氯乙烯—甲基丙烯酸环氧丙酯共聚树脂的合成及其性能

采用甲基丙烯酸环氧丙酯（EAMA）与氯乙烯（VC）共聚以改进聚氯乙烯的加工性能。研究表明，少量EAMA与VC共聚，使聚合速率大为降低；共聚树脂的分子量随转化率增加而增大，随共聚组成中EAMA含量增加而逐渐减小；共取和树脂的热稳定性和加工性能随EAMA含量增加而提高。     

Synthesis and Their Thermal and Thermo-Oxidative Properties of Poly(benzimidazole amide imide) Copolymers

In this study, the 3′-dinitrobenzidine was first reacted with excess isophthaloyl chloride form a monomer with dicarboxylic acid end group. Two types of aromatic dianhydride (viz. pyromellitic dianhydride (PMDA) and 3,3′,4,4′-sulfonyldiphthalic anhydride (DSDA)), were also reacted with excess 4,4′-diphenyl-methane diisocyanate to form polyimide prepolymers terminated with an isocyanate group. The prepolymers was further extended with the diacid monomer to form a nitro group containing aromatic poly(amide-imide) copolymers. The nitro groups in these copolymers were hydrogenated to form amine groups and cyclized at 180 ^○C, to form the poly(benzimidazole amide imide) copolymers in polyphosphoric acid which acted as a cyclization agent. The resulting copolymers can be soluble in sulfuric acid and polyphosphoric acid, in sulfolane under heating to 100 ^○C, and in polar solvent N-methyl-2-pyrrolidone under heating to 100 ^○C with 5% lithium chloride. From the DSC and TGA measurements, it demonstrated that the glass transition temperature of copolymers exhibits a range of 270∼322 ^○C. The 10% weight loss temperatures exhibits a range of 460∼541 ^○C in nitrogen, and 441∼529 ^○C in air, respectively. The activation energy and the integration parameter of degradation temperature of the copolymers were evaluated by the Doyle–Ozawa method. It indicated that these copolymers exhibited good thermal and thermo-oxidative stability with the increase of imide content.     

Poly(methylphenylphosphazene)–Graft–Poly(methyl Methacrylate) Copolymers Via Atom Transfer Radical Polymerization

Atom transfer radical polymerization (ATRP) was used to graft poly(methyl methacrylate), PMMA, onto poly(methylphenylphosphazene), [(Me)(Ph)PN] _n , PMPP. A two-step process was used to convert a portion of the methyl substituents on [(Me)(Ph)PN] _n to –CH₂C(CH₃)₂OH groups and then to bromoalkyl groups, –CH₂C(CH₃)₂OC(=O)C(CH₃)₂Br, the latter of which served as initiation sites for ATRP of methyl methacrylate (MMA) in the presence of CuCl/bipyridine. Variations in the length of the grafted chains were investigated and the graft copolymers were compared to the parent polymer and blends of similar composition. The new bromoalkyl derivatives of [(Me)(Ph)PN] _n and the PMPP–graft–PMMA copolymers were characterized by elemental analysis, ¹H and ³¹P NMR spectroscopy, size exclusion chromatography (SEC), and differential scanning calorimetry (DSC). We dedicate this paper to Professor Harry R. Allcock for consistently maintaining the highest standards in his creative, pioneering work in inorganic rings and polymers.     

Polyester-Polyether Block Copolymers II. Thermal and Mechanical Properties of Poly(hexamethylene terephthalate)/Poly(oxytetramethylene) Block Copolymers

The melting and crystallisation behaviour of crystalline phases in poly (hexamethylene terephthalate)/poly(oxytetramethylene) block copolymers have been investigated in relation to copolymer composition and polyether block molecular weight (m.w.). In contrast to that in corresponding homopolymer blends, the polyester crystallinity in the block polymers is greatly reduced by incorporation of polyether units, though some persists even at low polyester contents. Concomitant changes in the glass transition temperatures show part of the polyester component to form a homogeneous component of the amorphous phase. The mechanical properties change with composition in parallel with the changes in copolymer crystallinity and T_g. Copolymers with 20-60 w % of poly(oxytetramethylene) units of m.w. 2000 are highly extensible elastomers. Those with higher m. w. polyether blocks have higher modulus and strength but suffer a serious loss of properties at 60d?C. The observations are interpreted in terms of a model in which polyester crystallites (and polyether crystallites also, for the higher m. w. polyether blocks) are supported within an amorphous matrix by tie-molecules whose nature changes with the copolymer compositions. The results are compared with those for analogous polyester-polyethers having different structural components.     

