We prepared intercalated organic montmorillonite (OMMT) from a pristine MMT and long-alkyl-chain quaternary ammonium salts (LACQAS). X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analyses revealed that the amount, carbon atoms, and alkyl chains of LACQAS influenced the large value of d (001) of OMMT significantly. The d (001) stabilized at 100–150 mmol·(100 g) -1 of LACQAS/MMT. The single LACQAS cations arranged in the form of a lateral layer or half-paraffin-type molecular structure between MMT layers, whereas the dual and triple LACQAS cations arranged in the form of a paraffin-type molecular structure. The pyrolysis temperature and maximum pyrolysis rate of OMMT increased greatly compared with those of MMT. The thermal weight loss of MMT was caused by the removed absorbed and structural water, whereas that of OMMT was by the pyrolysis of LACQAS. With the help of the Agrawal integral equation, the pyrolysis kinetics of MMT and OMMT were obtained using a trial-and-error method.

In this study, microwave plasma was used to treat the surface of Pinus yunnanensis wood under the conditions of 220 V of input voltage, 20 μA of filament current, 8.8 mW of output power, 11 mW of reflected power, 2450 MHz of frequency, and 700 Pa of vacuum. The microwave plasma presented very significant treatment effects on the treated surface, even under weak treatment conditions, for example long treatment distance of 120 mm and short treatment time of 60 s. The treated surface showed better surface wettability, and the contact angles on the treated surface measured from deionized water, glycerin, and diiodomethane decreased sharply, even decreased to 0°. The treated surface also presented higher surface free energy, for example, 61.4–62.8 mJ m−2, being greatly improved by microwave plasma compared to that of untreated surface of 46.5 mJ m−2. The bond strength of the treated surface was 7.34 MPa, about 16 % higher than 6.31 MPa for untreated surface. The best treatment effect was obtained for the treatment distance of 120 mm and treatment time of 60–300 s. This technique might be widely used in wood modification and wood processing.

In the paper, an exfoliated nano-composite was prepared by vinyl acetate (VAc), montmorillonite (MMT) and dioctadecyl dimethyl ammonium bromide (DOAB). Then it was mainly studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and static tension. Its rheology was also investigated by the power-law function equation and the Cross-Williamson model viscous equation. Results showed that the exfoliated nano-composite was obtained. Linear macromolecular chains of polyvinyl acetate (PVAc) were formed in the layers of MMT-DOAB. MMT-DOAB was exfoliated into layers or sheets of nano-particles, and randomly dispersed in the matrix of PVAc. The particle diameter of MMT-DOAB was from 25 nm to 75 nm, while PVAc's was from 250 nm to 500 nm. They randomly dispersed together. The smaller MMT-DOAB particles were adsorbed around the bigger PVAc particles; they formed the "Strawberry" structure. In addition, PVAc and PVAc-MMT-DOAB were pseudo-plastic Non-Newtonian fluids, they all possessed the normal stress effect (or Weissenberg effect), that was the pole-climbing phenomenon. The reasonable addition of MMT-DOAB in polymerization was better but not more than 2.0 wt% of VAc.

In this study, we combined silver nanowires with cupro fabrics using a dipping-drying method to prepare electrically conductive fabrics. The silver nanowires were first adhered to and then absorbed by microfibers to form electrically conductive fibers. They also filled the gaps and spaces between the microfibers, and were stacked or piled together to form networks with high electrical conductivity. The electrically conductive fabric had low resistance and good stretchability, e.g., 0.0047–0.0091 Ω in the strain range of 0–190%. They also exhibited stable electrical conductivity, as well as excellent flexibility, which remained even when the fabric was stretched, shrunk, or bent. The results show that the electrically conductive fabric can be used as a smart textile, especially in fields associated with weaving, clothing, food products, lifestyle products, medicine, biology, electronics, aviation, and military equipment and accessories.

In this study, vinyl acetate, -hydroxymethyl acrylamide (NMA), and organic montmorillonite intercalated by a dioctadecyl dimethyl ammonium bromide surfactant (MMT-DOAB) were used to prepare exfoliated nanocomposites through in situ polymerization. Wide-angle X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, power-law function equation, Newtonian fluid flow equation, Cross–Williamson model viscous equation, Hooke's law, and Poisson's ratio equation revealed the structures, dispersion, rheology, and static tensile properties. The exfoliated nanocomposites were pseudoplastic non-Newtonian fluids with good dispersion in water, great storage stability, and high static tensile strength at 6.89–8.15 MPa. The contents of NMA and MMT-DOAB increased with the changes in synthesis precursors, as the calculated molecular weights did.

