Preparation And Properties Of Carbon Nanotube/ Montmorillonite/ Polymer Nanocomposites

Polymer nanocomposite is regarded as one of the most promising materials in the modern century. In order to fully exploit the potential of nanofillers, a lot of fruitful researches have been done. Inspired by the concept of alloy, researchers attempt to construct polymer nanocomposites with mixed nanofillers in order to pursuit the significant synergic enhancement of the performance of polymer nanocomposites. The polymer nanocomposites constructed by the clay/carbon nanotube(CNT) nanohybrids in this work also belong to this research category. The goal of this work is to develop an economic way for preparing the high-performanced polymer nanocomposites.In this work, we prepared the clay/carbon nanotube nanohybrids(SCH) by ethylenediamine grafted single-walled carbon nanotubes(N+-SWNT) with positive charge surface and the nanolayers of exfoliated Na+-MMT(CNLs) with negative charge surface through the long-range electrostatic interaction. The SCH were applied to the preparation of polyvinyl alcohol(PVA) nanocomposite films and Nylon 6 nanocomposites so as to investigate the synergic effect between N+-SWNT and CNLs in improving the properties of polymer nanocomposites. SEM and TEM found that SCH could disperse uniformly in polymer matrix and form good interfacial adhesion. More importantly, SCH could maintain its nano-heterostructure in polymer matrix, which brought about the synergic effect of N+-SWNT and CNLs in improving the mechanical properties(strength and modulus) and thermal properties(thermal stability and thermal conductivity) of PVA and Nylon 6, and even showed “1+1>2” synergic effect in improving the mechanical properties as confirmed by the mechanical test, DSC, thermal conductivity, TGA test and so on. When the SCH content was 5.0 wt%, the tensile strength and Young's modulus of the PVA/SCH nanocomposites were 139.5 MPa and 2.77 GPa respectively, increased by 112 % and 131 %. Compared to the pure PVA, the TE-III and the thermal residual weight of PVA/SCH nanocomposites were increased by 20 °C and 9 wt%. When the SCH content was 3.0 wt%, the tensile strength and Young's modulus of the Nylon 6/SCH nanocomposites were 81.4 MPa and 2.145 GPa respectively, increased by 105 % and 170 %. Compared to the pure Nylon 6, the thermal conductivity of Nylon 6/SCH nanocomposites was increased by 36 %. Compared with the clay/CNT nanohybrid materials constructed by the chemical vapor deposition(CVD) method reported by the literature, not only the SCH had the similar effect in improving the mechanical properties and thermal stability, but also the construction method had the advantages of low cost, simpleness and controllability.