We fabricated novel superhydrophobic coatings based on SiO₂ nanoparticles combined with NH₂-terminated silicone (SN₂) or SN₂-modified polyurethane (SN₂-prePU) by alternately spin-coating them onto glass slides. The final fabricated surface contained SN₂/SiO₂ or SN₂-prePU/SiO₂ bilayers. The conditions of spin-coating method were also explored. SN₂-prePU with different SN₂/prePU molar ratios were synthesized to study the influence of SN₂ ratio on the water contact angles of ultimate spin-coated surfaces. The surface was found to be tunable from hydrophobic to superhydrophobic by choosing SN₂-prePU with different SN₂/prePU molar ratios or SN₂ content. Water droplets easily rolled off on these superhydrophobic surfaces. Surfaces coated with SN₂/SiO₂ bilayers showed better transparency, whereas surfaces coated with SN₂-prePU(2 : 1)/SiO₂ bilayers exhibited better durability. Droplets of varied pH were prepared to test the anti-wettability of the coatings. Results showed that the as-coated surfaces had stable superhydrophobicity to droplets with pH values ranging from 1 to 14. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41500.

Propylene random copolymer (PPR)/styrene-ethylene-butylene-styrene block copolymer (SEBS)/compatibilizer/organic-montmorillonite (OMMT) quaternary nanocomposites and PPR/compatibilizer/OMMT ternary nanocomposites were prepared via two-stage melt blending and influences of compatibilizers, maleic anhydride (MA) grafted styrene-ethylene-butylene-styrene copolymer (SEBS-g-MA), poly(octene-co-ethylene) (POE-g-MA), or propylene block copolymers (PPB-g-MA), on rheology and mechanical properties of the nanocomposites were investigated. The results of X-ray diffraction measurement and transmission electron microscopy observation showed that OMMT layers were mainly intercalated in the nanocomposites except for the mainly exfoliated structure in the quaternary nanocomposites using POE-g-MA as compatibilizer. The nanocomposites exhibited pseudo-solid like viscoelasticity in low frequencies and shear-thinning in high shear rates. As far as OMMT dispersion was concerned, POE-g-MA was superior to SEBS-g-MA and PPB-g-MA, which gives rise to the highest viscosities in both the ternary and quaternary nanocomposites. The quaternary nanocomposites containing POE-g-MA were endowed with balanced toughness and rigidity. It was suggested that a suitable combination of compatibilizer and SEBS was an essentially important factor for adjusting the OMMT dispersion and distribution, the rheological and mechanical performances of the nanocomposites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The nonlinear phase-separation behavior of poly(methyl methacrylate)/poly(styrene-co-maleic anhydride) (PMMA/SMA) blends over wide appropriate temperature and heating rate ranges was studied using time-resolved small-angle laser light scattering. During the non-isothermal process, a quantitative logarithm function was established to describe the relationship between cloud point (T_c) and heating rate (k) as given by T_c = Alnk + T₀, in which the parameter A, reflecting the heating rate dependence, is much different for different compositions due to phase-separation rate and activation energy difference. For the isothermal phase-separation process, an Arrhenius-like equation was successfully applied to describe the temperature dependence of the apparent diffusion coefficient (D_app) and the relaxation time (τ) of the early stage as well as the late stage of spinodal decomposition (SD) of PMMA/SMA blends. Based on the successful application of the Arrhenius-like equation, the related activation energies could be obtained from D_app and τ of the early and late stages of SD, respectively. In addition, these results indicate that it is possible to predict the temperature dependence of the phase-separation behavior of binary polymer mixtures during isothermal annealing over a range of 100 °C above the glass transition temperature using the Arrhenius-like equation. © 2012 Society of Chemical Industry

A type of lanthanide (La(III))-containing ionomer based on acrylate processing aid (ACR) for poly (vinyl chloride) (PVC) was synthesized, and influence of the ionomer on thermal stabilization of PVC was investigated with visual color comparison and Congo red methods. Results revealed that the ionomer with a suitable La(III) content behaved as a good costabilizer to PVC. It was able to extend static stabilization time of PVC and postpone “zinc burning.” The stabilizing efficiency of the ionomer to PVC depended on ion content, which was discussed in terms of Eisenberg–Hird–Moore model. Moreover, Fourier transform infrared test verified that this ionomer can react with zinc stearate (ZnSt₂) to form some new structures, which is responsible for postponing “zinc burning.” The ionomer and epoxidized soybean oil exhibited a synergistic effect on the stabilizing efficiency of calcium stearate (CaSt₂)/ZnSt₂ stabilizer to PVC compounds. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Influence of filler network on Payne effect and modulus recovery for vapor grown carbon nanofiber (VGCF)/polystyrene (PS) composites with VGCF content above electrical percolation threshold was studied by using simultaneous measurements of viscoelasticity and electrical conductivity. The strain softening seems to be closely related to breakdown of filler network. Recovery tests of modulus and electrical conductivity by means of time sweep indicate that the reformation of deformed VGCF network structure could not be completed in several hours. Compared with recovery behavior of carbon black (CB) and silica (SiO₂) network, the reformation of VGCF network appears more difficult. Moreover, solidification of composites exerts some effect on modulus recovery. The filler network disrupted by small strain can be perfectly recovered by matrix solidification while the initial filler structure collapsing at large strain is only partially restored. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers

