Читать книгу Polymer Nanocomposite Materials - Группа авторов - Страница 24

Double-screw extrusion disperses nanofillers in thermoplastic matrix by huge shear force generated by high speed rotation of double-screw at high temperature [113, 114]. This method has been widely used in industry due to the advantages of solvent-free and environment-friendly technology. With this method, the fillers can be dispersed into the polymer in a high content way to achieve the well-controlled performance, and applied to different sizes of nanoparticles, such as graphene sheets [115], CNTs [116], and silicon dioxide [117]. This method needs higher temperature, which is helpful to reduce the viscosity of polymer and load more nanofillers, but also has the risk of decomposing polymers and nanofillers. The reason is owing to the existence of low thermal stability functional groups in the materials. When the temperature is too high, the fracture will occur, resulting in the deterioration of the performance of PNCs [118]. Moreover, the gap between the screws is too large to keep some aggregates of nanofillers evenly, which will not achieve the uniform monodispersing of nanofillers. So, it is necessary to combine other technologies to further improve the performance [119, 120].