89 research outputs found
Investigation on the competing effects of clay dispersion and matrix plasticisation for polypropylene/clay nanocomposites. Part I: morphology and mechanical properties
The key compatibiliser role of maleated polypropylene (MAPP) to improve the clay dispersability has been explicitly addressed in the fabrication process and material characterisation of polypropylene (PP)/clay nanocomposites. However, its matrix plasticiser role, which has been rarely mentioned, could adversely influence the excellent mechanical properties of such nanocomposites, resulting from the homogeneous clay dispersion. PP/clay nanocomposites in the presence of MAPP were prepared by twin screw extrusion and subsequently injection moulded with three typical material formulations in fixed parametric settings: (1) weight ratio (WR) of clay and MAPP, WR = 1:2; (2) MAPP content of 6 wt% and (3) clay content of 5 wt%. The morphological structures and mechanical properties of PP/clay nanocomposites were examined by using X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and universal mechanical testing. The further improvement of mechanical properties was evidently hindered with very inconsiderable alteration of morphological structures in terms of the clay dispersion level. This observation could be ascribed to the change of MAPP role from a compatibiliser to a plasticiser because of its excessive amount used above a certain saturation level, which was found in the range of 3â6 wt% in MAPP contents for the enhancements of tensile and flexural properties of PP/clay nanocomposites
Unveiling thermal transitions of polymers in subnanometre pores
The thermal transitions of confined polymers are important for the application of polymers in molecular scale devices and advanced nanotechnology. However, thermal transitions of ultrathin polymer assemblies confined in subnanometre spaces are poorly understood. In this study, we show that incorporation of polyethylene glycol (PEG) into nanochannels of porous coordination polymers (PCPs) enabled observation of thermal transitions of the chain assemblies by differential scanning calorimetry. The pore size and surface functionality of PCPs can be tailored to study the transition behaviour of confined polymers. The transition temperature of PEG in PCPs was determined by manipulating the pore size and the poreâpolymer interactions. It is also striking that the transition temperature of the confined PEG decreased as the molecular weight of PEG increased
Influence of Nanogels on Mechanical, Dynamic Mechanical, and Thermal Properties of Elastomers
Conducting and Electric Force Microscopy of CNT Polymer Nanocomposites: Understanding the Connectivity of the Percolative Network
MRS Communications, Polymers and Soft Matter special issue, Part A the functionality of polymers: Fundamentals to technology
Effect of polyethylene glycol-intercalated organoclay on vulcanization characteristics and reinforcement of natural rubber nanocomposites
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