反应条件对聚苯胺-邻氨基苯甲酸性能影响

以苯胺（An）和邻氨基苯甲酸（OAA）为单体，共聚制备了一种可溶性聚苯胺邻氨基苯甲酸（PAOAA），研究了反应条件对PAOAA电导率和溶解性的影响。结果表明，在水浴中An／OAA摩尔比为1．00、反应时间为18h时，制备了电导性和溶解性都较好的PAOAA。     

Effect of γ-Irradiation on the Electrical Properties of Poly (Methyl Methacrylate) Doped with Some Transition Metal Complexes

Abstract

The electrical resistivity (p) of pure and doped poly(methyl methacrylate), PMMA, with dithizone (HDZ) and its metal complexes, Zn(HDZ)₂, Cd(HDZ)₂ and Hg(HDZ)₂ has been investigated before and after γ-irradiation. The results show a phase transition at nearly 323°K. The activation energy of the conduction process has been calculated below and above the transition temperature. Further information concerning the electrical behaviour is obtained by considering the type and mechanism of the conduction process. This has been achieved by studying the effect of temperature and γ-irradiation on the mobility and the number of charge carriers which take part in the conduction process.     

Doped Poly(m-phenylenediamine-co-aniline) (P(mPD-co-ANI)): Synthesis,Characterization, Physical Properties,and Precursor for CuO Nanoparticles

Poly(m-phenylenediamine-co-aniline) P(mPD-co-ANI) and Mn-, Ni-, and Cu-doped poly(m-phenylenediamine-co-aniline) (M-P(mPD-co-ANI)) have been synthesized and characterized. Cu-P(mPD-co-ANI) has been used as a molecular precursor of CuO nanoparticles. The spectral, optical, refractive index, solubility, and thermal properties of the synthesized polymers have been measured and discussed. The optical bandgap (E_g) measurements indicated that Ni(P(mPD-co-ANI)) has wider optical band than the pure (P(mPD-co-ANI)). Calcination of Cu-P(mPD-co-ANI) at 600°C produced (CuO) nanoparticles. The obtained nanoparticles have been characterized by XRD and TEM. The average size of CuO nanoparticles was found to be 42?nm. The refractive index measurements indicate slight change in the refractive index values of the polymer solution than that of pure solvent. The solubility of the synthesized polymers in ethanol, dimethyl formamide (DMF)–aqueous mixed solvents was found to increase as the mole fractions of both ethanol and DMF increase. The UV spectra of the synthesized polymers in ethanol, DMF–aqueous mixed solvents indicate blueshift and hyperchromic effect.     

单宁酸/硫酸掺杂聚邻甲氧基苯胺的吸附性能

以邻甲氧基苯胺为单体,通过化学氧化聚合法合成了单宁酸/硫酸掺杂聚邻甲氧基苯胺(POMA-H-GA),采用FTIR、XRD、SEM及BET对其结构进行了表征。通过平衡吸附实验考察了POMA-H-GA对Cr~(3+)的吸附性能,并以其为指标优化了Cr~(3+)溶液初始质量浓度、时间、温度、pH。结果表明:POMA-H-GA在Cr~(3+)初始质量浓度为0.1 g/L、时间3 h、温度25℃、pH=3.0~4.5时,吸附量为18.2 mg/g,吸附率达到93.2%,POMA-H-GA对几种重金属离子的吸附量大小顺序为Cr~(3+)Hg~(2+)Pb~(2+)Cd~(2+)。     

Effect of Cobalt and Nickel Doping on Structural and Magnetic Properties of Iron Oxide Nanoparticles

Two series samples of Iron Oxide nanoparticles doped with nickel and cobalt with different doping values (x?=?0.01; 0.03; 0.05 and 0.07), were successfully synthesized by using sol–gel method, and then they were characterized by X-ray diffraction, scanning electron and vibrating sample magnetometer (VSM). X-ray diffraction analysis of two series samples showed the formation α-Fe₂O₃ nanoparticles, accompanied by two phases iron spinels, CoFe₂O₄ and NiFe₂O₄. In addition, the variations in grain size were observed for both two series. The observation by scanning electron microscopy reveals a change in the morphology of the grains of all the samples doped, which confirm the cobalt and nickel effect on the morphology of iron oxide nanoparticles. Magnetic measurements which were measured by VSM showed significant magnetic parameters such as coercivity and magnetization besides the ferromagnetic behavior of both two series doped with Cobalt and Nickel.