In this study, we prepared high-performance printable, stretchable electrical conductor from waterborne polyurethane and micro-silver flakes. The solidification and thermal degradation were investigated using differential scanning calorimetry and thermogravimetric analysis methods. The electrical conductor achieved solidification by volatilizing and removing the free water. The thermal degradation mainly happened in the range of 250–450 °C caused by the pyrolysis of the polymeric matrix of polyurethane. The pyrolysis kinetic equations were obtained using the kinetic methods, e.g., dα/dt = e22.16(1 − α)0.78 α 0.13e(−149.14/RT) for the polyurethane, dα/dt = e22.76(1 − α)0.84 α 0.11e(−150.69/RT), dα/dt = e21.43(1 − α)0.77 α 0.06e(−143.77/RT), and dα/dt = e19.06(1 − α)0.75 α 0.12e(−130.53/RT) for the electrical conductor containing 80, 85, and 90 % mass percentage of micro-silver flakes, where α was the fractional extent conversion at a given time t (or a given temperature T). Their overall order of reaction was 0.91, 0.95, 0.83, and 0.87, respectively, less than 1, demonstrating the thermal degradation was a single, simple reaction.

1,1-Bis(t-hexylperoxy)-3,3,5-trimethyl cyclohexane was introduced to thermally initiate the curing of vinyl ester resin, and a dynamic differential scanning calorimetry method was applied to investigate the thermally initiated curing procedures.

In this study, high performance electrically conductive adhesives were fabricated from a vinyl ester resin, a thermal initiator, silver coated copper powders, and pure silver powders, without using any other coupling agent, dispersing agent, and reducing agent. The heat cured copper-silver powders filled electrically conductive adhesives presented low bulk resistivity (e.g., 4.53 × 10−5 Ω·cm) due to the silver powders that had given high electrical conductivity to the adhesives, and high shear strength (e.g., 16.22 MPa) provided by the crosslinked structures of vinyl ester resin. These high performance copper-silver powders filled electrically conductive adhesives have lower cost than those filled by pure silver powders, which can be well used in the electronic packaging and can enlarge the application prospects of electrically conductive adhesives.

In this study, we presented the use of polyurethane, ethylene-vinyl acetate hotmelt, and nano hexagonal boron nitride particles to prepare high surface adhesion polymer fibers via an elertrospinning method. The shear strength, dynamic tensile properties, and surface morphology have been investigated. These polymer fibers were found to have high shear strength, high tensile stress, and high tensile strain, which may have a good potential application in the matrix materials for thermal interface materials. Polymer fibers with and without nano hexagonal boron nitride particles showed the shear strength of 6.52 MPa and 5.44 MPa respectively on being heated up at 150°C for 45 min.

Highly ordered 'Chrysanthemum petal' arrangements of silver nano wires were fabricated in a biodegradable polymer of polyvinyl alcohol using a simple one-step blending method without any template. The degree of the arrangement increased with the decreasing content of polyvinyl alcohol. The mechanism for the formation of these 'Chrysanthemum petal' arrangements was discussed specifically. These 'Chrysanthemum petal' arrangements will be helpful to increase the electrical conductivity of silver nano wires films.

In this study, we introduced N-hydroxymethyl acrylamide and an organic montmorillonite intercalated by an octadecyl trimethyl ammonium bromide surfactant together into the in situ polymerization of polyvinyl acetate to form exfoliated nanocomposites. Wide-angle X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, power-law function equation, Newtonian fluid flow equation, Cross-Williamson model viscous equation, Hooke's law, and Poisson's ratio equation revealed the structures, dispersion, rheology, and static tensile properties. The exfoliated nanocomposites were pseudo-plastic non-Newtonian fluids, presented a good dispersion in water, a great storage stability, and a high static tensile strength at 6.78-8.06 MPa.

In this paper, we fabricated electrically conductive adhesives using vinyl ester resin and micro silver flakes, and then cured the adhesives by heat without any catalysts or initiators. The curing temperature was above 200 °C, and the curing time about 30 min. Under these heat curing conditions, the double bonds in the adhesives reached a high conversion (α) around 98.88 % calculated from the Fourier transform infrared spectroscopy analysis. The curing kinetics of heat curing products was studied using Ozawa method and deduced by assuming a constant activation energy (E). The curing kinetic equation was obtained as dα/dt = e17.70(1 − α)1.19 α 0.41e(−94.32)/RT) with E = 94.32 kJ mol−1. The heat curing followed the shrinking core model from the resin-particle system. The data calculated from the kinetic equation agreed well with the experimental data, showing that the Ozawa method could evaluate the curing kinetics effectively. Furthermore, a comprehensive and in-depth understanding of the curing kinetics of heat curing electrically conductive adhesives has been achieved with this Ozawa method.

