Variable‐emittance infrared electrochromic skins combining unique conducting polymers,ionic liquid electrolytes,microporous polymer membranes,and semiconductor/polymer coatings,for spacecraft thermal control

Variable emittance (ε) is a property vital for the increasing needs in thermal control of future microspacecraft. This article describes fabrication, function, and performance of thin‐film, flexible, variable‐emittance (V‐E) electrochromic skins that use a conducting polymer/‐Au/‐microporous membrane (CP/Au/µP) base, and a new, unique ionic liquid electrolyte (IonEl). Poly(aniline‐co‐diphenyl amine) with a long‐chain polymeric dopant is used as the CP. A unique, patented device design yields no barrier between the active, electrochromic CP surface and the external environment, except for a thin, infrared‐transparent semiconductor/polymer film that lowers solar absorptance [α(s)] and protects from atomic‐O/far‐UV. Use of the IonEl requires special activation methods. Data presented show tailorable ε variations from 0.19 to 0.90, Δε values of >0.50 (which is the highest reported thus far for any functional V‐E material, to our knowledge), α(s) < 0.35, and nearly indefinite cyclability. Extended space durability testing, including calorimetric thermal vacuum and continuous light/dark cycling over >7 months under space conditions (<10^?5 Pa vacuum, far‐UV), show excellent durability. Other data show resistance to solar wind, atomic‐O, electrostatic discharge, and micrometeoroids. These lightweight, inexpensive, advanced polymeric materials represent the only technology that can work with micro‐ (<20 kg) and nano‐ (<2 kg) spacecraft, thus eventually allowing for much greater flexibility in their design and potentially “democratizing” the entire space industry, for example, allowing small firms to launch their own, dedicated satellites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40850.     

Smart sunglasses based on electrochromic polymers

Smart sunglasses based on electrochromic polymers are proposed and developed in this study. This article discusses the design, processing, and the optical and electrical performance of a prototype smart sunglasses based on cathodic electrochromic (EC) polymers, which show several merits compared with traditional materials for sunglasses lens as well as other smart window materials. It is a multilayer design of device. The conjugated polymer, poly[3,3‐dimethyl‐3,4‐dihydro‐2H‐thieno [3,4‐b] [1,4]dioxepine] (PProDOT‐Me₂), is utilized as the electrochromic working layer. The counter layer of the device is vanadium oxide (V₂O₅) film, which serves as an ion storage layer. There is also a polymer gel electrolyte acting as the ionic transport layer, sandwiched between the working and counter layers. The characteristics of the prototype device are reported, including transmittance (%T), driving power, response time, open circuit memory, and lifetime. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Electrochemical synthesis and In situ spectroelectrochemistry of conducting NMPy‐TiO2 and ZnO polymer nanocomposites for Li secondary battery applications

Poly(N‐methylpyrrole) (PNMPy), poly(N‐methylpyrrole‐TiO₂) (PNMPy‐TiO₂), and poly (N‐methylpyrrole‐ZnO) (PNMPy‐ZnO) nanocomposites were synthesized by in situ electropolymerization for cathode active material of lithium secondary batteries. The charge–discharging behavior of a Li/LiClO₄/PNMPy battery was studied and compared with Li/LiClO₄/PNMPy‐nanocomposite batteries. The nanocomposites and PNMPy films were characterized by cyclic voltammetry, in situ resistivity measurements, in situ UV–visible, and Fourier transform infra‐red (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The differences between redox couples (ΔE) were obtained for polymer nanocomposites and PNMPy films. During redox scan, a negative shift of potential was observed for polymer nanocomposite films. Significant differences from in situ resistivity of nanocomposites and PNMPy films were obtained. The in situ UV–visible spectra for PNMPy and polymer nanocomposite films show the intermediate spectroscopic behavior between polymer nanocomposites and PNMPy films. The FTIR peaks of polymer nanocomposite films were found to shift to higher wavelengths in PNMPy films. The SEM and TEM micrographs of nanocomposite films show the presence of nanoparticle in PNMPy backbone clearly. The result suggests that the inorganic semiconductor particles were incorporated in organic conducting PNMPy, which consequently modifies the properties and morphology of the film significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41526.     

