Formulation and mechanical properties of polypropylene nanocomposites.

摘要

Polymer nanocomposites (PNC) are a new type of material, in which the reinforcement must have at least one dimension in a nanoscale. Polymer/clay nanocomposites provide great advantages in terms of different properties in comparison with conventional mineral-filled polymers. In this work, the preparation of polypropylene (PP)/clay nanocomposites by melt process (Brabender mixer) from five different chemistries of organo-nanoclays and five different coupling agents with different functional groups, such as maleic anhydride (MA), amine (NH2), onium ion (NH3+), has been carried out. It should be noted here that the NH3+ modified PP were first studied in this work. The effect of impurities in conventional coupling agents has also been investigated for the first time. Different processing temperatures, residence times and shear rates have been examined. The effects of parameters, such as type of coupling agent and clay, processing conditions, dispersion and interface interaction, were evaluated using different means, such as XRD, DSC, SEM, DMA, and mechanical properties. The rheological behavior of nanocomposites was also studied. The results obtained from this study provide a certain understanding on the relationship between the formulation, processing condition and performance. Significant improvement in stiffness and storage modulus was observed in nanocomposites formulated with coupling agent. However, the extent of the improvement of the nanocomposites' performance depends on the type of the clay and the coupling agent. In addition, the processing condition had great effects on the properties of PP nanocomposites.