Shear Strength and Morphological Study of Polyurethane- OMMT Clay Nanocomposite Adhesive Derived from Vegetable Oil-Based Constituents

In the current work,we have synthesized vegetable oil-based polyurethane-OMMT clay nanocomposite(PUNC)adhesive with the incorporation of different wt%of organically modified nanoclay(1 to 5 wt%)into the biobased polyurethane(PU)matrix through in-situ polymerization process via ultrasonication method.At the initial stage,PU adhesive was prepared using polyol and partially biobased aliphatic isocyanate,wherein polyol was derived from the transesterified castor oil using ethylene glycol.The formation of PU and PUNC adhesive was confirmed using Fourier transform infrared(FTIR)spectroscopy analysis.The tensile strength of PU with different wt%of nanoclay was determined and the analysis showed that the loading of 3 wt%of nanoclay within the PU matrix showed better performance as compared to the others.Furthermore,shear strength of PU and PUNC(3 wt%nanoclay)adhesives were determined using lap shear test,in which PUNC adhesive showed higher adhesive strength at 70°C.Subsequently,the dispersibility of OMMT nanoclay within the PU matrix along with exfoliation and amorphous structure was confirmed through wide angle X-ray diffractometer(WAXD)and transmission electron microscopy(TEM)analysis.The phase separation structure was analyzed using dynamic mechanical analysis(DMA).The analysis revealed that with the addition of organically modified nanoclay in the PU matrix,the glass transition temperature(Tg)of the damping curve was shifted towards higher temperature.

The Effect of Water Absorption on Mechanical Properties of Wood Flour/Wheat Husk Polypropylene Hybrid Composites

The main objectives of this research were to study the effect of water absorption on mechanical properties of hybrid fiber reinforcement for polypropylene composites. The poor resistance towards water absorption is one of the draw- backs of natural fibers. Hybrid filler-polypropylene composites are subjected to water immersion tests in order to study the effects of water absorption on the mechanical properties. Composites specimens containing 30 phr and 40 phr fiber weight were prepared by melt blending process. Water absorption tests were conducted by immersion specimens in distilled water at room temperature for different time durations (24, 48, 72, 96, 120, 144, 168, 192 hours). The tensile, flexural and impact properties were investigated before and after water absorption. The percentage of moisture uptake increased as the increasing order of the filler loading due to the high cellulose content. The phase morphology of wood flour/wheat husk polypropylene hybrid composites were investigated by SEM, the dynamic mechanical properties of the composite are analyzed by DMA & wheat, wood filler interaction are analyzed by FT-IR.

Wire-Shaped 3D-Hybrid Supercapacitors as Substitutes for Batteries

We report a wire-shaped three-dimensional(3D)-hybrid supercapacitor with high volumetric capacitance and high energy density due to an interconnected 3D-configuration of the electrode allowing for large number of electrochemical active sites,easy access of electrolyte ions,and facile charge transport for flexible wearable applications.The interconnected and compact electrode delivers a high volumetric capacitance(gravimetric capacitance)of 73 F cm−3(2446 F g−1),excellent rate capability,and cycle stability.The 3D-nickel cobalt-layered double hydroxide onto 3D-nickel wire(NiCo LDH/3D-Ni)//the 3D-manganese oxide onto 3D-nickel wire(Mn3O4/3D-Ni)hybrid supercapacitor exhibits energy density of 153.3 Wh kg−1 and power density of 8810 W kg−1.The red lightemitting diode powered by the as-prepared hybrid supercapacitor can operate for 80 min after being charged for tens of seconds and exhibit excellent electrochemical stability under various deformation conditions.The results verify that such wire-shaped 3D-hybrid supercapacitors are promising alternatives for batteries with long charge–discharge times,for smart wearable and implantable devices.