UV‐initiated copolymerization route for facile fabrication of epoxy‐functionalized micro‐zone plates

Bisphenol A‐based epoxy acrylate (BABEA), a commercial ultraviolet (UV)‐curable material, was introduced as a new manufacturing material for facile fabrication of epoxy‐functionalized micro‐zone plates through UV‐initiated copolymerization using glycidyl methacrylate (GMA) as the functional monomer. The poly (BABEA‐co‐GMA) was highly transparent in visible range while highly opaque when the wavelength is less than 295 nm, and of high replication fidelity. X‐ray photoelectron spectroscope (XPS) results indicated the existence of epoxy groups on the surface of the poly (BABEA‐co‐GMA), which allowed for binding protein through an epoxy‐amino group reaction. A fabrication procedure was proposed for manufacturing BABEA based epoxy‐functionalized micro‐zone plates. The fabrication procedure was very simple; obviating the need of micromachining equipments, wet etching or imprinting techniques. To evaluate the BABEA‐based epoxy‐functionalized micro‐zone plates, α‐fetoprotein (AFP) was immobilized onto the capture zone for chemiluminescent (CL) detection in a noncompetitive immune response format. The proposed AFP immunoaffinity micro‐zone plate was demonstrated as a low cost, flexible, homogeneous, and stable assay for α‐fetoprotein (AFP). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39787.     

Specroelectrochemical,switching kinetics,and chronoamperometric studies of dibenzyl derivative of poly(3,4‐propylenedioxythiophene) thin‐film‐based electrochromic device

The dibenzyl derivative of poly(3,4‐propylenedioxythiophene) (PProDOT‐Bz₂) thin film is deposited onto ITO‐coated glass substrate by electropolymerization technique. The electropolymerization of ProDOT‐Bz₂ is carried out by a three‐electrode electrochemical cell. The cyclic voltammogram shows the redox properties of electrochemically prepared films deposited at different scan rates. The thin films prepared were characterized for its morphological properties to study the homogeniety. Classic six‐layer structure of PProDOT‐Bz₂ electrochromic device using this material was fabricated and reported for the first and its characterizations such as spectroelectrochemical, switching kinetics, and chronoamperometric studies are performed. The color contrast of the thin film and the device achieved are 64 and 40%, respectively, at λ_max (628 nm). The switching time is recorded and the observed values are 5 s from the coloring state to the bleaching state and vice versa. The chronoamperometry shows that the device performed up to 400 cycles, and it is capable of working up to 35 cycles without any degradation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40717.     

Quinone propionic acid‐based redox‐triggered polymer nanoparticles for drug delivery: Computational analysis and in vitro evaluation

Redox‐responsive polymers with pendant quinone propionic acid groups as a redox trigger were optimized by computational modeling to prepare efficient redox‐triggered polymer nanoparticles (NPs) for drug delivery. Lipophilicities at complete reduction of redox‐responsive polymers (<5000 Da) constructed with adipic acid and glutaric acid were remarkably reduced to range from ?6.29 to ?0.39 compared with nonreduced state (18.87–32.46), suggesting substantial polymer solubility reversal in water. Based on this hypothesis, redox‐responsive NPs were prepared from the synthesized polymers with paclitaxel as model cancer drug. The average size of paclitaxel‐loaded NPs was 249.8 nm and their reconstitutions were stable over eight weeks. In vitro drug release profiles demonstrated the NPs to release >80% of paclitaxel over 24 h at a simulated redox‐state compared with 26.5 to 41.2% release from the control. Cell viability studies revealed that the polymer was nontoxic and the NPs could release paclitaxel to suppress breast cancer cell growth. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40461.     

Electropolymerization of a new 4‐(2,5‐Di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl)‐tetra substituted nickel phthalocyanine derivative

