containing 0.3wt100). The field emission scanning electron microscope (FESEM) analysis results show that the sheet GNPs is successfully embedded into the surface layer of BC nanofiber network after effective physical (ultrasonic) and chemical (surface treatment agent) treatment. The rod-shaped MWCNT is uniformly inserted into the pores of the BC film. The conductivity of the composite membrane was measured by four probe method, and the quality change of the film before and after the composite was measured. The results show that the conductivity of the composite membrane prepared by ultrasonic method is higher than that by impregnation method. The maximum filling capacity of the BC-based composite membrane prepared by ultrasonic method is 8.7 wt. the maximum conductivity of the composite membrane is 4.5 S / cm, and the maximum filling amount of MWCNT in the substrate is 13.9 wts. the maximum conductivity of the composite membrane is 1.2 S-1 路cm. The thermal properties of epoxy resin were studied by multilayer graphene oxide (MGO). At first, the effect of MGO content (0.5%) on the curing process of epoxy resin was studied by differential scanning calorimetry (DSC). With the increase of the content of MGO (0.5 wt%), the blocking effect on the glass transition of epoxy resin at the initial and late curing stage was gradually enhanced, but when the content increased from 1wt% to 2wt%, the hindrance became weaker. Epoxy resin matrix composites with different MGO content (0.5 ~ 1U ~ (-2) W ~ (-1) were prepared by in-situ polymerization. The peeling and dispersion states of MGO in epoxy resin matrix were analyzed by wide angle X-ray diffraction (WAXD) and FESEM, respectively. The results show that when the content of MGO is lower than 3 wt%, it is well peeled off and uniformly dispersed in the matrix. However, when the content of MGO reached 3wt%, the thermal properties of the composite were measured by stacking and agglomeration. The composites have the highest thermal stability and maximum thermal conductivity (2.03 times higher than the pure resin matrix), and the thermal expansion coefficient is 23% less than that of the pure resin matrix.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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