Abstract
Polymer nanocomposites based on organically modified layered silicates, e.g., organic-montmorillonite (org-MMT), exhibit attractive properties, such as increased mechanical properties, reduced gas and liquid permeability, improved heat, solvent and UV resistance, greater dimensional stability at elevated temperature, improved optical and electrical properties, and enhanced flame retardant properties [1–4]. Three different methods, in situ polymerization, polymer intercalation from solution, and direct polymer melt intercalation, have been used to synthesize layered silicate-based polymer nanocomposites [5]. The third method would greatly expand the commercial opportunities for nanocomposite technology because of its low cost, high productivity and compatibility with current polymer processing techniques [6]. In recent years, some researchers employed the direct melt intercalation technique to prepare the polymer nanocomposites [6–12]. However, these studies used a laboratoryscale twin screw extruder or internal mixer to yield nanocomposites and then investigated the microstructure and properties of only the as-extruded pellets or samples. Recently, the authors [13] used an industrial-scale extrusion blow molding machine to make packaging bottles from polypropylene (PP) or high-density polyethylene (HDPE)/org-MMT nanocomposites prepared by using a twin screw extruder. The changes of the microstructure of nanocomposites occurring after processing using a single screw extruder were investigated preliminarily. In this work, PP/org-MMT nanocomposites were prepared by direct melt intercalation using an industrial-scale co-rotating twin screw extruder. The as-extruded pellets were then extruded into ribbons by using an industrial-scale single screw extruder. The major focus was on the effects of mixing type of the screw on the microstructure changes of polymer nanocomposites. The microstructure of specimens was investigated by wide-angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). The org-MMT (Fenghong Clay Co.) was supplied as particles with an average size of 25 μm. The polymer matrix was isotactic PP homopolymer (F401,
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call