A new tetrakis 4‐(2,5‐di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl) substituted nickel phthalocyanine (NiPc‐SNS) was synthesized and characterized by elemental analysis, Fourier Transform Infrared (FT‐IR), and UV–vis spectroscopies. The electrochemical polymerization of this newly synthesized NiPc‐SNS was performed in dichloromethane (DCM)/tetrabutylammonium perchlorate (TBAP) solvent/electrolyte couple. An insoluble film was deposited on the electrode surface, both during repetitive cycling and constant potential electrolysis at 0.85 V. Resulting polymer film, P(NiPc‐SNS), was characterized utilizing UV–vis and FT‐IR spectroscopic techniques and its electrochemical behavior was investigated via cyclic voltammetry (CV). Spectroelectrochemical behavior of the polymer film on indium tin oxide (ITO) working electrode was investigated by recording the electronic absorption spectra, in situ, in monomer‐free electrolytic solution at different potentials and it is found that the P(NiPc‐SNS) film can be reversibly cycled between 0.0 and 1.1 V and exhibits electrochromic behavior; dark olive green in the neutral and dark blue in the oxidized states with a switching time of 1.98 s. Furthermore, the band gap of P(NiPc‐SNS) was calculated as 2.27 eV from the onset of π–π* transition of the conjugated backbone. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Plasmon‐enhanced,two‐photon absorption in Schiff‐base‐modified poly(styrene‐co‐maleic anhydride)–gold nanocomposites

Poly(styrene‐co‐maleic anhydride) (SMA) is a synthetic copolymer with interesting thermal and membrane properties. Schiff bases are one of the most widely used organic compounds with chelating ligands having N, S, and O as donor atoms. A Schiff‐base‐modified SMA was synthesized by the reaction of the copolymer with salicylaldehyde thiosemicarbazone. Gold (Au) nanoparticles (NPs), synthesized by a citrate reduction method were used to prepare the polymer–Au nanocomposites. In this research, we explored and investigated the effects on the linear and nonlinear optical properties of the Schiff‐base‐modified SMA copolymer with the incorporation of Au NPs. Open‐aperture Z‐scan measurements were recorded for the polymer, modified polymer, and polymer–Au nanocomposites at 532 nm with an Nd:YAG laser with a repetition rate of 10 Hz and a pulse width of 5 ns. The results indicate that the addition of the Au NPs effectively enhanced the two‐photon absorption coefficients of the polymer and, thereby, provided a platform for the development of nonlinear optical devices with good optical‐limiting properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45377.     

Synthesis and characterization of poly(thiophen‐3‐yl acetic acid 4‐pyrrol‐1‐yl phenyl ester‐co‐N‐methylpyrrole) and its application in an electrochromic device

Copolymer of thiophen‐3‐yl acetic acid 4‐pyrrol‐1‐yl phenyl ester (TAPE) with N‐methylpyrrole (NMPy) was synthesized by potentiostatic electrochemical polymerization in acetonitrile–tetrabutylammonium tetrafluoroborate solvent–electrolyte couple. The chemical structures were confirmed via Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and UV–vis spectroscopy. Electrochromic and spectroelectrochemical properties of poly(TAPE‐co‐NMPy) [P(TAPE‐co‐NMPy)] were investigated. Results showed that the copolymer revealed color change between light yellow and green upon doping and dedoping of the copolymer, with a moderate switching time. Furthermore, as an application, dual‐type absorptive/transmissive polymer electrochromic device (ECD) based on poly(TAPE‐co‐NMPy) and poly(3,4‐ethylene dioxythiophene) (PEDOT) have been assembled, where spectroelectrochemistry, switching ability, stability, and optical memory of the ECD were investigated. Results showed that the device exhibited good optical memory and stability with moderate switching time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1988–1994, 2006     

Synthesis and solar cells applications of EO‐PF‐DTBT polymer

Poly{[2,7‐(9,9‐bis‐(1‐(2‐(2‐methoxyethoxy)ethoxy)ethyl)‐fluorene)]‐alt‐[5,5‐(4,7‐di‐2′‐thienyl‐2,1,3‐benzothiadiazole)]} (EO‐PF‐DTBT) was synthesized by Suzuki coupling reaction. The polymer is soluble in common organic solvent, such as toluene, THF, and chloroform, and it also shows solubility in polar solvent, such as cyclopentanone. Solar cells based on EO‐PF‐DTBT and PC₆₁BM show maximum power conversion efficiency of 2.65% with an open circuit voltage (V_OC) of 0.86 V, a short circuit current density (J_SC) of 6.10 mA/cm², and a fill factor of 51% under AM 1.5G illumination at 100 mW/cm², which is the best results for fluorene and 4,7‐di‐2‐thienyl‐2,1,3‐benzothiadiazole copolymers and PC₆₁BM blend. The 1,8‐diiodooctane can work well to reduce the over‐aggregated phase structure in polymer solar cells. Our results suggest that the introducing high hydrophilic side chain into conjugated polymer donor materials can tune the aggregation structure and improve the solar cells performances. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40478.     

