Preparation of conducting nylon‐6 electrospun fiber webs by the in situ polymerization of polyaniline

For the preparation of conducting polyaniline (PANI)/nylon composites with high electrical conductivity as well as superior mechanical properties such as flexibility and lightness, PANI/nylon‐6 composite nanofiber webs were prepared via the electrospinning process with a nylon‐6/formic acid polymer solution, and then PANI on the surface of the nylon‐6 electrospun nanofiber webs was chemically polymerized. The electrical conductivity measurements showed that the conductivity of the PANI/nylon‐6 composite electrospun fiber webs was superior to that of PANI/nylon‐6 plain‐weave fabrics because of the high surface‐area/volume ratios. On the other hand, the volume conductivities of the PANI/nylon‐6 composite electrospun fiber webs increased from 0.5 to 1.5 S/cm as the diffusion time increased from 10 min to 4 h because of the even distribution of PANI in the electrospun fiber webs. However, the surface conductivities of the PANI/nylon‐6 composite electrospun fiber webs somewhat decreased from 0.22 to 0.14 S/cm as the diffusion time increased because of PANI contaminated with aniline monomers, aniline oligomers, and some alkyl chains, which served as electrical resistants. These results were confirmed with Fourier transform infrared, electron spectroscopy for chemical analysis, and morphology analysis. It was concluded that the diffusion time for the in situ polymerization of PANI in electrospun fiber webs was optimized at approximately 3 h. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 983–991, 2005     

Effect of dopant mixture on the conductivity and thermal stability of polyaniline/nomex conductive fabric

Electrically conductive polyaniline (PANI)/[poly(m‐phenylene isophthalamide)] Nomex composite fabric was prepared by in situ polymerization of aniline doped by a mixture of hydrochloride (HCl) and various sulfonic acids such as benzenesulfonic acid (BSA), sulfosalicylic acid (SSA), and dodecylbenesulfonic acid (DBSA); their effect on conductivity and physical properties were then investigated. PANI/Nomex composite fabrics doped by a mixture of protonic acids exhibited higher conductivity than those doped by other single dopants such as camphorsulfonic acid (CSA), p‐toluenesulfonic acid (TSA), BSA, SSA, and HCl. The conductivity of PANI/Nomex fabrics especially doped by a mixture of HCl and DBSA was evenly maintained up to 100°C without depression of mechanical properties of Nomex. Their conductivity was also maintained under extension of the composite fabric. In addition, electrical conductivity of PANI/Nomex fabrics was highly increased by ultrasonic treatment, which facilitated better diffusion and adsorption of aniline by cavitation and vibration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2245–2254, 2002     

Electrochemically synthesized polypyrrole and Cu‐plated nylon/spandex for electrotherapeutic pad electrode

Electroconductive fabrics were prepared to improve the properties of conductive electrode pad material used for electrotherapy when it is subjected to various movements of the human body. Highly stretchable and conductive fabrics were prepared by in situ electrochemical polymerization of polypyrrole (PPy) on nylon/spandex stretchable fabric in aqueous solutions with 0.05M pyrrole and 0.05M anthraquinone‐2‐sulfonic acid, sodium salt monohydrate (AQSA) at room temperature for 2 h. Electroless Cu plating was also applied after chemical polymerization of PPy to improve the conductivity of the fabric pad. Performance of prepared stretchable conductive fabric pad was evaluated in terms of conductivity changes as a function of extension and continuous current application time, and clinical test. As a result, the fabric conductivity was well maintained with extension up to 60% and prolonged treatment time over 30 min. The effect of transcutaneous electrical nerve stimulation (TENS) was observed with prepared TENS pad in this study and conventional TENS pad for medical use. The significant effect of TENS was observed with a pad made of conductive fabric by Cu plating and a conventional TENS pad (P < 0.05, respectively). Even though the efficiency of an experimental pad made of fabric composite with electrochemically polymerized PPy was not as good as conventional TENS pad for medical use in this experiment, it can possibly be used for other applications where relatively low‐strength electrical pulse is required. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 4064–4071, 2004     

Melting,crystallization behaviors,and nonisothermal crystallization kinetics of PET/PTT/PBT ternary blends

