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In this paper, we report an effective method for the preparation of polydimethyl siloxane (PDMS) containing only 0.5 wt % π-conjugated truxene micromolecule. The as-prepared truxene/PDMS composite had high dieletric constant (k) due to the regularly rigid structures, special π-conjugated structure and monodisperse nature of truxene, which can form a large no. of parallel micro-capacitors under actuated electric field. In addition, the elastic modulus of truxene/PDMS composite was increased slightly only with a good flexibility. As a result, compared to pure silicone elastomer (4.52%), the truxene/PDMS composite exhibited a greater strain of 11.56% at a low electric field of 5.5 V/μm (about 2.56 times increase).

Polymer nanocomposites are usually made by incorporating dried nanoparticles into polymer matrices. This way not only leads to easy aggregation of nanoparticles but also readily brings about opaqueness for nanocomposites based on functionally transparent polymers. In this letter, transparent ZnO/epoxy nanocomposites with high-UV shielding efficiency were prepared via two simple steps: first, in situ preparation of zinc hydroxide (Zn(OH)2)/epoxy from the reaction of aqueous zinc acetate (Zn(Ac)2·2H2O) and sodium hydroxide (NaOH) at 30°C in the presence of high-viscosity epoxy resin; second, thermal treatment of the as-prepared Zn(OH)2/epoxy hybrid into ZnO/epoxy composites. Optical properties of the resultant ZnO/epoxy nanocomposites were studied using an ultraviolet–visible (UV–vis) spectrophotometer. The nanocomposites containing a very low content of ZnO nanoparticles (0.06 wt %) possessed the optimal optical properties, namely high-visible light transparency and high-UV light shielding efficiency. Consequently, the as-prepared ZnO/epoxy nanocomposites are promising for use as novel packaging materials in lighting emitting diodes technology. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

In this article, the ZnS/epoxy nanocomposites were successfully prepared by the reaction of zinc acetate and H2S gas via a simple step. Epoxy resin acted as the matrix for the formation of ZnS nanoparticles (10–20 nm) in the reaction system and kept them from agglomerating. The structure, composition, and mechanical properties of the resultant products were successfully investigated by powder X-ray diffraction, transmission electron microscope, field emission scanning electron microscope, energy dispersive X-ray fluorescence, and universal testing machine. Meanwhile, by employing differential scanning calorimetry (DSC) we had studied, under nonisothermal condition, the kinetic analysis of the cure reaction which was performed using two classic models: Kissinger and Flynn-Wall-Ozawa. The activation energy of curing reaction was 74.63 kJ/mol and 77.57 kJ/mol, respectively, by Kissinger's and Flynn-Wall-Ozawa's methods. The possible mechanism of preparation of ZnS/epoxy composites was discussed in this article. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

In this paper, ZnO/epoxy composites with homogeneous dispersion were prepared via two simple steps: firstly, in situ preparation of zinc hydroxide (Zn(OH) 2 )/epoxy from the reaction of aqueous zinc acetate (Zn(Ac) 2 ·2H 2 O) and sodium hydroxide (NaOH) at 30 °C in the presence of high viscosity epoxy resin; secondly, thermal treatment of the as-prepared Zn(OH) 2 /epoxy hybrid into ZnO/epoxy composites. Meanwhile, the structure, composition and mechanical properties of the resultant products were successfully investigated. From the result of characterization we found that the composite had the optimal mechanical property at ZnO fraction of 5 wt.%. Compared to pure epoxy resin, the improvement of ultimate tensile stress, elongation at break, tensile modulus and flexural strength achieved about 40.84%, 24.35%, 27.27% and 51.43%, respectively. The crack arresting mechanisms included particle matrix debonding, plastic void growth, in the composites with a stronger interface, significant plastic deformation of the matrix around the well bonded particles. At the same time, the possible reactive mechanism of the preparation of ZnO/epoxy composite was discussed in this paper.

A series of linear and X-shaped oligo(para-phenylene) derivatives functionalized with fluorene ethynylenes 1, 3 and 4 were synthesized through sequent Sonogashira coupling and Suzuki–Miyaura reaction in high yield. The electron-donating group –OCH3 and electron-withdrawing counterparts –CF3 were introduced to tune the spectra properties of compounds 3 and 4. The detail investigation of their photophysical properties in solution and film indicated that the introduction of both –OCH3 and –CF3 makes maximum emission distinct red-shift in comparison with parent compound 1, but the latter more prominently.

In this article, submicron and micron calcium copper titanate (CCTO) crystallites with different morphologies were successfully designed and prepared by directly thermal treatment method and molten salt method, respectively. Then, the silicone elastomer filled with self-prepared CCTO particles had high dieletric constant, low dielectric loss, and actuated strain which was greatly improved at low electric field. The dieletric constant at 50 Hz obviously increased from 2.15 for pure silicone elastomer to 4.37 and 4.18 for the submicron and micron CCTO/poly (dimethyl siloxane) (PDMS) composites. The dielectric loss of the composites retained at a low value (less than 0.06). Meanwhile, the elastic modulus of CCTO/PDMS composites was increased slightly only with a good flexibility. Compared to pure silicone elastomer (2.25%), the submicron and micron CCTO/PDMS composites with 2 wt % content exhibited a greater strain of 7.69% and 9.83% at a low electric field of 5 V/μm. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42613.

In this study, poly(propylene glycol diacetate)s (PPGDAs) with different molecular weights were obtained by the esterification reaction of poly(propylene glycol) and acetic anhydride. We effectively reduced the residual moisture and hydrophilicity of PPGDA. Then, poly(dimethyl siloxane) (PDMS) was modified by the addition of only 5 wt % PPGDA, which possessed a high dielectric constant (k) and a large actuated strain at a low electric field. PPGDA was used to enhance the molecular polarity because of the more polar oxygen atoms and the greater number of ester groups. The great increase in k and the low elastic modulus of the PPGDA–PDMS composites lead to a great increase in the electromechanical sensitivity. When the molecular weight of PPGDA was about 4000, the PPGDA–PDMS composites had the largest actuated strain. As a result, compared to the pure silicone elastomer (8.94%), it exhibited a greater strain of 17.31% at a low electric field of 10.5 V/μm (an increase of ca. 1.94 times). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45329.

In this article, copper (Cu) crystallites were successfully prepared via low temperature molten salt method, and the possible formation mechanisms were proposed. The conductive fillers of multiwalled carbon nanotubes (MWCNTs) and as-prepared Cu particles were designed and introduced into acrylonitrile-butadiene-styrene (ABS) blend to prepare different conductive composites. The dispersion states of conductive fillers and the morphologies of the composites were characterized using a field emission scanning electron microscope. The electrical resistivity of different composites was measured. The results showed that Cu and MWCNTs exhibited a synergistic effect in decreasing the electrical resistivity of the Cu/MWCNTs/ABS composites, because Cu that could locate between MWCNTs chain segments provides a better charge transport in the conductive pathways. Compared with pure ABS, the tensile strength, elastic modulus and thermal stability of the Cu/MWCNTs/ABS composites were significantly improved with the incorporation of Cu and MWCNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41738.