Preparation of dual‐layer acetylated methyl cellulose hollow fiber membranes via co‐extrusion using thermally induced phase separation and non‐solvent induced phase separation methods

Dual‐layer acetylated methyl cellulose (AMC) hollow fiber membranes were prepared by coupling the thermally induced phase separation (TIPS) and non‐solvent induced phase separation (NIPS) methods through a co‐extrusion process. The TIPS layer was optimized by investigating the effects of coagulant composition on morphology and tensile strength. The solvent in the aqueous coagulation bath caused both delayed liquid–liquid demixing and decreased polymer concentration at the membrane surface, leading to porous structure. The addition of an additive (triethylene glycol, (TEG)) to the NIPS solution resolved the adhesion instability problem of the TIPS and NIPS layers, which occurred due to the different phase separation rates. The dual‐layer AMC membrane showed good mechanical strength and performance. Comparison of the fouling resistance of the AMC membranes with dual‐layer polyvinylidene fluoride (PVDF) hollow fiber membranes fabricated with the same method revealed less fouling of the AMC than the PVDF hollow fiber membrane. This study demonstrated that a dual‐layer AMC membrane with good mechanical strength, performance, and fouling resistance can be successfully fabricated by a one‐step process of TIPS and NIPS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42715.     

Characteristics of dual‐type electrochromic devices based on poly(ethylene oxide) copolymers

Dual‐type polymer electrochromic devices based on [(3‐thienyl)methylmethacrylate]‐co‐[p‐vinyl benzyloxy poly(ethylene oxide)]/polythiophene and thiophene‐capped poly(ethylene oxide)/polythiophene and ethylene dioxythiophene were constructed via electropolymerization. Spectroelectrochemistry, switching ability and stability of the devices were investigated using UV‐visible spectrophotometry and cyclic voltammetry. These devices exhibit low switching voltages and short switching times with reasonable switching stability under atmospheric conditions. Copyright © 2006 Society of Chemical Industry     

Thermosensitive self‐assembly micelles from A2BA2‐type poly(N‐isopropyl acrylamide)2‐b‐Poly(lactic acid)‐b‐Poly(N‐isopropyl acrylamide)2 four‐armed star block copolymers and their applications as drug carriers

A novel A₂BA₂‐type thermosensitive four‐armed star block copolymer, poly(N‐isopropyl acrylamide)₂‐b‐poly(lactic acid)‐b‐poly(N‐isopropyl acrylamide)₂, was synthesized by atom transfer radical polymerization and characterized by ¹H‐NMR, Fourier transform infrared spectroscopy, and size exclusion chromatography. The copolymers can self‐assemble into nanoscale spherical core–shell micelles. Dynamic light scattering, surface tension, and ultraviolet–visible determination revealed that the micelles had hydrodynamic diameters (D_h) below 200 nm, critical micelle concentrations from 50 to 55 mg/L, ζ potentials from ?7 to ?19 mV, and cloud points (CPs) of 34–36°C, depending on the [Monomer]/[Macroinitiator] ratios. The CPs and ζ potential absolute values were slightly decreased in simulated physiological media, whereas D_h increased somewhat. The hydrophobic camptothecin (CPT) was entrapped in polymer micelles to investigate the thermo‐induced drug release. The stability of the CPT‐loaded micelles was evaluated by changes in the CPT contents loaded in the micelles and micellar sizes. The MTT cell viability was used to validate the biocompatibility of the developed copolymer micelle aggregates. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4137–4146, 2013     

Synthesis and spectroelectrochemistry of dithieno(3,2‐b:2′,3′‐d)pyrrole derivatives