In this study, we synthesized a poly( N -isopropylacrylamide) (PNIPAm) through the polymerization of N -isopropylacrylamide in distilled water with azodiisobutyronitrile as the initiator and a bisadenine-functionalized poly(ethylene oxide) (A-PEO-A) from the reaction of adenine with a difunctionalized toluenesulfonyl-PEO. When blended together in distilled water, PNIPAm and A-PEO-A formed supramolecular aggregates stabilized through complementary multiple hydrogen bonds between the amide groups of PNIPAm and the adenine units of A-PEO-A. Agrawal integral equation and rheometry revealed the rheological kinetics of supramolecular assemblies, which were influenced significantly by the spherical micelles, large associated aggregates of spherical micelles, network structures, and toroid structures formed in aqueous solutions.

In this study, the exfoliated montmorillonite was prepared through the click chemistry of a propargyl-containing intercalator with singly or multiply azido-functionalized polyhedral oligomeric silsesquioxane nanoparticles. Thermogravimetric analyses revealed that the pyrolysis kinetics had a close relationship to the layered structures, exfoliated structures, and cage-like molecules of polyhedral oligomeric silsesquioxane nanoparticles. The pyrolysis of exfoliated montmorillonite had a mechanism function of Avrami–Erofeev equation, and the kinetic compensation effect equation revealed the pyrolysis.

In this study, the electrically conductive adhesives were fabricated using vinyl ester resin and micro silver flakes, and then a high-intensity pulsed light was introduced to cure the adhesives under an ambient atmosphere at room temperature. The thermal degradation kinetics of photonically cured products was studied using the Friedman method and deduced by assuming a variable activation energy (E). The value of E spanned from 110 to 233 kJ mol−1, which first increased, then decreased, and finally increased again as the thermal degradation proceeded. The kinetic equation of thermal degradation was obtained as dα/dt = e26.62(1 − α)2.22 α 1.85e(−E(α)/RT) with E(α) = 961.73α 3 − 1453.9α 2 + 669.79α + 79.859, α ∈ (0, 1), where α was the fractional extent conversion at a given time (or given temperature). The overall order of reaction was 4.07 and >1, demonstrating that the thermal degradation was complex. With the Friedman method, a comprehensive and in-depth understanding of the thermal degradation kinetics of photonically cured electrically conductive adhesives has been achieved.

In this study, N-hydroxymethyl acrylamide (NMA) and vinyl acetate (VAc) were used in order to prepare secondary emulsions; additionally urea was then introduced into the polymerization to form ternary emulsions, adjusting different proportions of the three components. Compared to pure polyvinyl acetate, these two emulsion types presented shorter curing time, improved water resistance, and higher bond strength; this is based on the crosslinking ability introduced by the NMA, enabling such a partial crosslinking already during the polymerization process and during storage. The viscosity, solid content, storage stability, curing and drying behavior, water resistance, delamination time, and bond strength were influenced by the proportions of NMA and urea in the two systems. Urea had a positive effect on the wet bond strength, but a negative effect on the dry bond strength. The proportion of NMA and of urea during the polymerization preferably was 1–2 % based on VAc.

Super flexible, highly conductive electrical compositors were hybridized from polyvinyl alcohol and silver nanowires using a simple one-step blending method.

In this study, an exfoliated montmorillonite was introduced into a benzoxazine matrix-prepared from paraformaldehyde, aniline, and phenol-to form polymer/exfoliated clay nanocomposites. Wide-angle X-ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, transmission electron microscopy, and contact angle measurements revealed the structures and thermal and mechanical properties of these polybenzoxazine/clay nanocomposites; the montmorillonite was exfoliated into nanoparticles (single sheets or layers) that were dispersed in the polybenzoxazine matrix. The incorporation of the exfoliated montmorillonite improved the polymer's glass transition and thermal decomposition temperatures, mechanical properties, and surface hydrophobicity.

ABSTRACTIn this study, we used vinyl acetate (VAc), N‐hydroxymethyl acrylamide (NMA), and montmorillonite (MMT) to prepare polyvinyl acetate (PVAc), PVAc–NMA, PVAc–MMT, and PVAc–NMA–MMT. Dynamic mechanical and thermogravimetric analysis revealed their glass transition, cold crystallization, and pyrolysis kinetics. PVAc–NMA, PVAc–MMT, and PVAc–NMA–MMT can be applied in harsh or low temperature conditions and surroundings. They are homogeneous amorphous linear polymers and all have cold crystallization phenomena. NMA and MMT did not have any significant effect on pyrolysis temperatures, but delayed the thermal degradation processes. The glass transition, cold crystallization, and pyrolysis kinetics were analyzed using Agrawal integral equation. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21393; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21393