Synthesis,spectroscopy, and electrochemical investigation of new conjugated polymers containing thiophene and 1,3,4-thiadiazole in the main chain

Novel photoluminescent donor–acceptor poly(p-phenylenevinylene)-type conjugated polymers containing thiophene and 1,3,4-thiadiazole units in the main chain were synthesized from 2,5-bis(5-bromomethyl-2-thienyl)-1,3,4-thiadiazole and 1,3/1,4-benzenedialdehyde by Wittig–Horner reaction. The synthesized polymers were characterized by the use of thermal analysis and spectroscopic (infrared, UV-visible absorption, and photoluminescence) measurement. The resultant material exhibited bluish green, green, and orange fluorescence in their solution and thin film and solid forms, respectively. The redox property of the polymers has also been studied by cyclic voltammetry. The optical and electrochemical studies reveal that these novel polymers are new promising materials for the development of efficient polymer light-emitting diodes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Tailoring of energetic groups in acroyloyl polymers

Acryloyl based novel energetic monomers having nitro acrylates and nitro triazole acrylates were synthesized and further used for polymerization. Due to scavanging properties of nitro groups, syntheses of nitro aromatic polymers are not facile at normal conditions. In this regard, we report a simple protocol to synthesize these energetic group embeded acroloyl polymers. These polymers were characterized by FTIR, and NMR spectroscopic techniques. gel permeation chromatography (GPC) technique was employed in order to understand molecular mass of these polymers along with average molecular weight, number average weight and poly dispersity index. Glass transition temperature (T_g) was determined by using DSC analysis. It was observed that with increase in nitro groups in polymers there is a decrease in glass transition temperature. Two steps degradation were depicted in the TGA thermograph in nitro containing polymers. Heat release during this reaction was found up to 951 J/g. Increase in nitrogen content in polymer unit enhanced the heat release of polymers.     

Synthesis and characterization of N‐ and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]

Poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] was synthesized in an aqueous hydrochloric acid medium with a determined feed ratio by chemical oxidative polymerization. This polymer was used as a functional conducting polymer intermediate because of its side‐group reactivity. To synthesize the alkyl‐substituted copolymer, the initial copolymer was reacted with NaH to obtain the N‐ and O‐anionic copolymer after the reaction with octadecyl bromide to prepare the octadecyl‐substituted polymer. The microstructure of the obtained polymers was characterized by Fourier transform infrared spectroscopy, ¹H‐NMR, and X‐ray diffraction. The thermal behavior of the polymers was investigated by thermogravimetric analysis and differential scanning calorimetry. The morphology of obtained copolymers was studied by scanning electron microscopy. The cyclic voltammetry investigation showed the electroactivity of poly [aniline‐co‐N‐(2‐hydroxyethyl) aniline] and N and O‐alkylated poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline]. The conductivities of the polymers were 5 × 10^?5 S/cm for poly[aniline‐co‐N‐(2‐hydroxyethyl) aniline] and 5 ×10^?7 S/cm for the octadecyl‐substituted copolymer. The conductivity measurements were performed with a four‐point probe method. The solubility of the initial copolymer in common organic solvents such as N‐methyl‐2‐pyrrolidone and dimethylformamide was greater than polyaniline. The alkylated copolymer was mainly soluble in nonpolar solvents such as n‐hexane and cyclohexane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Modelling of a continuous kneader reactor for the polymerization of partially neutralized acrylic acid

A mathematical model and analysis of the continuous polymerization of partially neutralized acrylic acid (AA) in a continuous kneader reactor is presented here as an initial attempt to simulate the synthesis of a superabsorbent polymer. A detailed kinetic model has been used to describe the copolymerization of AA and sodium acrylate (NaA) in aqueous medium. This model is used to describe batch and continuous operations. The polymerization is initiated by a mixture of potassium persulphate (K₂S₂O₈, KPS) and hydrogen peroxide (H₂O₂) as oxidizing agent and ascorbic acid (AsA) as reducing agent. A novel set of kinetic parameters has been estimated by fitting experimental data from different literature sources. The operation of a continuous kneader reactor modelled as a plug-flow reactor with axial dispersion is theoretically investigated to predict temperature profile, total and individual monomer conversion, consumption of KPS, H₂O₂, and AsA, and polymer average molecular weights. The simulation results show the presence of a hot spot close to the reactor entrance that could be potentially severe during startup and could have a detrimental impact on polymer quality. This model is a first step in the direction of achieving optimal operating protocols and exploring improved polymerization reactor designs.     

Fabrication of photochromic hydrogels using an interpenetrating chitosan network

The synthesis of a novel interpenetrating chitosan network post‐modified with spiropyran (SP) derivatives has been used to develop photochromic hydrogels. We have synthesized succinyl chitosan polymers containing a considerable number of both amines and carboxylic groups. Their intra/inter molecular amide coupling reactions and postmodification with SP derivatives resulted in the photochromic hydrogels functionalized with chitosan‐based interpenetrating polymer network structures. In this hydrogel system, SPs undergo reversible photoresponsive structural switching between a ring‐closed colorless SP form and a ring‐opened purple merocyanine form under specific light‐irradiation conditions. Notably, the photo‐mediated wettabilities and color intensities of the hydrogels increase by the increment in the molecular weight of SP‐functionalized chitosans. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45120.     