The melting, crystallization behaviors, and nonisothermal crystallization kinetics of the ternary blends composed of poly(ethylene terephthalate), poly(trimethylene terephthalate) (PTT) and poly(buthylene terephthalate) (PBT) were studied with differential scanning calorimeter (DSC). PBT content in all ternary blends was settled invariably to be one‐third, which improved the melt‐crystallization temperature of the ternary blends. All of the blend compositions in amorphous state were miscible as evidenced by a single, composition‐dependent glass transition temperature (T_g) observed in DSC curves. DSC melting thermograms of different blends showed different multiple melting and crystallization peaks because of their various polymer contents. During melt‐crystallization process, three components in blends crystallized simultaneously to form mixed crystals or separated crystals depending upon their content ratio. The Avrami equation modified by Jeziorny and the Ozawa theory were employed to describe the nonisothermal crystallization process of two selected ternary blends. The results spoke that the Avrami equation was successful in describing the nonisothermal crystallization process of the ternary blends. The values of the t_1/2 and the parameters Z_c showed that the crystallization rate of the ternary blends with more poly(ethylene terephthalate) content was faster than that with the lesser one at a given cooling rate. The crystal morphology of the five ternary blends investigated by polarized optical microscopy (POM) showed different size and distortional Maltese crosses or light spots when the PTT or poly(ethylene terephthalate) component varied, suggesting that the more the PTT content, the larger crystallites formed in ternary blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Preparation and characterization of graphene composites with conducting polymers

We report a new route for preparing electro‐conductive composites based on reduced graphene oxide (RG‐O) and poly(3,4‐ethylenedioxythiophene) (PEDOT). The composites were prepared by in situ polymerization of EDOT in aqueous mixture containing RG‐O platelets modified with poly(sodium 4‐styrenesulfonate) (PSS). In the synthetic process, PSS molecules stabilize RG‐O in the aqueous phase and function as a polymerization template to hybridize PEDOT chains along RG‐O platelets. Compared with the RG‐O platelets, the resulting composites show an enhanced electrical conductivity of 9.2 S cm^?1 with good thermal stability. Copyright © 2011 Society of Chemical Industry     

Electrically conductive textiles by in situ polymerization of aniline

Two methods of obtaining electrically conductive fabrics by in situ polymerization of aniline were compared. Conductive fabrics were prepared by immersing the nylon 6 fabrics in 100% aniline or an aqueous hydrochloride solution of aniline followed by initiating successive polymerization in a separate bath (DPSB) or in a mixed bath (DPMB) of oxidant and dopant solution with aniline. In each case, the polymerization conditions were optimized to obtain the maximum quality of polyaniline (PAn) on the fabrics. The higher conductivity of composite fabrics, whose value reached up to 0.6 × 10⁻¹ s/cm, was obtained by the DPMB process. Moreover, this method induced the least decrease in the degree of crystallinity as compared to the DPSB process. The serviceability of the PAn–nylon 6 composite fabrics was also evaluated. No significant changes in the conductivity were observed after abrading the composite fabrics over 50 cycles and multiple acid and alkali treatment. The stability of conductivity was slightly decreased by less than 1 order after exposure to light for 100 h, but it was significantly decreased after washing with detergent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2094–2101, 1999     

Crystallization behavior and morphology of double crystalline poly(trimethylene terephthalate)/poly(ethylene oxide terephthalate) copolymers

Double crystalline poly(trimethylene terephthalate)/poly(ethylene oxide terephthalate) copolymers (PTT/PEOT), with PTT content ranging from 16.5 to 65.5 wt%, were synthesized by melt copolycondensation. The morphological transformation of samples from microphase separation to macrophase separation was investigated by gel permeation chromatography and transmission electron microscopy. Differential scanning calorimetry and in situ wide‐angle X‐ray diffraction suggested that all copolycondensation samples displayed double crystalline behavior. The melt‐crystallization peak temperatures (T_{m, c} values) of PTT chains monotonously increased with increasing PTT content and were higher than that of homo‐PTT when the content of PTT was above 30.6 wt%. Interestingly, T_{m, c} values of PEOT chains were also increased with increasing PTT content. Polarized optical microscopy revealed that all copolycondensation samples studied could form ring‐banded spherulites and band spacing increased with increasing T_c values. In addition, band spacing decreased with increasing PTT content at a given T_c. Strangely, although PEOT was the main component in all copolycondensation samples, spherulitic morphology formed by the advance crystallization of PTT did not change after PEOT crystallization. Only a subtle change of quadrant tones was detected. © 2012 Society of Chemical Industry     