     

碱溶性聚(丙烯酸丁酯/丙烯酸)的合成及性能

合成了碱溶性聚(丙烯酸丁酯/丙烯酸)〔P(BA/AA)〕,探讨了丙烯酸用量及不同引发体系对其表面张力、离心稳定性和乳化性的影响,对其结构进行了表征。傅里叶红外光谱(FTIR)分析表明,P(BA/AA)中无C C存在,聚合完全;差示扫描量热(DSC)分析表明,共聚物的玻璃化转变温度(Tg)为21.3℃;透射电镜(TEM)测定了P(BA/AA)的平均粒径小于100 nm,粒径分布均匀。以该共聚物为表面活性剂与丙烯酸酯类进行乳液聚合制备了皮革涂饰剂,应用于皮革涂饰后,革样的物理机械性能较采用常规乳化剂制备的丙烯酸树脂涂饰革样抗水性提高了28.08%,透气性提高了18.5%,耐湿擦性提高了半级,耐折牢度无明显变化。     

掺杂MnO2对铁酸镍陶瓷惰性阳极性能的影响

为了提高铝电解惰性阳极材料的性能,尝试在合成铁酸镍陶瓷阳极的过程中掺杂一定量MnO2. 采用高温固相反应法在1200℃下烧结6 h,制备了掺杂MnO2的铁酸镍阳极材料. 对掺杂试样进行X射线衍射分析,并且研究了掺杂MnO2对材料密度、导电性及抗弯强度和抗热震性的影响. 研究结果表明,掺杂MnO2后未形成新相,MnO2与NiFe2O4形成固溶体,Mn4+离子取代了部分Fe3+离子,材料仍是镍铁尖晶石结构;掺杂MnO2后,NiFe2O4的晶格产生畸变,说明MnO2促进了烧结,提高了材料的密度;并且由于Mn4+离子取代Fe3+离子,产生阳离子空位,改善了铁酸镍阳极的导电性. 同时MnO2对改善试样的抗弯强度及抗热震性也有明显作用.     

Effect of Magnesium Ions on the Adsorption of Poly(acrylic acid) onto Alumina

The adsorption isotherms of poly(acrylic acid) (PAA) onto alumina powder have been determined as a function of pH, ionic strength, and magnesium-ion concentration. The adsorption of PAA is strongly enhanced by magnesium ions in alkaline media but less affected under acidic conditions. The adsorption isotherms display a maximum when PAA is fully complexed with magnesium ions in the solution, corresponding to a ratio of 0.25 ± 0.05 [Mg²⁺]/[acrylic acid monomer]. The decrease in adsorbed amount with an increase in PAA concentration at constant magnesium-ion concentration is related to a decrease in the complexation ratio.     

聚羟基丁酸己酸酯对聚乳酸结晶性能的影响

通过溶液共混法制备了生物可降解左旋聚乳酸(PLLA)和聚羟基丁酸己酸酯(PHBHHx)复合材料,用差示扫描量热仪和偏光显微镜研究了PHBHHx对PLLA热性能与结晶性能的影响。结果表明,PLLA与PHBHHx存在一定的相容性和相互作用,PLLA的玻璃化转变和冷结晶行为随着共混组成而变化。PLLA的相对分子质量越大,球晶形貌的规整性越差。当PHBHHx含量达到30%(质量分数,下同)时,其能加快PLLA的链段运动,提高结晶的成核密度,加快结晶速率。     

苯乙烯——甲基丙烯酸共聚物的合成及表征

采用简单、经济、稳定的悬浮聚合法合成了苯乙烯—甲基丙烯酸共聚物(SMAA),得率为92%左右.通过正交试验确定了最佳配方.经FT—IR、DSC、元素分析、化学滴定、GPC等测试方法表征,证实了所合成的产物为透明的苯乙烯—甲基丙烯酸无规共聚物.研究表明,SMAA的耐热性比PS好得多,其玻璃化温度随共聚物中MAA含量的增加而增大,SMAA20的Tg为138.8℃,比PS的约高40℃,在100℃时热拉伸强度保留率为72.3%.共聚物的加工性能良好,熔体指数为8.05g/10min(230℃,载荷50N),熔化特性良好.其力学性能比PS有明显提高,拉伸强度和弯曲强度分别比PS提高52.2%和43.6%.     