端叠氮基聚叠氮缩水甘油醚的合成与热性能

以不同多元醇为起始剂,环氧氯丙烷经阳离子开环聚合得到不同结构的端羟基聚环氧氯丙烷(PECH-OH),将其端羟基进行磺酰化改性得到端磺酸酯基聚环氧氯丙烷(PECH-OTS),随后的叠氮化反应中叠氮基同时取代PECH-OTS的端磺酸酯基和侧基中的氯得到目标产物。用IR、GPC、TG和DSC对不同结构的GAPA进行了表征。结果表明,GAPA-2、GAPA-3和GAPA-4的数均相对分子质量分别为810、830和1190,玻璃化转变温度分别为-67.5、-63.8和-58.6℃,端叠氮基聚叠氮缩水甘油醚(GAPA)的热分解可分为相对独立的叠氮基热分解(250℃)和聚醚主链热分解。     

New soluble cyano‐containing poly(arylene ether) copolymers bearing pendant xanthene groups

Homopolymers and copolymers of poly(arylene ether nitrile) (PAEN)‐bearing pendant xanthene groups were prepared by the nucleophilic substitution reaction of 2,6‐difluorobenzonitrile with 9,9‐bis(4‐hydroxyphenyl)xanthene (BHPX) and with various molar proportions of BHPX to hydroquinone (100/0 to 40/60) with N‐methyl‐2‐pyrrolidone (NMP) as a solvent in the presence of anhydrous potassium carbonate. These polymers had inherent viscosities between 0.61 and 1.08 dL/g, and their weight‐average molecular weights and number‐average molecular weights were in the ranges 34,200–40,800 and 17,800–20,200, respectively. All of the PAENs were amorphous and were soluble in dipolar aprotic solvents, including NMP, N,N‐dimethylformamide, and N,N‐dimethylacetamide and even in tetrahydrofuran and chloroform at room temperature. The resulting polymers showed glass‐transition temperatures (T_g's) between 220 and 257°C, and the T_g values of the copolymers were found to increase with increasing BHPX unit content in the polymer. Thermogravimetric studies showed that all of the polymers were stable up to 422°C with 10% weight loss temperatures ranging from 467 to 483°C and char yields of 54–64% at 700°C in nitrogen. All of the new PAENs could be cast into transparent, strong, and flexible films with tensile strengths of 106–123 MPa, elongations at break of 13–17%, and tensile moduli of 3.2–3.7 GPa. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Catalytic activity of a reusable polymer‐anchored nickel(II)–phenanthroline complex on the oxidation of various organic substrates

A polymer‐anchored nickel(II)–phenanthroline complex [polyNi(II)–phen] was synthesized and used effectively as a reusable catalyst in various oxidation reactions in the presence of tert‐butylhydroperoxide as an oxidant in acetonitrile medium. The catalyst was characterized with elemental analysis, atomic absorption spectrometry (AAS), thermogravimetric analysis, scanning electron microscopy, and spectrometric methods such as diffuse reflectance spectroscopy, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy. The study of the effects of the time, temperature, oxidant, catalyst concentration, molar ratio of substrate to oxidant, and solvent in the oxidation of styrene individually gave the optimized reaction conditions. Under optimized conditions, the catalyst exhibited good conversions for the oxidation reactions of various olefins, alkanes, aromatic alcohols, and thioethers. The catalyst was easily recovered by simple filtration and reused for more than five times with consistent catalytic activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

《高分子化学与物理》课程教学初探

针对《高分子化学与物理》课程内容众多、学时有限等特点,探讨了如何提高教学质量,激发学生的学习兴趣,培养学生的创新意识等问题,提出合理安排教学内容、多媒体和和板书相结合、突出教学重点、以科研促教学、加大课堂互动力度等具体措施,以期取得良好的教学效果。     

Synthesis,exchange reactions,and biological activity of poly(8‐methacryloxyquinoline)

8‐Methacryloxyquinoline (MAQ) was prepared through the reaction of 8‐hydroxyquinoline with either methacryloyl chloride or methacrylic acid in the presence of triethylamine or N,N‐dicyclohexylcarbodiimide, respectively. MAQ was polymerized in dimethylformamide with 2,2‐azobisisobutyronitrile as the initiator. The reactions of the resulting polymers with hydroxyl and amino compounds were studied. The polymers were characterized with IR, ¹H‐NMR, and mass spectroscopy. Some of the synthesized polymers were tested for their antimicrobial activity against bacteria and fungi. Generally, all the polymers were effective against the tested microorganisms, but their growth‐inhibition effects varied. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