Thermal decomposition kinetics of thermotropic poly(oxybenzoate‐co‐trimethylene terephthalate)

A new kind of thermotropic liquid crystalline, poly(oxybenzoate‐co‐trimethylene terephthalate), was prepared from p‐hydroxybenzoic acid (B) and poly(trimethylene terephthalate) (PTT or T) by melting polycondensation. The monomer ratio of B to T is 60:40. The dynamic thermogravimetric kinetics of the copolymer B/T (60:40) and PTT in nitrogen were analyzed by four single heating rate techniques and two multiple heating rate techniques. The effects of the heating rate and the calculating technique on the thermostable and degradation kinetic parameters of the B/T copolymer and PTT are systematically discussed. The four single heating rate techniques used in this work include Friedman, Freeman‐Carroll, Chang, and the second Kissinger techniques, whereas the two multiple heating rate techniques are the first Kissinger and Flynn‐Wall techniques. Additionally, the isothermal thermogravimetric kinetics of B/T (60:40) in nitrogen were investigated by the Flynn technique. The activation energy, the order, and the frequency factor of the degradation reaction for B/T (60:40) copolymer are determined to be 185 kJ/mol, 1.8, and 7.14 × 10¹³ min⁻¹, respectively. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2025–2036, 2000     

In situ polymerization of aniline on acrylamide grafted cotton

In this article, polyaniline (PANI)/cotton composite were prepared by in situ polymerization on the grafted cotton. First, acrylamide was grafted onto cotton cellulose using a radical graft polymerization process and some influencing factors were studied. Then polyaniline/cotton conductive composite fabrics were prepared by chemical in situ polymerization on the grafted cotton. The influences of the concentration of ammonium persulfate, aniline, hydrochloric acid, and the reaction time to the conductivity and K/S of composite fabric were studied. By contrasting, graft brought on an improvement of about one order of magnitude to the conductivity of composite fabric. The strength, TG, FTIR‐ATR, and SEM of prepared fabric were measured. The thermal stability and tear strength of composite fabric reduced, whereas PANI exhibited a rough but uniform, coherent PANI coating on surface of cotton fiber. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Improved surface characteristics and the conductivity of polyaniline–nylon 6 fabrics by plasma treatment

The effect of plasma treatment on the surface characteristics and conductivity of polyaniline–nylon 6 composite fabrics was investigated. Plasma surface modifications with oxygen, ammonia, and argon were performed on the nylon 6 fabrics to improve the adhesion and rate of polymerization. The surface morphology of the fiber was observed with scanning electron microscopy, and functional groups introduced onto the surface of nylon 6 fibers by various plasma treatments were characterized by X‐ray photoelectron spectroscopy. With oxygen plasma treatment, the fiber surface was effectively etched; polar groups such as ? OH and ? OOH were introduced onto the surface of nylon 6 fiber, and they increased surface activity, promoted oxidation polymerization, and resulted in higher add‐on and electrical conductivity. However, the introduced amine and amide groups with ammonia treatment caused a reduction in conductivity. Argon did not significantly alter the surface characteristics of the nylon 6 fibers. In addition, to control fabric conductivity and cover as wide a range of conductivity as possible, we observed the effects of the monomer concentration and number of deposits on the fabric conductivity. The results showed that fabric conductivity increased as the monomer concentration increased up to 0.5M and then leveled off, and further increases were achieved with an increase in the number of multiple deposits. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 684–694, 2001     

Effects of alcoholic solvents on the conductivity of tosylate‐doped poly(3,4‐ethylenedioxythiophene) (PEDOT‐OTs)

The effects of alcoholic solvents on the charge transport properties of tosylate‐doped poly(3,4‐ethylenedioxythiophene) (PEDOT‐OTs) are investigated. The use of different alcoholic solvents in the oxidative chemical polymerization of 3,4‐ethylenedioxythiophene (EDOT) with iron(III)‐p‐tosylate led to a change in the electrical conductivity of PEDOT‐OTs. For example, PEDOT‐OTs prepared from methanol shows a conductivity of 20.1 S cm^?1 which is enhanced by a factor of 200 as compared to PEDOT‐OTs prepared from hexanol. The variation of charge transport properties on the use of different alcoholic solvents is consistent with the data recorded by UV‐visible and electrospin resonance (ESR) measurements. From XPS experiments, the PEDOT‐OTs samples prepared from different alcoholic solvents were found to have almost the same doping level, suggesting that the number of charge carriers is not responsible for the change in conductivity. Supported by XRD results, it was found that the use of alcoholic solvents with shorter chain length induces more efficient packing of PEDOT chains. It is proposed that the alcoholic solvents associated with the counter ion of PEDOT via hydrogen bonding give rise to a change in the molecular ordering of PEDOT chains during the polymerization step, hence enhancing or depressing the inter‐chain hopping rate of the resulting PEDOT‐OTs. Copyright © 2005 Society of Chemical Industry     

