Structure and properties of polypropylene/organic rectorite nanocomposites

Melt blending using a twin-screw extruder was used to prepare composites of Polypropylene (PP)/Organic rectorite (PR). The organic rectorite (OREC) was modified with dodecyl benzyl dimethyl ammonium bromide (1227). Wide-angle X-ray diffraction (WAXD) and transmission electron microscopy were used to investigate the dispersion of OREC in the composites. The d spacings of OREC ill PR composites was greater than ill OREC itself. The dispersion of OREC particles ill file PP polymer matrix was fine and uniform when the clay content was Small (2 wt%). The rheology was characterized using a capillary rheometer. The Processing behaviour Of the PR system improved as the amount of OREC added increased. Non-isothermal crystallization kinetics were analysed using differential scanning calorimetry. It was shown that the of OREC had a heterogeneous nucleation effect on PP, and call accelerate the addition crystallization. However. only when fine dispersion was achieved, and at lower rates, of temperature decrease, was the crystallinity greater. Wide-angle X-ray diffraction and polarized light microscopy were used to observe the crystalline form and crystallite size. The PP ill the PR composites exhibited an alpha-monoclinic crystal form, as, in pure PP, and in both cases a spherulite structure was observed. However, the Smaller spherulite size in the PR systems indicated that addition of OREC can reduce the crystal Size Significantly, which might improve the 'toughness' of the PP. The mechanical Properties (tensile and impact Strength) improved when the amount of OREC added was appropriate. Dynamic mechanical analysis showed that the storage modulus (E') and loss modulus (E '') of the nanocomposites were somewhat greater than those of pure PP When all appropriate amount of OREC was added. Finally, thermogravimetric analysis showed that the PR systems exhibited if greater thermal stability than was seen with pure PP.