高分子化学与物理实验网络教学平台的构建与实践研究

网络与智能手机技术的发展为传统实验教学带来了机遇与挑战。通过整合多种教育技术,我们构建了一个全新的高分子化学与物理实验网络教学平台。教学评价结果显示网络教学促进了学生的学习兴趣,获得了正面效果。     

Synthesis and Reactions of Organometallic Polymers Containing Titanacyclobutene Units in the Main Chain

A new class of polymers containing titanacyclobutene units in the main chain were prepared by the reaction of organic dihalides (2) with a binuclear titanium propargyl complex (3) generated in situ from bis(pentamethylcyclopentadienyl)titanium chloride (Cp*₂TiCl, 1), SmI₂, and 1,4-bis(3-bromopropynyl)benzene (2a). The dark red colored polymers (4) thus obtained are soluble in organic solvents such as tetrahydrofuran and chloroform, and they are stable at ambient temperature under argon atmosphere. The reaction of the titanium-containing polymers (4) with hydrogen chloride was found to give organic polymers (7) containing unsaturated main chain.     

《高分子化学实验》教学内容的选取与整合优化

针对应用化学专业,在同期专业课程门类较多、学生学科基础相对薄弱、学时数有限的条件下,从单体和引发剂的精制、聚合实施方法、聚合物的化学反应三个方面对高分子化学实验内容进行选取与整合优化;以验证性实验为基础,引入设计性实验并紧密联系实际开设应用性实验,各类型实验互相渗透、相互关联,形成有机整体;增强了实验的趣味性和实用性,有助于相关理论知识的深化,提高了学生的综合实验水平。     

《高分子化学》双语教学的探索与实践

双语教学是当前高等院校教育教学改革的一个热点问题。为此,本文在分析专业基础课双语教学的特点与难点的基础上,对双语教学中的教学计划安排、教学内容取舍、原版教材选用以及教学方式与方法等问题进行了深入的探讨,提出了一些个人见解。     

Synthesis and characterization of novel organosilicon-modified polyurethane

Organosilicon-modified polyurethane have been synthesized using the prepolymer method and characterized by Fourier infrared (FTIR) spectroscopy, wide angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), solvent resistance analysis, and stress–strain tests. The FTIR spectra show that the polyurethane is fully reacted and polydimethylsiloxane (PDMS) is chemically incorporated into the copolymer. SEM reveals a multiphase structure with surface cracking and thermal analysis indicates that the heat resistance properties are better when the PDMS concentration is low. According to the solvent resistance, water and acetone uptake decreases when the PDMS content is less than 4 wt % while the ethanol uptake changes indistinctively. The mechanical properties of the films are also discussed. A tensile strength up to 6 wt % has the largest effect while the elongation at break decreases. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci 125:1486–1492, 2012     

Double dynamic self‐healing polymers: supramolecular and covalent dynamic polymers based on the bis‐iminocarbohydrazide motif

Self‐healing polymers are a class of functional polymers that, by the virtue of the presence of certain dynamic chemical linkages, may undergo self‐repair at a mechanically cut surface. Herein we report the synthesis of a self‐healing polymer giving access to double dynamicity within the polymer network by making use simultaneously of reversible covalent bonds and dynamic non‐covalent hydrogen bonding interactions. These features are provided, respectively, by doubly dynamic cassettes comprising chemically reversible imine linkages and multiply hydrogen‐bonded urea groups, connected by a siloxane‐based backbone that imparts softness to the material. Such a system can be envisaged to give access to a broad spectrum of functional materials, which can be tuned by convenient modulation of the structural motifs of the polymer. © 2013 Society of Chemical Industry     

Preparation of antibacterial poly(methyl methacrylate) by solution blending with water-insoluble antibacterial agent poly[(tert-buty1amino) ethyl methacrylate]

A simple and effective way was developed to prepare antibacterial poly(methyl methacrylate) (PMMA) materials from commercial PMMA and synthesized poly[2-(tert-butylamino) ethyl methacrylate] (PTBAEMA) by solution blending and solvent evaporation methods. The chemical structure of as-synthesized PTBAEMA was characterized by FTIR and ¹H-NMR, and the molecular weight (M_w) and polydispersity index was determined by Gel Permeation Chromatograph. The two components, that is, PMMA and PTBAEMA, were partially miscible and of regular domain size and shape as revealed by SEM observation. Antibacterial assay revealed PMMA/PTBAEMA blends inherited the good antibacterial activity of PTBAEMA against both Staphylococcus aureus and Escherichia coli, no matter whether the bacteria were waterborne or airborne. Besides, the antibacterial performance of PMMA/PTBAEMA blends depended on the M_w and dosage of PTBAEMA, and type of bacteria strain. Furthermore, it was proved that PMMA/PTBAEMA blends killed bacteria on direct contact without releasing active component, which sufficiently met the demand of developing environment-friendly antibacterial materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012