Maleic anhydride (MA) is incorporated into poly(lactic acid) (PLA)/poly(propylene carbonate) (PPC) blends to modify its properties through melt compounding. It is interesting to note that the toughness of PLA/PPC blends can be improved by 1355% while the strength is almost kept constant by adding very low content (as low as 0.9%) of MA into the blends. However, higher MA content in the blends leads to decrease in strength and further increase in toughness indicating an obvious plasticizing effect, while MA is shown to have no effect on the toughness of neat PLA. Rheological, scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) studies have been carried out to understand the above results. It is believed that the improvement in mechanical performance originated from the largely retained molecular weight of PPC and improved interfacial interaction after processing. And relative large amount of MA in the blends is shown to mainly plasticize the PPC phase rather than the PLA phase. Such an effective method could provide PLA based biodegradable polymer blends with novel properties for industrial applications
The electrochemical stability of electrolytes is essential to the working potential of supercapacitors. Ionic liquids (ILs) are being considered as safe alternatives to current organic electrolytes and attracting extensive interests owing to their inflammability, widened potential windows, and superior ionic conductivity. Novel supercapacitors with IL electrolytes exhibit attractive energy density and can be utilized in various energy storage systems. Most previous studies focused on electrochemical performances, while rare attentions were devoted to energy storage process details or mechanisms. This review comprehensively summarizes the latest progress on formulated IL electrolytes for different types of supercapacitors, with an emphasis on the intrinsic understanding of the related energy storage mechanisms. Subsequently, comparisons of various IL-based liquid-state electrolytes as well as the state-of-the-art advancements in optimizing ILs electrolytes are introduced. The authors attempt to reveal the inherent correlation between the usage of IL electrolytes and the properties of supercapacitors via referenced works. Some emerging applications of ionogel electrolytes based on conventional polymers and poly(IL)s for flexible supercapacitors are also presented, including the existing problems. In addition, challenges and future perspectives of research in this field are highlighted.
The formation of a shish kebab (SK) structure, where carbon nanotubes (CNTs) serve as shish and polymer lamellae serve as kebab, is particularly interesting and provides a novel way to enhance the polymer-CNT interface. A fine SK structure is achieved through melt spinning. High density polyethylene and pristine CNTs were first compounded in an extruder. The compound was then spun into fibers with different draw ratios with the aid of a capillary rheometer. The crystalline structure and mechanical behavior were characterized by scanning electron microscopy, differential scanning calorimetry, two-dimensional wide-angle X-ray scattering, polarized Raman spectroscopy, and tensile testing. An increase in tensile strength as high as 3 times has been achieved in the fiber. The formation of SKs is considered as the main mechanism responsible for the enhanced interfacial interaction and excellent tensile property.
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