Preparation and characterization of exfoliated organic montmorillonite/poly(3,4‐ethyldioxythiophene) nanocomposites

Montmorillonite, organically modified by octadecylammine salt, has been adopted to successfully fabricate the exfoliated organic montmorillonite/poly(3,4‐ethyldioxythiophene) (OMMT/PEDOT) nanocomposites by in situ polymerization in aqueous media. Hydrochloric acid, 1,5‐naphthalenedisulfonic acid, and sodium benzenesulphonate have been employed to activate the polymerization of 3,4‐ethyldioxythiophene by offering active sites on the layers of montmorillonite. The resulting exfoliated nanocomposites have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, thermogravimetric analysis, and electrical conductivity measurement and showed controllable conductivity in the range of 10^?7 to 10^?2 S/cm and improved thermal stability compared with pure PEDOT. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of poly(trimethylene terephthalate‐co‐2‐methyl‐ethylene terephthalate) random copolyesters

Poly(trimethylene terephthalate‐co‐2‐methyl‐ ethylene terephthalate) random copolymers of various compositions were synthesized via traditional two‐step polycondensation by incorporating of 1,2‐propanediol. The molar composition of trimethylene terephthalate and 2‐methyl‐ethylene terephthalate units and chemical structure were confirmed by means of ¹H‐NMR and Fourier transform infrared. The thermal properties of the copolyesters were evaluated by DSC and TGA. As far as the thermal properties is concerned, the main effect of incorporation of 1,2‐propanediol was a lowering in the melting temperature, and an increment of glass transition temperature compared to homopolymer PTT. Due to the effect of the lateral methyl groups in the polymeric chain, the thermal stability is slightly decreased as the amount of the MET units is increased. Furthermore, the crystals of PTT/MET copolyesters were observed by hot‐stage optical polarizing microscopy at the indicated crystallization temperatures. As expected, the incorporation of MET units in the polymer chain of PTT was found to decrease the dimension of the crystals. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

抗静电PTT及其纤维的研制

采用精对苯二甲酸(PTA)、1,3-丙二醇(PDO)及抗静电剂直接酯化法合成具有抗静电性能的聚对苯二甲酸-1,3-丙二醇酯(PTT)。对合成的PTT切片固相增粘后进行高速纺丝制得165 dtex/36 f抗静电PTTDTY。结果表明:在聚合反应完成前20 min加入抗静电剂,抗静电剂质量分数控制在1.5%～2.5%,聚合得到的切片经过真空固相增粘至其特性粘数达0.950 dL/g,可得到可纺性好、抗静电性好的PTT。制得的PTTDTY纤维手感好,织物表面电阻率达到10~9～10~(10)Ω。     

PET/PTT合金结晶形态的研究

采用XP-201热台偏光显微镜研究了对苯二甲酸乙二醇酯（PET）/对苯二甲酸丙二醇酯（PTT）合金等温结晶时的结晶形态及影响因素。研究结果表明：随着等温结晶温度的升高,PET/PTT(40/60)合金的结晶诱导期变长;在观察的时间范围内各样品的球晶尺寸随着时间的延长而增大;随着PTT含量的增加,样品球晶的线生长速率增大,球晶尺寸增大;对比不同温度下等温结晶的球晶形态,PET/PTT(100/0)样品在190℃结晶时球晶尺寸最大, PET/PTT(40/60)样品和PET/PTT(100/0)样品在180℃结晶时球晶尺寸最大; PET/PTT(0/100)样品等温结晶时呈现出了复杂的条带球晶。     