The thermally induced phase-separation behavior of a polystyrene/poly(vinyl methyl ether) (PS/PVME) blend was studied mainly using time-resolved small-angle light scattering, as a function of temperature and heating rate. Under a non-isothermal field, the dependence of the critical temperature on heating rate deviated obviously from linearity, even at very low heating rates. Such a nonlinear dependence was consistent with the deviation from linearity of the temperature dependence of the isothermal phase-separation behavior in a wider temperature range from 100 to 140 °C. It was also found that a Williams–Landel–Ferry (WLF)-like equation could be employed to describe the temperature dependence of the apparent diffusion coefficient (D_app) and the relaxation time (τ) of normalized scattering intensity at the early stage of spinodal decomposition (SD), as well as τ of phase behavior at the late stage of SD for the PS/PVME blend. The equilibrium phase-separation temperature could hardly be established through the conventional linear extrapolation of heating rate or D_app to zero at the early stage of SD. The successful use of the WLF-like function for PS/PVME blends extends the applicability of the time–temperature superposition principle for describing the phase-separation behavior of binary polymer mixtures over a relatively large temperature range. Copyright © 2010 Society of Chemical Industry

The stress relaxation of silica (SiO₂) filled solution-polymerized styrene–butadiene rubber (SSBR) has been investigated at shear strains located in the nonlinear viscoelastic regions. When the characteristic separability times are exceeded, the nonlinear shear relaxation modulus can be factorized into separate strain- and time-dependent functions. Moreover, the shear strain dependence of the damping function becomes strong with an increase in the SiO₂ volume fraction. On the other hand, a strain amplification factor related to nondeformable SiO₂ particles can be applied to account for the local strain of the rubbery matrix. Furthermore, it is believed that the damping function is a function of the localized deformation of the rubbery matrix independent of the SiO₂ content. The fact that the time–strain separability holds for both the unfilled SSBR and the filled compound indicates that the nonlinear relaxation is dominated by the rubbery matrix, and this implies that the presence of the particles can hardly qualitatively modify the dynamics of the polymer. It is thought that the filler–rubber interaction induces a coexistence of the filler network with the entanglement network of the rubbery phase, both being responsible for the nonlinear relaxation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

BACKGROUND: Hydrophobically modified polyelectrolytes are widely used polymers due to their good water solubility, stretched configuration in water and strong hydrophobic association. The study reported here aimed at researching the double action of hydrophobic association and electrostatic effect of novel hydrophobically modified polyelectrolytes in solution.

RESULTS: A series of novel hydrophobically modified polyelectrolytes were synthesized by micellar copolymerization with various feed ratios of sodium 2-acrylamido-2-methylpropanesulfonate, N-n-dodecylamine and sodium dodecylsulfonate. Their structure was characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance and gel permeation chromatography, and the viscosities of their aqueous and salt solutions were studied.

CONCLUSION: The results show that the addition of the hydrophobic comonomer results in a decrease in molecular weight (M_w). The smaller the initial number of hydrophobes in one micelle, the higher is M_w of the resulting copolymer. The viscosity of PAD-1.73 polyelectrolyte is less sensitive to salt than those of the others. According to the zero shear viscosity and corresponding concentration, the critical cluster-forming concentration, critical overlap concentration and critical entanglement concentration of these polymer solutions were determined. Moreover, in the dilute regime the viscosity decreases with increasing salinity, while in the semi-dilute regime the viscosity decreases first and then increases. It is suggested that in dilute and semi-dilute regimes, hydrophobic intramolecular association and intermolecular association dominate, respectively. Copyright © 2009 Society of Chemical Industry

A series of waterborne polyurethane dispersions (PUDs) were synthesized using castor oil, polypropylene glycol, toluene diisocyanate, and (2E)-4-(2,3-dihydroxypropoxy)-4-oxobut-2-enoic acid [glycol semi-ester (GSE)]. These PUDs can be crosslinked spontaneously upon drying, without extra additives or processing steps. Moreover, the rheological properties, particle size, and morphology of PUDs were examined with stress-controlled rheometer, light scattering ultrafine particle analyzer, and transmission electron microscopy. Results reveal that the particle size of PUDs mainly depends on the concentrations of castor oil, GSE, and polymer. With the increase of GSE concentration and the decrease of castor oil and polymer concentration, the particle size decreases. This can be ascribed to the decrease of the particle size of the polymer dispersion, because of the decrease of the relative size of water layer to total particle size. Furthermore, increased amount of castor oil, GSE, and polymer concentrations results in an increased viscosity of PUDs because of the increase of effective volume for the dispersed phase. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers

