Preparation Of Polyarylene Ether/carbon Nanotubes Gradient Composite Films

With the development of Science and technology, the demand of material with perfect properties was more and more urgent; in the most ways composition of polymers with carbon nanotubes becomes a useful method to produce high performance materials. Nanoscience and technology provides an effective way in modification of polymers by compounding, especially carbon nanotubes(CNTs), which can be considered as a material with quasi-1D nano structures, have attracted much attention for their special structures and unique properties. Such carbon nanotube filled polymer composites can attribute to the improvement of processing of polymer matrix, and in this process the novel properties, such as electrical and optical performance, were obtained.Among the polymers, poly(arylene ether)s are a general class of high performance engineering plastics which include poly(phenylene oxide)s, poly(ether imide)s, poly(ether sulfone)s and poly(ether ketone)s. Such series of polymers can exhibit extremely outstanding thermal resistance for (1) meta-phenyl links, which attribute to the polarity and thermal resistance and (2) Oxygen ether bond or Sulphur ether bond, which is flexible and also has excellent thermal resistance. PAEs as a semicrystalline thermoplastic resin with excellent mechanical properties and temperature resistance have been applied in electronical engineering, electronics, appliances, and consumer goods. In order to cope with some limitations of PAEs and hence to spread their application sectors, carbon nanotubes can be added to this series of polymers, leading to a composite system, which should, at best, combine the advantages of the two phases it is composed of. Polyarylene ether nitriles(PEN), which is a class of PAE, doped with carbon nanotube can form a composite film, which may fulfill some of these needs. Therefore, a PEN/CNTs gradient composite films were prepared through the composition of carbon nanotubes with the high performance engineering plastic——PEN. Such gradient composite films offer the advantages of high modulus and Tg, and exhibit some other novel properties such as electrical and optical property as well. The gradient composite films still maintained excellent mechanical property compared to that of the pure PEN. The gradient distribution of carbon nanotubes in the matrix at best combined the excellent mechanical properties with other novel properties of the two phases. It supposed that the mechanical property would be improved rapidly if the carbon nanotubes could disperse in matrix uniformly after some certain treatment. As far as the thermal property is concerned, both the glass transition(Tg) and 5% weight loss temperature of the various systems were compared by DSC and TGA. And we noticed that the thermal property of PEN, i.e. Tg and 5% weight loss temperature, were not varied by filling of carbon nanotubes. There is only a little increment on Tg with the weight fraction of carbon nanotubes, which is in agreement with the study of Tg of polymer/CNTs composite materials before. We found that the 5% weigh loss temperature of the PEN film was not varied after introduction of the carbon nanotubes, which proved that the thermal stability of the PEN film was not destroyed after doping the carbon nanotubes. Furthermore, we use some instruments and measurements to testify the gradient distribution of carbon nanotubes in the matrix of PEN, such as insulation ohmmeter, UV/Vis, Contact angle, XPS, etc. And excitingly, the results were in accordance with what we expected. Above all, we obtained a novel gradient composite film prepared through doping carbon nanotubes into PEN under certain preparation condition. Such gradient composite film, which can be deemed to a functional composite film, could be applied in the electronic engineering industry, elecronics and aerospace fields for its excellent mechanical properties, thermal stability and novel electrical and optical properties.