New π‐conjugated polymers containing dithieno(3,2‐b:2′,3′‐d)pyrrole (DTP) were successfully synthesized via electropolymerization. The effect of structural differences on the electrochemical and optoelectronic properties of the 4‐[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl]aniline (DTP–aryl–NH₂), 10‐[4H‐dithiyeno(3,2‐b:2′,3′‐d)pirol‐4‐il]dekan‐1‐amine (DTP–alkyl–NH₂), and 1,10‐bis[4H‐dithieno(3,2‐b:2′,3′‐d)pyrrol‐4‐yl] decane (DTP–alkyl–DTP) were investigated. The corresponding polymers were characterized by cyclic voltammetry, NMR (¹H‐NMR and ¹³C‐NMR), and ultraviolet–visible spectroscopy. Changes in the electronic nature of the functional groups led to variations in the electrochemical properties of the π‐conjugated systems. The electroactive polymer films revealed redox couples and exhibited electrochromic behavior. The replacement of the DTP–alkyl–DTP unit with DTP–aryl–NH₂ and DTP–alkyl–NH₂ resulted in a lower oxidation potential. Both the poly(10‐(4H‐Dithiyeno[3,2‐b:2′,3′‐d]pirol‐4‐il)dekan‐1‐amin) (poly(DTP–alkyl–NH₂)) and poly(1,10‐bis(4H‐dithieno[3,2‐b:2′,3′‐d]pyrrol‐4‐yl) decane) (poly(DTP–alkyl–DTP)) films showed multicolor electrochromism and also fast switching times (<1 s) in the visible and near infrared regions. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40701.     

Temperature‐ and pH‐sensitive IPNs grafted onto polyurethane by gamma radiation for antimicrobial drug‐eluting insertable devices

Temperature‐ and pH‐sensitive interpenetrating polymer networks (IPNs) and semi‐interpenetrating polymer networks (s‐IPNs) were γ‐ray grafted onto polyurethane (Tecoflex^®; TFX) to obtain vancomycin‐eluting implantable medical devices with minimized risk of infections. N‐isopropylacrylamide (NIPAAm) was grafted onto TFX catheters and films via a preirradiation oxidative method (method P) or via a direct method (method D). The PNIPAAm network facilitated acrylic acid (AAc) inclusion and subsequent polymerization/crosslinking, under specific reaction conditions. IPNs and s‐IPNs systems were characterized regarding the amount of grafted polymers, surface properties (FTIR‐ATR, ESEM, EDX), thermal behavior (DSC), and their temperature‐ and pH‐responsiveness. Loading and release of vancomycin for preventing in vitro growth of Staphylococcus aureus were also evaluated. Antimicrobial activity tests and hemo‐ (hemolysis, protein adsorption, thrombogenicity) and cyto‐compatibility (cell viability and production of cytokines and NO) assays indicated that the modification of TFX by γ‐radiation may improve the performance of polyurethanes for biomedical applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39992.     

Sensing and surface morphological properties of a poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐bithiophene] liquid‐crystalline polymer for optoelectronic applications

The sensing properties of a poly[(9,9‐dioctylfluorenyl‐2,7‐diyl)‐co‐bithiophene] (F8T2) polymer were investigated at different concentrations and volume percentages. The effects of the concentrations and volume percentages on the sensing parameters were investigated. The sensitivities of F8T2 were found to be 3.190, 1.434, and 0.362 dB/vol % at 290, 580, and 940 nm, respectively. The response of the F8T2 increased with increasing concentration. F8T2 exhibited good sensitivity and response behaviors. Then, the optical parameters based on the refractive indices of the F8T2 at different molarities were calculated. The dispersion energy, moment of the dielectric constant optical spectrum (M_?1, M_?3), oscillator strength, and contrast of the F8T2 increased with increasing molarity, whereas the average excitation energy or single‐oscillator energy decreased with increasing molarity. The surface morphological properties of the F8T2 polymer film were investigated, and the roughness parameters were obtained. The F8T2 polymer could be used in the fabrication of various sensors because of the good solubility, sensitivity, and response behaviors. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41659.     

