Rapid-manufacturing of micro-structured devices based on MWCNTs/PP composites by using hot embossing replication process

摘要

Carbon nanotubes have attracted the fancy of many scientists since their first discovery in 1991. Their small dimensions, strength and remarkable physical properties make them a very unique material with a whole range of promising applications. The most important application of carbon nanotubes based on their important mechanical properties will be as reinforcements in composite materials, especially nanotube-filled polymer composites are an obvious materials application area. In this work, the micro-structured devices in range of micro meter have been manufactured based on polymer/carbon nanotubes composites by using hot embossing replication process. Firstly, the carbon nanotubes with different loading rate (0.1, 1 and 10%) have been mixed with polypropylene (PP) in molten state to obtain the composite, the rheological properties of MWCNTs/PP composites with different CNT loading ratios were investigated by means of rheometer with a cone-and-plate geometry, the improvement of dispersion of the CNT particles in polypropylene matrix were observed by scanning electronic microscopy. Afterwards, the obtained composite were granulated in particles and used in hot embossing process to realize the replication of micro structured; in this step, a Al mould with micro-motif on surface obtain by machining with computer numerical control machine tools has been used. Finally, the micro-structured motifs on the mould have been successfully transferred with the details on the MWCNTs/PP substrate under the embossing pressure.