Synthesis, mechanical properties and microstructure of carbon nanotube polymer composites

• Main Author: Li, Qianqian
• Published: University of Edinburgh 2006
• Subjects: 668.9
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653878

A commercial block copolymer (BC) was first introduced as a dispersing agent to disperse CNTs homogenously in an elastomeric epoxy resin. Single wall CNTs (SWNTs) and multiwall CNTs (MWNTs) were both used to reinforce this epoxy resin. By adding the BC, mechanical properties of CNT/epoxy resin composites were increased dramatically compared to CNT composites without BC. Optical microscopy and scanning electron microscopy were conducted to study the microstructure of CNT/copolymer/epoxy resin composites. It has been confirmed that by using BC, CNTs were dispersed more homogenously in the epoxy resin matrix. Furthermore, improved mechanical properties of composites were achieved by using small amount of BC. The effects of different preparation procedures and different concentrations of materials were also studied. The optimum ultrasonic time and power were decided after trying different options. Ethanol was chosen as a solvent in order to help improving the dispersion. Thus, the optimum proportions of CNT/BC and CNT/epoxy resin were determined for further systematic studies. Finally, SWNT composites and MWNT composites were produced by adding the same mass weight CNTs and by adding the same surface area CNTs. In both cases, SWNT composites presented the best mechanical properties compared to MWNT composites. By adding the same mass weight, the MWNT composites with smaller diameter were stronger because of overall higher surface area; while by adding amounts with the same total surface area, the results were opposite.