Synthesis and Properties of Poly(l-lactide)-b-poly (l-phenylalanine) Hybrid Copolymers

Hybrid materials constituted by peptides and synthetic polymers have nowadays a great interest since they can combine the properties and functions of each constitutive block, being also possible to modify the final characteristics by using different topologies. Poly(l-lactide-b-l-phenylalanine) copolymers with various block lengths were synthesized by sequential ring-opening polymerization of l-lactide and the N-carboxyanhydride of l-phenylalanine. The resulting block copolymers were characterized by NMR spectrometry, IR spectroscopy, gel permeation chromatography, MALDI-TOF and UV-vis, revealing the successful incorporation of the polyphenylalanine (PPhe) peptide into the previously formed poly(l-lactide) (PLLA) polymer chain. X-ray diffraction and DSC data also suggested that the copolymers were phase-separated in domains containing either crystalline PLLA or PPhe phases. A peculiar thermal behavior was also found by thermogravimetric analysis when polyphenylalanine blocks were incorporated into polylactide.     

Relaxation Behaviour of Poly(2-Hydroxyethyl Acrylate) and of Its Copolymers with 2-Hydroxyethyl Methacrylate

Abstract

The molecular mobility of poly(2-hydroxyethyl acrylate) (PHEA) and of its copolymers with 2-hydroxyethyl methacrylate (H EM A) was determined by means of dynamic mechanical measurements with a torsional pendulum. The low-temperature dispersion assigned to the motion of the hydroxyethyl groups of the side chains was observed at -133°C (1 Hz) for all polymers; its intensity increased with the content of HEMA. Another secondary dispersion of PHEA detected at -95°C(1 Hz) was ascribed to the motion of the side chains including oxycarbonyl groups. With the incorporation of HEMA the temperature of the latter dispersion remained virtually unchanged, but its intensity rapidly decreased. The main transition temperature of PHEA, T_a = 9°C (1 Hz) is lower than T_a of PHEMA by approximately 94°C; the effect of the copolymer composition on T_a could be described by means of a one-parameter equation. The sorption of water led to a significant decrease in the T_a of PHEA and to an intensification of the secondary relaxation process.     

Flow Properties of Ultrahigh-Molecular-Weight Poly(Methyl Methacrylate) in Semidilute Solutions

The article presents some Theological results obtained on a large domain of shear rates for semidilute solutions of ultrahigh-molecular-weight poly(methyl methacrylate) at different concentrations. The observed unusual behavior was explained as being due to the flow instabilities of long-chain polymers in an entangled state.     

Role of Different Plasticizers in Li-Ion Conducting Poly(Acrylonitrile)-Poly(Methyl Methacrylate) Hybrid Polymer Electrolyte

In this work, polymer electrolytes composed of PAN/PMMA/LiClO₄ with different plasticizers are prepared using solvent casting technique. Ionic conductivity of the electrolytes is evaluated with the help of ac impedance study at various temperatures. Structural and the complexation of the prepared electrolytes are studied by XRD and FTIR analysis, respectively. Thermogravimetric/differential thermal analysis (TG/DTA) is used to find the thermal stability of the polymer electrolytes. PAN/PMMA/EC/LiClO₄-based plasticized polymer electrolyte is found to possess optimal properties in terms of conductivity and thermal stability. Porous nature of the polymer gel electrolytes is also confirmed by SEM analysis.     

Effect of Chromium Compounds on Thermochemical Transformations of Graft Copolymers of Polycaproamide and Poly(Dimethylaminoethyl Methacrylate)

IR spectroscopy and differential thermal and thermogravimetric analysis showed that impregnation of PCA fibre modified by grafting poly(dimethylaminoethyl methacrylate) (PDMAEMA) and chromium-containing compounds causes loss of thermoplasticity, accumulation of double bonds, a decrease in the maximum rate of decomposition, and an increase in coke residue. It was found that the yield of the final product increases in fabrication of carbon fibre from graft PCA—PDMAEMA copolymers in the presence of Cr(NO₃)₃ + (NH₄)₂HPO₄. The carbon fibre containing chromium salts has a more developed pore structure than the initial fibre, as the almost ten-fold increase in the value of sorption of I₂ indicates.     