阻燃PTT共聚酯的制备及性能研究

采用直接酯化-缩聚工艺,在酯化后加入磷系阻燃剂2-羧乙基苯基次膦酸(CEPPA)与1,3-丙二醇(PDO)的酯化溶液(CEPPA-PDO),制得阻燃聚对苯二甲酸丙二醇共聚酯(FR-PTT)。通过FT-IR、DSC、TG、SEM以及垂直燃烧法对FR-PTT的结构及性能进行表征。结果表明:阻燃剂CEPPA可能是以共聚的方式接入到大分子链中,并且随着磷含量的增加,FR-PTT的Tc上升,而Tm呈下降趋势,同时FR-PTT在高温处理后成炭性良好,阻燃级别达到FV-0级。     

Sn掺杂对ZnO压敏变阻器电学性能的影响

本文采用沉淀法以SnCl2·H2O代替SbCl3制备了ZnO压敏变阻器.分析了SnO2含量对变阻器电学性能的影响.随着SnO2含量的增加,漏电流和压敏电压明显增大;而非线性系数在SnO2掺杂量达到3.0 mol％时达到极大值.通过适当的掺杂,得到了漏电流为0.08 μA,非线性系数为80.3,压敏电压为1006.7 V1mA/mm性能良好的ZnO变阻器.     

Morphological and Mechanical Properties of Poly (Vinyl Alcohol) Doped with Inorganic Fillers

A number of polymer composite films using polyvinyl alcohol (PVA) as the preorganized polymer matrix were synthesized embedding different metal salts of transition elements like copper, cobalt, nickel, iron, cadmium, and zinc by a biomimetic route. The metal salts present in composites were reduced in situ to metallic form. The composites were characterized by FTIR, SEM, and EDAX. The SEM analysis confirmed the presence of nano-sized metal particles uniformly distributed in the polymer matrix. Mechanical properties were measured for various composite and PVA films. Significant improvement in some of the mechanical properties of polymer composites was realized in comparison with PVA.     

Novel Poly(linolenic acid) Graft Copolymers: Synthesis,Characterization and Electrical Properties

A poly(linolenic acid)‐g‐poly(tert‐butyl acrylate) graft copolymer was synthesized from polymeric linolenic acid peroxide possessing peroxide groups in the main chain by free radical polymerization of tert‐butyl acrylate. Graft copolymers having structures of poly(linolenic acid)‐g‐poly(caprolactone)‐g‐poly(tert‐butyl acrylate) were synthesized from polymeric linolenic acid, possessing peroxide groups on the main chain by the combination of free radical polymerization of tert‐butyl acrylate and ring‐opening polymerization of ε‐caprolactone in one‐pot. The obtained graft copolymers were characterized by proton nuclear magnetic resonance, gel permeation chromatography, thermal gravimetric analysis, differential scanning calorimetry, and scanning electron microscopy techniques. Furthermore, Au/n‐Si diodes were fabricated with and without poly(linolenic acid)‐g‐poly(caprolactone)‐g‐poly(tert‐butyl acrylate)‐4 to form a new interfacial polymeric layer for the purpose of investigating this polymer's conformity in electronic applications. Some main electrical characteristics of these diodes were investigated using experimental current–voltage measurements in the dark and at room temperature.     

Effect of Silver Doping on the Physical and Electrical Properties of PLZT Ceramics

Additions of small amounts of silver to a PLZT dielectric with emphasis on the 88/12/70/30, Pb/La/Zr/Ti, composition were investigated. It was found that a few mole percent of Ag¹⁺ could be incorporated into the PLZT lattice as a large acceptor cation and that it tended to reduce the lead vacancies, which are normally generated by the substitution of La³⁺ in the PLZT dielectric. The addition, up to 2 mol% of silver, decreased the 25°C dielectric constant from 2300 to 1700. However, the temperature coefficient of capacitance was improved to ±5% between -55° and +125°C, and the dissipation factor was reduced from 1.5 to 0.5%. Although the gravimetrically measured lead loss appeared to depend on the relative vapor pressure of lead oxide during sintering, the compensation mechanism of Ag¹⁺ was not affected.     