Preparation and photocurrent generation of an electrostatically self‐assembled film of hemicyanine and poly(4‐styrenesulfonic acid‐co‐maleic acid)

In this article, we report on electrostatically self‐assembled thin films prepared by the alternative immersion of quartz‐coated and indium tin oxide coated glass substrates in aqueous solutions of a copolymer of poly(4‐styrenesulfonic acid‐co‐maleic acid) (PSSMA) and a hemicyanine of (E)?1,1′‐(propane‐1,3‐diyl)bis{4‐[4‐(dimethylamino)styryl]pyridinium} bromide (H³Br₂). The films were studied by means of ultraviolet–visible absorption and X‐ray photoelectron spectroscopies, scanning electron microscopy, and photoelectrochemical measurements. When irradiated with white light, the PSSMA/H³ monolayer film gave a stable cathodic photocurrent. The effects of the applied bias voltages, layer numbers of the (PSSMA/H³)_n films (where n stands for the number of bilayer films on both sides of the substrates), light intensities, pH value, and electron acceptor on the photocurrent generation of the (PSSMA/H³)_n film were examined. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39871.     

Electrochromic properties of a copolymer of 1‐4‐di[2,5‐di(2‐thienyl)‐1H‐1‐pyrrolyl]benzene with EDOT

Homopolymer of 1‐4‐di[2,5‐di(2‐thienyl)‐1H‐1‐pyrrolyl]benzene and its copolymer with 3,4‐ethylenedioxythiophene (EDOT) were electrochemically synthesized and characterized. Resulting homopolymer and copolymer films have distinct electrochromic properties. At the neutral state, homopolymer has λ_max due to the π‐π* transition as 410 nm and E_g was calculated as 2.03 eV. The resultant copolymer revealed multichromism through the entire visible region, displaying red‐violet, brownish yellow green, and blue colors with the variation of the applied potential. For the copolymer, λ_max and E_g were found to be 450 nm and 1.66 eV, respectively. Double potential step chronoamperometry experiment shows that homopolymer and copolymer films have good stability, fast switching times, and high optical contrast in NIR region as 41 and 30%, respectively. Copolymerization with EDOT not only decreases the band gap, E_g, but also enhances the electrochromic properties. Hence, electrochemical copolymerization is considered to be a powerful tool to improve the electrochromic properties of N‐substituted 2,5‐di(2‐thienylpyrrole) derivatives. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Deep‐black‐coloring effect of fabrics made of noncircular cross‐section polyester filaments

The effects of noncircular cross‐section (NCCS) poly ethylene terephthalate (PET) filaments and its shape factor on deep‐black‐coloring of dyed fabrics were investigated by comparing to that of the circular cross‐section PET ones. Indexes such as K/S, L* and Integ values were used for characterizing the deep‐black‐coloring effect on fabrics. The results indicated that fabrics made with NCCS PET filaments exhibited good deep‐black‐coloring effects. The calculated shape factor of the NCCS PET fiber had a significant correlation with the degree of deep‐black‐coloring exhibited by the fabric made from the fibers. A qualitative optical analysis of the NCCS PET fibers was carried out to explain the causes of the deep‐coloring of the NCCS fibers. This analysis implies that the contours of the NCCS fiber composed of surfaces with varied curvature increase the scattering of light by lowering specular reflection and increasing interior reflected and refracted light. This, in turn, strengthens the deep‐coloring effect. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 511–518, 2014     

Dynamic properties of star‐shaped,solution‐polymerized styrene–butadiene rubber and its cocoagulated rubber‐filled with silica/carbon black

The dynamic properties, including the dynamic mechanical properties, flex fatigue properties, dynamic compression properties, and rolling loss properties, of star‐shaped solution‐polymerized styrene–butadiene rubber (SSBR) and organically modified nanosilica powder/star‐shaped styrene–butadiene rubber cocoagulated rubber (N‐SSBR), both filled with silica/carbon black (CB), were studied. N‐SSBR was characterized by ¹H‐NMR, gel permeation chromatography, energy dispersive spectrometry, and transmission electron microscopy. The results show that the silica particles were homogeneously dispersed in the N‐SSBR matrix. In addition, the N‐SSBR/SiO₂/CB–rubber compounds' high bound rubber contents implied good filler–polymer interactions. Compared with SSBR filled with silica/CB, the N‐SSBR filled with these fillers exhibited better flex fatigue resistance and a lower Payne effect, internal friction loss, compression permanent set, compression heat buildup, and power loss. The nanocomposites with excellent flex fatigue resistance showed several characteristics of branched, thick, rough, homogeneously distributed cross‐sectional cracks, tortuous flex crack paths, few stress concentration points, and obscure interfaces with the matrix. Accordingly, N‐SSBR would be an ideal matrix for applications in the tread of green tires. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40348.