Properties of Block Copolymers of Poly(Butylene Terephthalate) and Polyoxytetramethylene Glycol

Synthesis of polyester thermoelastoplasts, block copolymers of polyoxytetramethylene glycol and poly(butylene terephthalate) of the polyblock type, was developed and implemented in pilot industrial conditions. POTM blocks act as flexible molecular decouplings that give the copolymer elasticity, while PBT blocks form physical linkages and are responsible for the mechanical strength and hardness of the material. The composition of the reaction systems, process stage sequence, and synthesis parameters are optimized for block copolymers with a concentration of the flexible POTM block of 65-10 wt. % and a molecular weight of 1000. The structure is investigated, and the physicochemical and mechanical properties of the material obtained are determined. It was found that the concentration of flexible blocks has a determining effect on the physicochemical structure and properties of the block copolymers. For a 40% concentration of the flexible block, the character of the concentration curves of the physicomechanical indexes changes significantly due to phase-structural transformations in the block copolymers.     

Synthesis,Characterization, and Conducting Properties of Poly(thiourea azomethines)

Three new polyazomethines having phenylthiourea groups were synthesized through solution polycondensation of terephthalaldehyde with 4,4′-bis(thiourea)biphenyl ether, 4,4′-bis(thiourea)biphenylmethane, and 4,4′-bis(thiourea)biphenyl sulphone. For comparison purposes, simple polyazomethines were prepared by the polycondensation of terephthalaldehyde with 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl sulphone. Poly(imine)s having phenylthiourea groups were characterized through IR and ¹H-NMR spectroscopic methods and the thermal stability of the polymers were evaluated through TGA analysis. Conductivity of polyaniline synthesized in aqueous p-toluenesulfonic acid was found to be 3.83 Scm^?1. The conductivity of the polymeric blends with polyaniline dopped with p-toluenesulfonic acid and HCl (20% by weight) were found to be in the range 0.16 × 10^?3 ? 5.7 × 10^?3 Scm^?1.     

纳微米聚（3，4-二氧乙基噻吩）导电高分子的合成及其性能研究

在导电高分子家族中，聚（3，4-二氧乙基噻吩）（PEDOT）由于具有高的电导率、环境稳定性、透明性以及良好的成膜性等优异性能而广泛地应用于有机电致发光器件、太阳能电池、防静电、电致变色器件、传感器等领域．本论文研究了绝缘高分子聚乙二醇（PEG）和乙二醇、一缩二乙二醇等有机极性溶剂提高PEDOT／PSS（聚苯乙烯磺酸钠）电导率的机理，并通过改变稳定剂、掺杂剂等因素制备了具有不同结构和性能的PEDOT胶体颗粒以及PEDOT／PMMA（聚甲基丙烯酸酯）复合微球，取得了以下主要的创新性结果。     

聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子的制备及性能

由种子乳液聚合法制备了聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子。以过硫酸钾（KPS）为引发剂，分别以非离子型辛基酚聚氧乙烯醚（OP—10）和复合十二烷基硫酸钠（SDS）／OP—10（质量比为1：4）为乳化剂，合成了聚苯乙烯种子核。连续滴加甲基丙烯酸甲酯（MMA），以OP—10乳化的种子乳液可以制备粒径范围在0．16～0．67μm的核-壳粒子，当单体苯乙烯与甲基丙烯酸甲酯（St／MMA）的质量比为3：7时，所得粒径为0．18μm，粒径分散系数为0．012。而以OP-10／SDS质量比为4：1制备的种子乳液所得核壳粒子直径在毫米级。差示扫描量热研究显示，以OP-10乳化所得种子乳液制衢的复合粒子的玻璃化转变温度为97．2℃，峰形单一，表现山良好的热性能。     

Comparison of Poly(Ethylene Oxide) Melt Crystallization in Blend and Block Copolymer Systems with Poly (Methyl Methacrylate) and Poly (Tert-Butyl Methacrylate)

DSC investigations are reported for a broad assortment of blends and copolymers of the immiscible poly(ethylene oxide) (PEO)/poly(tert-butyl) methacrylate) (PTBMA) system. Contrary to expectations, the PEO crystallization and melting behavior of the copolymer system is similar to that of the PEO/poly(methyl methacrylate) (PMMA) copolymer system (which is usually considered to be miscible in the melt). This is discussed with the concept of a UCST-type granulated demixing in the latter. In both systems the crystallization is rather sensitive to the block structure, even for comparable molecular weights and compositions. This indicates some importance of DSC as an additional tool in copolymer characterization. Free PEO ends favor the crystallization in all cases.     