The conduction and viscoelastic responses to temperature are measured simultaneously for carbon black (CB) filled high-density polyethylene (HDPE) subjected to dynamic torsion. PTC/NTC transition was correlated with the loss tangent peak and the quasi modulus plateau, which was ascribed to the filler network. The bond-bending model of elastic percolation networks was used to reveal the structural mechanisms for the cyclic resistance changes at different temperatures. The resistance changes at lower temperatures depended on the deformation of the polymer matrix, while the changes in melting state were mainly attributed to the rearrangement of the CB network. A simple scaling law is derived to relate resistance and dynamic storage modulus in the melting region. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Room temperature resistance relaxation was studied with respect to carbon black (CB) volume fraction, the type of polymer matrix, and the environment. It was found that resistance of CB filled poly(methylvinylsiloxane) and polypropylene (PP) conductive composites changed at room temperature with different directions and amplitudes, depending on the filler volume fraction and the environment. The room temperature resistance relaxation was ascribed to the local Joule heat at the tunneling junction or the swelling effect of the solvents. On the other hand, CB filled immiscible PP/Nylon 1212 blends exhibited a stable electrical conduction due to the selective distribution of CB aggregates along the interface between polymer matrices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The linear viscoelastic behaviors of nylon1212 blends toughened with (styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer) (SEEPS) elastomer were carried out. The results show that dynamic storage modulus (G′) curves of the blends are located between those of virgin nylon and SEEPS within the frequency (ω) tested, and the G′ of blends increases with increasing of the SEEPS content. Moreover, the predictive results of Palierne emulsion model show that it is unsuitable for describing the viscoelastic behaviors of the double phase systems toughened with elastomer, especially for the system with high content of elastomer. The positive deviation in the plots of G′ vs. blend composition demonstrates that the blends are immiscible. From the point of phase transition, the phase inversion region for these blends was predicted to be in the range of 30–50 wt % of SEEPS, which agrees with the morphology analysis of nylon1212/SEEPS blends. In addition, “Cole–Cole” plots of modulus at different temperatures show that the microstructures of blends are unstable in the phase transition region. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The steady and dynamic rheological properties of hydroxyl-terminated polydimethylsiloxane filled with calcium carbonate were investigated by varying the filler volume fraction (Φ) from 0 to 18.2 vol %. The results reveal that there exists a “percolation threshold” (Φ_c = 3.6%) for the suspensions, below which both the “Cox-Merz” and modified “Cox-Merz” rule are competent over the whole shear regions. However, these two rules breakdown and a characteristic plateau appears in low frequency regions for suspensions with Φ > Φ_c. The reasons for this can be ascribed to the contributions of nonhydrodynamic forces and formation of percolated filler network structure with increasing Φ. Moreover, using a concentration-dependent parameter, B(Φ), superposition curves of dynamic complex modulus (|G*|) and shear stress (τ) for all suspensions were obtained through shifting |G*| curves along the ordinate and τ functions along the abscissa using different B(Φ) as shifting factor. Unfortunately, the reasonable superposition range is restricted in the high ω or regions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The rheological properties of silicone sealant filled with different calcium carbonate (CaCO₃) particles varying in size were investigated. It is found that as particle size decreases, the dynamic storage modulus (G′) and shear viscosity (η) increase; whereas, the width of linear viscoelastic region decreases. At low shear rate, a modulus plateau appears and the shear thinning behavior becomes apparent. The reasons for these can be ascribed to the enhanced particle–particle interaction and formation of filler network structure. Moreover, results dealing with the buildup of network structure monitored by kinetic recovery experiments reveal that both the rate of recovery and magnitude of rheological parameters increase with decreasing particle size. This phenomenon is consistent with the data collected from creep and recovery measurements, indicating an enhanced elasticity and network structure. Furthermore, transmission electron microscopy (TEM) observation and mechanical properties tests for cured sealant samples were also carried out to provide an evidence for the discussion further. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers

Two blends between polyamide 6 (PA6) and Polyamide 6co6T (PA6co6T, a random copolymer between polyamide 6 and polyamide 6T) were fabricated by melt-mixing on a twin-screw extruder and the subsequent injection molding, or through the in-situ polymerization of ε-caprolactam in the presence of PA6co6T. As far as the former method is concerned, there exist an obvious decline of toughness and a slight increase in strength and modulus; however, for the latter, there appear a remarkable improvement in toughness and a simultaneous moderate increase in strength and modulus. A series of characterizations were carried out including scanning electron microscopy, wide-angle X-ray diffraction, polarized optical microscopy, differential scanning calorimetry, dynamic mechanical analysis, and Fourier transform infrared spectrometry. It is found that both blends exhibit single glass transition on DMA tan δ curves. However, contrary to that of the melt-mixed blends, the glass transition temperature (T_g) of the in-situ ones decreases with increasing PA6co6T content. It is suggested that different mixing levels are the main reasons. Moreover, the addition of PA6co6T containing linear rigid segments conducts remarkable refinement of spherulites for the blends. Significantly different changes in the crystallographic form, spherulite size, crystalline content and perfection due to the introduction of PA6co6T for the two blends are ascribed to their varied thermomechanical histories and the presence of interchange reaction only for the in-situ blends. On the basis of the characterizations of the microstructures, the different trends of changes in the mechanical properties with the addition of PA6co6T for the two fabrication methods are discussed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 201–211, 2008