Novel Preparation and Properties of Polypropylene−Vermiculite Nanocomposites

Abstract

A novel approach to the preparation of polymer nanocomposites utilizing a low-molecular-weight reactive modifying reagent has been developed in this study. This is the first report on the fabrication of in situ nanocomposites using maleic anhydride as a reactive reagent that acts both as a modifying additive for the polymeric matrix and as a swelling agent for the silicate. Accordingly, polypropylene−vermiculite nanocomposites with an intercalated or exfoliated structure can be achieved by simple melt mixing of maleic anhydride-modified vermiculite with polypropylene. The nanocomposite structure is evidenced by the absence of vermiculite reflections in the X-ray powder diffraction patterns. Tensile tests show that the tensile modulus and strength of the nanocomposites tend to increase dramatically with vermiculite addition. Such enhancement in mechanical properties results from the formation of intercalated and exfoliated vermiculite reinforcement in the composites. Finally, the thermal properties of the nanocomposites were investigated by means of dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The effects of maleic anhydride addition on the formation of nanometric reinforcement and on the mechanical properties of nanocomposites are discussed.

Polymer-clay Nano Composites

“…However, the water adsorption at equilibrium was the same for with and without clay. Permeability of CO 2 was half in polyimide-clay composite as compared to polymer without clay 36 .…”

“…However, the chemical treatment of the clay by dimethyl-octadecyl ammonium chloride before mixing facilitated the formation of polypropylene-clay nano composites. Improvements in mechanical properties of polypropylene have been achieved, in general, by melt-mixing with particulate (talc, mica, clay) and fibrous (glass, jute, aramid, carbon fibres) additives [34][35][36][37][38][39] . Ou 38 , et al filled nylon-6 with 50 nm silica particles and reported increase in tensile strength (15 %), strain to failure (150 %), Youngs modulus (23 %), and impact strength (78 %) with only 5 Wt per cent nano particles 38 .…”

The effect of matrix morphology on dynamic-mechanical properties of polypropylene/layered silicate nanocomposites

“…The dynamic mechanical response of PP/clay nanocomposites has been analyzed by many authors. In most cases [29][30][31][32][33][34][35][36][37][38][39] it has been shown that the addition of nanoclays increases the storage modulus of the material. However, contradictory results were found with respect to the glass transition temperature; in most of these works, T g was found to be practically unaffected by the presence of clays.…”

Thermal stability, mechanical and adsorption resistant properties of HDPE/PEG/Clay nanocomposites on exposure to electron beam

“…They are based on the use of a low concentration of expandable smectite clays, such as montmorillonite (MMT), in the matrix (Biswas et al [1], Vaia et al [2], Tjong et al [3], Kojima et al [4], Lagaly [5], Wang et al [6], Fong et al [7], Chen [8], Manias et al [9]). The addition of MLS in a polymeric matrix results in different clay distributions that do not always provide an improvement in performance.…”

“…The bulk of nanocomposite literature (Biswas et al [1], Vaia et al [2], Tjong et al [3], Kojima et al [4], Lagaly [5], Wang et al [6], Fong et al [7], Chen [8], Manias et al [9], Alexandre et al [10], Tabtiang et al [11], Ichazo et al [12], Gonzalez Montiel A et al [13], Vaia et al [14], LeBaron et al [15], Liu et al [16], Dennis et al [17], Kurokawa et al [18]) indicate that increased strength, or elastic modulus, considerably decreases strain to failure and ductility. In PE, this is further complicated by the nonpolar nature of PE, requiring the use of bridge molecules between the PE and the MLS.…”