Heteroarm Star-Shaped Poly (N-isopropylacryamide-co-itaconic acid) Copolymer Prepared by Glucose Core as ATRP Initiator

Star-shaped temperature- and pH-sensitive poly (N-isopropylacryamide-co-itaconic acid) copolymer is synthesized by atom transfer radical polymerization (ATRP) using 1,2,3,4,6-penta-O-Isobutyrylbromide-α-D-glucose as 5-Arm ATRP Initiator. For ATRP of itaconic acid (IA), carboxylic groups of IA are protected via silylation by hexamethyldisilazane (HMDS) using Fe₃O₄ as a magnetic catalyst. The polymerization is carried out in 2-propanol/toluene 50:50 (v/v) mixed solvent at 90°C. Structure of copolymers is studied with FT-IR, ¹H NMR, glass transition temperature (Tg), and scanning electron microscopy (SEM). Results of temperature, pH, and percentage variation on polymer structure and the effects on lower critical solution temperature (LCST), which is investigated with potentiometery and conductometry, show that LCST of copolymer is around body temperature and demonstrate the ability of this polymer in the design of controlled drug delivery systems. According to the obtained results from naltrexone release, the investigated star-shaped copolymer may have potential applications in the controlled release of drugs.     

Effect of Poly(L-lactic acid) on Hydrolytic Degradation of Poly(glycolic acid)

The in-vitro degradation behavior of poly(glycolic acid) (PGA) rods and the composite rods containing poly(L-lactic acid) (PLLA) were investigated via mass loss, pH value change, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Since the degradation rate of PLLA is lower than that of PGA, PLLA/PGA composite rods exhibit a slower degradation rate in comparison with PGA. This finding indicated that it was possible to control the degradation rate of the composites by changing their composition. This result indicates that this kind of composite biomaterial may be applicable to devices for the need of prolonged degradation.     

铜离子掺杂对高铁低钙水泥熟料性能的影响

基于C4AF可以提高水泥基材料的抗蚀性,以高铁低钙水泥熟料为研究对象,掺入不同含量的CuO,通过对熟料及其水化产物进行X射线衍射(XRD)、水化热、抗压强度、非蒸发水含量和固化氯离子能力等测试,探究Cu2+对高铁低钙水泥熟料水化性能与氯离子吸附固化能力的影响.结果发现,适量CuO的掺入促进了高铁低钙水泥熟料中C4AF的生成,降低了熟料液相的粘度,有利于C3S的晶粒生长,有利于提高高铁低钙水泥熟料的水化活性和固化氯离子能力,最佳掺量为0.2 wt％.     

可生物降解聚乳酸纳米粒的制备及表征

采用乳化 -溶剂蒸发法 ( O/W)制备聚乳酸 ( PLA)纳米粒 ,用透射电子显微镜和激光粒度仪对纳米粒进行了表征 ,纳米粒具有规整的球形且正态分布 ,同时从有机相和水相的体积比、聚合物的浓度、表面活性剂的选择及表面活性剂的浓度等几个因素对纳米粒粒径大小的影响作了较详细地讨论。有机相与水相的体积比从 1∶ 3减小到 1∶ 30 ,纳米粒的粒径从 ( 30 6.2 + 1 1 ) nm减小到( 1 87.1 + 2 .4) nm;聚合物在有机相的浓度从 1 %(质量分数 )增加到 5 %(质量分数 ) ,纳米粒的粒径从 1 94nm增加到 32 1 nm;随着水相中表面活性剂浓度从 0 .5 (质量体积分数 )增大到 3.5 %(质量体积分数 ) ,纳米粒粒径从 2 0 2 nm减小 1 78nm且有一个低的多分散指数。而且还比较了搅拌蒸发法和减压抽提法对纳米粒表面形态的影响