Pyrrole (Py)-based polyelectrolytes (Py-PE): P(Py-COOLi), P(Py-COONa), and P(Py-COOK) was synthesized, characterized, and used to prepare thin film resistive humidity sensors. Their humidity sensitive properties have been investigated, and sensing mechanism was presented. The Py-PE contains PPy as backbone and the side chain bearing carboxylic salt group, which made its sensor exhibited a very wide humidity sensing range of 0–97% relative humidity (RH), high conductivity even at very low humidity, and both ionic and electronic conduction contributed to its conductivity. Among all the Py-PE, P(Py-COOK) showed high sensitivity, with the impedance changing of about three orders of magnitude (103–106 Ω) from 97 to 0% RH, whereas P(Py-COONa) showed quick response for both absorption (12.5 s) and desorption (15.2 s). Py-PE prepared is promising for preparation of thin film resistive humidity sensors capable of detecting low humidity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Two novel alternating π-conjugated copolymers, named PDPPDOPV and PDPPDOPE, constituted of 1,4-diketo-3,6-diphenyl pyrrolo[3,4-c]pyrrole (DPP) with 2,5-dioctyloxy-1,4-phenylenevinylene (DOPV) or 2,5-dioctyloxy-1,4-phenyleneethynylene (DOPE), respectively, were synthesized and characterized by UV-vis, FT-IR, and photoluminescence spectroscopy. They are dark red solid readily soluble in various common organic solvents including THF and chloroform. The UV-vis absorption spectra of the polymers show strong absorption bands, which correspond to the π-π* transition of π-conjugated segments. Photoluminescence (PL) spectra show that both polymer films and solution have large Stokes shifts. From their fluorescence behavior, Stokes shifts of 173 nm and 199 nm are derived for the films of PDPPDOPV and PDPPDOPE, respectively, which are the largest two values ever reported for DPP-containing polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The application of Friedel-Crafts (FC) alkylation reaction to the in situ compatibilization between polystyrene-grafted nano-sized TiO2 (PS-grafted TiO2) and polypropylene (PP) was assessed. The PS-grafted TiO2 was first prepared via dispersion polymerization of styrene (St) using 3-(trimethoxysilyl) propyl methacrylate treated nano-sized TiO2 (MPS-treated TiO2) as cores, and then dispersed within PP by melt blending with different contents of FC catalyst, AlCl3/St, to give PP/PS-grafted TiO2 nanocomposites. The dispersion of PS-grafted TiO2 in PP and interfacial adhesion of PP/PS-grafted TiO2 nanocomposites were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The results indicated that the dispersion of PS-grafted TiO2 in PP could be improved, with an enhancement of interfacial adhesion between TiO2 and PP, by introducing FC catalyst with adequate concentration, which led to a better thermal stability and resistance to ultraviolet (UV) aging of PP/PS-grafted TiO2 nanocomposites. The effect of FC catalyst on the compatibilization between the PS-grafted TiO2 and PP was discussed based on FC alkylation reaction mechanism. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A novel calixarene-containing hyperbranched aliphatic polyester incorporated with pendant europium complexes (H20-Cal-Eu) was synthesized and characterized by FTIR, UV, and element analysis. The polymer H20-Cal-Eu shows a glass-transition temperature (Tg) of 127°C, and a deposition temperature in the range of 280–600°C, as revealed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The investigation on its photoluminescence (PL) properties revealed that the polymer emitted a remarkably strong red luminescence. Furthermore, its half spectral bandwidth of the polymer film is only about 10 nm as determined from luminescence spectra, suggesting that the light is nearly monochromatic. It is proposed that the hyperbranched polymer (HBP) containing rare earth element exhibits great potential as a red light emitting material. Copyright © 2009 John Wiley & Sons, Ltd.
Quaternized and salt-doped copolymer of 2-(dimethylamino) ethyl methacrylate (DMAEMA) with poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) was used to prepare resistive thin film humidity sensors. Their humidity sensitive properties have been characterized. The effects of the proportion of the comonomer and the amount of doped salt on the humidity sensitive properties of quaternized and salt-doped copolymer have been investigated. The humidity sensitive mechanisms of two different monomer structural units in the copolymer were discussed. The sensors based on the copolymers with different proportions of the comonomers exhibit a variety of conductivity and sensitivity for different humidities. Especially, the sensors exhibit high conductivity even at very low humidity. It is proposed that the good humidity sensitive properties are related to the introduction of salt-doped PEGMEMA in the copolymer. Copyright © 2009 John Wiley & Sons, Ltd.