Electroactive Nanofibers of Poly (2-hydroxyethyl methacrylate-graft-aniline) Copolymers and Their Blends with Polycaprolactone

Copolymers of poly (2-hydroxyethyl methacrylate)-graft-polyaniline (PHEMA-g-PANI) were synthesized by atom-transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate using polyaniline macro-initiators. The macro-initiators were synthesized by the reaction of amine nitrogens of polyaniline with chloroacetyl choloride. The obtained polymers were characterized by FT-IR and ¹H NMR spectroscopies. Uniform nanofibers consisting of blends of PHEMA-g-PANI copolymers and polycaprolactone (PCL) were prepared using an electrospinning technique. SEM was used to investigate the morphology of nanofibers produced from PHEMA-g-PANI copolymers and PCL blends. The cyclic voltammetry measurement of blends confirmed the preparation of electroactive nanofibers.     

Electrical and Optical Properties of Conducting Poly(3-hexylthiophene)/Multi-walled Carbon Nanotube System

Polymer multi-wall carbon nanotube (MWNT) composites were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use in solar cell applications. Multi-walled carbon nanotube (MWNT) poly(3-hexylthiophene) nanocomposites were synthesized by in situ polymerization of monomers in the presence of different amounts of MWNTs. A process is reported to efficiently disperse multi-walled carbon nanotube (MWNT) bundles in a semiconducting polymer matrix. A uniform dispersion of the nanotubes in the polymer matrix was obtained. Characterization of the nanocomposites and the effects of MWNT concentration and dispersion on the structural, optical and electrical properties were discussed. FTIR and Raman spectroscopic investigations of nanocomposites indicate that the polymer is wrapped on the nanotubes, taking up a rigid orientation through π-π stacking. The Hall voltage measurement is followed to monitor carrier concentrations and mobilities, instead of the device fabrication and hole mobility measurements.     

基于聚3-己基噻吩的嵌段共聚物研究进展

随着全球对新能源、新材料研究领域的战略提升,聚3-己基噻吩(P3HT)作为导电共轭聚合物的相关研究已成为近年来的一个热点,并取得了突飞猛进的进展。P3HT均聚物受其激发子寿命短的影响,其光电转换效率有限,而嵌段共聚物可以实现微相分离,进而可以实现提高有机光伏材料的光电转换效率的目的。总结了近年研究者们合成的嵌段共聚物及其合成方法。     

Synthesis of Triblock Copolymers via Photopolymerization of Styrene and Methyl Methacrylate Using Macrophotoinitiators Possessing Poly(ethylene glycol) Units

Macrophotoinitiators based on poly(ethylene glycol)s bearing benzyl tereftalmono amid moieties were synthesized by the reaction of poly(ethylene glycol) (PEG) terminated with terephtaloyl chloride and benzyl amine. The initiators possessing PEG with different molecular weights were used in the photoinduced radical polymerization of styrene (S) and methyl methacrylate (MMA) to yield poly(styrene-b-ethylene glycol-b-styrene) and poly(methyl methacrylate-ethylene glycol-b-methyl methacrylate) triblock copolymers. Characterization of macrophotoinitiators were performed by elemental anlysis, IR and ¹H-NMR spectrum. The elemental analysis results agreed with the theoretical values. The IR and ¹H-NMR spectra showed that the poly(ethylene glycol) units were reacting with the tereftloyl chloride and benzylamine. Characterization of the block copolymers was carried out by spectral measurements, GPC and fractional precipitation methods. The polydispersities of the block copolymers were observed between 1.2–2.32 for poly(methyl methacrylate-ethylene glycol-b-methyl methacrylate) and 1.25–1.90 for poly(styrene-b-ethylene glycol-b-styrene) from GPC measurements.     

Macroazoinitiators Based on Poly(Methyl Methacrylate)

A series of bi- and trifunctional initiators were tested in the initiation of methyl methacrylate (MMA) polymerization by dilatom-etry; in the first stage, “active” prepolymers with azo and peroxy groups were obtained. In an effort to elucidate some aspects of the decomposition mechanism, an “active” PMMA synthesized with phenylazoformamidoethyl 4-t-butylazo-4-cyanopentanoate was investigated by pyrolitic mass spectroscopy. Finally, these macroazoinitiators were applied in the synthesis of some block copolymers with isoprene.     

单分散聚甲基丙烯酸甲酯微球的制备

选择分散聚合方法制备微米级单分散聚甲基丙烯酸甲酯微球,改变反应物间的配比及反应条件,考察了引发剂浓度、稳定剂浓度对微球粒径的影响及变化规律,同时对微米级单分散聚甲基丙烯酸甲酯微球提出最佳的制备方案.