原位聚合法制备聚对苯二甲酸丙二醇酯／蒙脱土复合材料及其表征

采用原位聚合法制备了聚对苯二甲酸丙二醇酯(PTT)像脱土(MMT)复合材料。X射线衍射和透射电子显微镜扫描结果表明所得复合材料为剥离型或部分剥离型结构。与纯PTT、相比，由于MMT、在PTT基体中达到纳米尺寸分散，PTT／MMT复合材料的热稳定性能、结晶性能和拉伸性能都得到了明显提高。     

PTT/蒙脱土复合材料非等温结晶行为的研究

采用差示扫描量热仪对熔融共混制备的聚对苯二甲酸丙二醇酯(PTT)/蒙脱土(MMT)复合材料非等温结晶行为进行了测试分析。研究结果表明:在相同的降温速率时,随着MMT含量的增加,PTT/MMT复合材料的结晶峰温向高温方向移动,结晶峰变窄,半结晶期也缩短;随着降温速率的增大,PTT/MMT复合材料的结晶峰温向低温方向移动,半结晶期变短。采用Ozawa法处理了PTT/MMT复合材料的非等温结晶过程,结果表明:MMT的加入改变了PTT的成核机理,加快了PTT的结晶速率。     

Polymer blends of poly(trimethylene terephthalate) and polystyrene compatibilized by styrene‐glycidyl methacrylate copolymers

The compatibilizing effects of styrene‐glycidyl methacrylate (SG) copolymers with various glycidyl methyacrylate (GMA) contents on immiscible blends of poly(trimethylene terephthalate) (PTT) and polystyrene (PS) were investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and ¹³C‐solid‐state nuclear magnetic resonance (NMR) spectroscopy. The epoxy functional groups in the SG copolymer were able to react with the PTT end groups (? COOH or ? OH) to form SG‐g‐PTT copolymers during melt processing. These in situ–formed graft copolymers tended to reside along the interface to reduce the interfacial tension and to increase the interfacial adhesion. The compatibilized PTT/PS blend possessed a smaller phase domain, higher viscosity, and better tensile properties than did the corresponding uncompatibilized blend. For all compositions, about 5% GMA in SG copolymer was found to be the optimum content to produce the best compatibilization of the blend. This study demonstrated that SG copolymers can be used efficiently in compatibilizing polymer blends of PTT and PS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2247–2252, 2003     

Preparation of polyaniline/nylon conducting fabric by layer‐by‐layer assembly method

In this article, layer‐by‐layer assembly technology was used to prepare polyaniline (PANI)/nylon conducting fabrics. PANI/nylon conductive composite fabrics were prepared by deposition of polyanion (PSS) and polycation (aniline cation) alternately. The pretreatment with PSS was discussed. The influence of the reaction time, aniline concentration, acid concentration and assembly time on the conductivity, and K/S values of composite fabric was studied. The optical reaction condition of assembly should be: the concentration of PSS was 20 g/L, the PSS‐treated nylon immersion in blended bath for 24 min, ammonium persulfate 0.1 mol/L, aniline 0.1 mol/L, p‐toluene sulfonic acid 0.3 mol/L. In the end, the conductive composite fabrics were characterized by fourier transformed Infrared‐attenuated total reflection spectroscopy and compared with pure nylon fabrics. At the same time, scanning electron microscopy, atomic force microscope (AFM), thermogravimetric analysis (TG), and mechanical properties were studied. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Lamellar morphology of poly(trimethylene terephthalate)/poly(ether imide) blends studied via small‐angle X‐ray scattering

The lamellar morphology of a melt‐miscible blend consisting of poly(trimethylene terephthalate) (PTT) and poly(ether imide) (PEI) prepared by solution precipitation has been investigated by means of optical polarized microscopy (POM) and small angle X‐ray scattering (SAXS). From the observation under POM, it was suggested that PEI was predominantly segregated into the interlamellar and/or interfibrillar regions upon PTT crystallization since the PTT spherulitic morphologies of blends were volume‐filling. From results of SAXS data analysis, a larger amorphous layer thickness was identified in the blends, showing that some PEI was incorporated inside the interlamellar regions after crystallization. Despite the swelling of the amorphous layer, the amorphous layer thickness was relatively independent of the blend composition. It was concluded that amorphous PEI was located in the interlamellar regions of PTT as the weight fraction of PEI (w_PEI) [≤] 0.1, while amorphous PEI was predominantly segregated into the interfibrillar regions of PTT as w_PEI > 0.1, and the extent of interfibrillar segregation increased with increasing w_PEI. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006