A fluorescent hyperbranched copolymer (HTP) and a linear copolymer (PTP) as a reference sample to HTP both containing triphenylamine and divinyl bipyridyl units were synthesized via Heck coupling reaction from 5,5′-Divinyl-2,2′-bipyridyl with tris(4-bromophenyl)amine and with 4,4′-dibromotriphenylamie, respectively. The chemical structure of HTP was confirmed by FTIR, 1H NMR, and 13C NMR. The polymer HTP had a number-average molecular weight of 1895 and a weight-average molecular weight of 2315, and good solubility in conventional organic solvents, such as THF, DMF, and chloroform, and exhibited good thermal stability. The UV–vis absorption and photoluminescence (PL) spectra exhibited absorption maximum at 428 nm and emissive maximum at 531 nm for the HTP solution. The spectroscopic results of HTP and PTP indicated that hyperbranched conjugated structure increases the effective conjugation length, as compared with corresponding linear conjugated structure. The fluorescence of the polymer in solution can be quenched by various transition metal ions. The effect of backbone structure of the conjugated polymer-based chemosensors on the sensitivity and selectivity in metal ions sensing have been investigated, and the quenching effect of HTP is more sensitive toward transition metal than linear copolymer PTP. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 222–230, 2009
Poly(PEG200 maleate) was synthesized as a new type crosslinkable prepolymer and the semi-interpenetrating polymer network (semi-IPN) gel electrolytes were prepared by means of thermal polymerization. Their intrinsic properties were characterized by FTIR spectroscopy, differential scanning calorimetry (DSC), X-ray diffractions (XRD), scanning electron microscopy, alternating current impedance (AC impedance), and linear sweep voltammetry. The prepared polymer hosts are transparent and have good mechanical properties. The results of DSC and XRD confirm that the prepared hosts are in amorphous state and they can hold enough liquid electrolytes, which is favorable for Li+ ions to transport via both the absorbed liquid electrolyte and the gel of the entire systems. The semi-IPN gel electrolytes exhibit high ionic conductivity on the order of 10−3 S cm−1. Their electrochemical stability up to +4.6 V against Li+/Li also makes them potential candidates for application as polymer electrolytes in devices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
A new solid polymer electrolyte based on semi-interpenetrating polymer networks (semi-IPN) of crosslinked poly(glycidyl methacrylate-co-acrylonitrile)/poly(ethylene oxide) (P(GMA-co-AN)/PEO) was synthesized with diethylenetriamine (DETA) as the crosslinking agent and characterized. Fourier transform infrared spectroscopy (FTIR) spectra suggested the formation of semi-IPN structure by crosslinking and revealed the interactions of Li+ ions with both the ether oxygen in PEO chain and the nitrogen atom in AN segments. Differential scanning calorimetry (DSC) and X-ray diffraction pattern (XRD) measurements showed that crystallization of the semi-IPN polymer electrolyte was greatly impeded. Measurement of mechanical properties revealed that tensile strength of the polymer electrolyte was increased after crosslinking. Results of electrochemistry tests suggested that the new polymer electrolyte exhibited a high-ionic conductivity (10−4 S/cm) at room temperature, and an Arrhenius-like behavior of the conductivity was observed. And the semi-IPN polymer electrolyte with less content of PEO exhibited lower ion conductivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
A series of novel porphyrin-grafted poly (phenylene vinylene) derivatives, Porp-RO-PPV, were synthesized by a simple two-step method. These copolymers contain conjugated poly(phenylene vinylene) derivatives as polymer backbone and covalently linked porphyrin units as side chain, which were confirmed by FTIR and 1H NMR, and used for photovoltaic devices. The thermal, optical properties and sensitizing effect, and photovoltaic properties have been investigated. The emission spectra of Porp-RO-PPV copolymers revealed the existence of strong energy transfer from PPV backbone to porphyrin units. The energy conversion efficiency (ηe) of photovoltaic devices based on Porp-RO-PPV+PCBM reached 0.33% (78.2 mW/cm2, AM1.5) and porphyrin units in the copolymers showed good sensitizing effect at low concentration. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Humidity sensitive films with the structure of an interpenetrating network were prepared through simultaneous quaternization and crosslinking of poly(4-vinylpyridine) and poly(glycidyl methacrylate) with 1,4-dibromobutane and diethyltriamine, respectively, on the interdigital electrodes. The effect of the composition of humidity sensitive film and the concentration of dip-coating solution on the humidity sensitive properties of the sensors have been investigated. The humidity sensors so prepared exhibit little hysteresis (<1% RH [relative humidity]) and the response time for adsorption and desorption between 80% RH and 54% RH is about 21 s and 3 s, respectively, suggesting a very fast response. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
A new type dual-phase polymer electrolyte (DPE) based on poly(MMA-g-NBR) and poly(methyl methacrylate) (PMMA) was prepared by film-casting method. In the DPE, PMMA phase is selectively impregnated with the lithium salt solution, forming an ion-conducting network, while poly(MMA-g-NBR) phase maintains mechanical strength in the system. With grafting effect, the compatibility of two phases (PMMA/poly(MMA-g-NBR)) can be enhanced obviously. The chemical and physical characteristics, morphology and ionic conductivity behavior of DPEs, and their interfacial stability between lithium metal electrode were characterized by using of FTIR, 1HMNR, DSC, SEM, optical microscopic images, AC impedance, and linear sweep voltammetry. A new type DPE with good mechanics and high electrochemistry properties is obtained at an optimum proportion of two blending polymers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Functional poly[styrene-co-(2-ethylhexyl acrylate)-co-(1,6-hexanediol diacrylate)]/poly[(methyl methacrylate)-co-(butyl acrylate)-co-(methacrylic acid)-co-(diacetone acrylamide)] (PS/PA) semi-interpenetrating polymer networks (semi-LIPNs) containing ketone carboxyl groups were synthesized by two-stage emulsion polymerization, and characterized by Fourier transform infrared, transmission electron microscopy, dynamic light scattering and DSC. A unique feature of the PS/PA semi-LIPNs is their ability to crosslink and form thermosetting full-IPN polymers through the reaction of ketone carboxyl and hydrazide in the course of film formation at ambient temperatures. Series of latex particles with various levels of crosslinking density in the PS and PA domain and varied composition of PS/PA LIPNs were obtained. The effects of the LIPN PS/PA composition and the level of crosslinking density in the PS and PA domain on film density, swell ratio, mechanical properties and contact angle with water were investigated. Maximum synergy effects obtained at around 50/50 (PS/PA) in terms of mechanical properties, density and contact angle with water indicate that the maximum degree of interpenetration is obtained at this composition. Copyright © 2006 Society of Chemical Industry
