等规聚丙烯离聚体增容聚丙烯/尼龙11共混体系研究

以碘代等规聚丙烯为大分子反应中间体,通过季胺化亲核取代反应和点击化学反应,制备了N-甲基咪唑聚丙烯离聚体(IA)和邻巯基苯胺盐酸盐聚丙烯离聚体(IB),并将其作为等规聚丙烯/生物基尼龙11 (i PP/PA11)共混体系的增容剂.通过动态力学分析(DMA)、扫描电镜(SEM)和力学性能测试,对i PP/PA11/聚丙烯离聚体三元共混体系的相形态与性能进行了系统研究. DMA测试结果显示,2种聚丙烯离聚体使i PP/PA11共混体系的玻璃化转变温度Tg相互靠近;SEM结果显示,离聚体的加入使分散相粒子尺寸显著减小,两相界面作用力增加;力学性能测试表明,i PP/PA11/IA、i PP/PA11/IB三元共混体系的拉伸强度和冲击强度保持较好的水平.以上研究结果表明,IA和IB均可以显著改善i PP/PA11共混体系的相容性.     

含稀土离子液体[Cnmim][Ln（NO3）4]的合成、表征及荧光性能研究

以N-甲基咪唑,溴代烷烃和硝酸钠为原料,合成了5种离子液体[Cnmim]NO3(n=2,4,6,8,10;mim=N-甲基咪唑),并对离子液体进行了表征.用[Cnmim]NO3与硝酸铕、硝酸铽反应,得到了含稀土离子液体[Cnmim][Ln(NO3)4](Ln=Eu,Tb).利用电喷雾质谱对[Cnmim][Ln(NO3)4]的结构进行了表征,结果表明稀土离子与来自4个硝酸根的8个氧原子配位,形成[Ln(NO3)4]阴离子,阳离子为1-烷基-3-甲基咪唑.荧光研究表明,[Cnmim][Ln(NO3)4](Ln=Eu,Tb)的溶液存在较强荧光;温度和浓度影响荧光强度.     

新型双功能交联型阴离子交换膜的制备与性能

以2-甲基咪唑为原料合成2种离子液体前驱体1-烯丙基-2-甲基咪唑和1-丁基-2-甲基咪唑,以苯乙烯(St)和对氯甲基苯乙烯(VBC)为原料制备聚离子液体主链p(St-co-VBC),2种离子液体前驱体与聚离子液体主链发生季铵化反应铸膜,制备了交联结构和梳型侧链结构型阴离子交换膜(AEMs).通过傅里叶红外光谱、扫描电子显微镜和热重分析等考察了阴离子交换膜的结构、微观形貌、氢氧根离子传导率、热稳定性及碱性稳定性等性能.结果表明,AEMs含水率为36.7%~93.4%,离子交换容量为1.61~2.16 mmol/g,80℃时,p(St-co-VBC)-3型AEMs氢氧根离子传导率高达68.4 mS/cm,在1 mol/L NaOH溶液中碱性浸泡240 h后,氢氧根离子传导率仍高达52.2 mS/cm,具备良好的碱性稳定性.     

1,2-二甲基咪唑啉的合成及表征

对1,2-二甲基咪唑啉的合成进行了详细研究. 以甲胺水溶液和2-溴乙胺氢溴酸盐(1)为原料进行反应, 在两种原料物质的量之比为5∶1, 缓缓回流12 h的条件下, 得到N-甲基乙二胺(2), N-甲基乙二胺经过乙酸化得到N-甲基-N,N′-二乙酰基乙二胺(3), 然后, N-甲基-N,N′-二乙酰基乙二胺和氧化钙在高温下关环得到1,2-二甲基咪唑啉(4). 并对所得到的产物1,2-二甲基咪唑啉经元素分析, 1H NMR, IR和GC-MS得到了表征.     

离子液体表面活性剂烷基硫酸1-丁基-3-甲基咪唑鎓盐的合成及其在水溶液中的聚集行为

采用离子交换法,由氯化1-丁基-3-甲基咪唑鎓(C_4mimCl)和烷基硫酸钠合成了一系列无卤素的阴离子表面活性离子液体—烷基硫酸1-丁基-3-甲基咪唑鎓盐[C_4mim][C_nH_(2n+1)SO_4](n=8,12,16),利用表面张力仪、稳态荧光光谱等手段考察了表面活性离子液体在水溶液表面及体相中的聚集行为。结果表明,与传统无机反离子相比,有机咪唑阳离子[C_4mim]~+作为反离子的离子液体型表面活性剂具有较高的表面活性,[C_4mim]~+产生的氢键引起的抑制分子规则排列的作用小于其促进分子有序排列的疏水作用。长烷基链的阴离子是界面膜及胶束的主要组成成分,阴离子疏水烷基碳链的增长虽然可促进胶束的形成,但却在一定程度上抑制[C_4mim]~+参与界面或胶束的形成;阴离子所带烷基链越长,越不利于阳离子[C_4mim]~+参与界面膜或胶束的形成,界面膜或胶束中表面活性剂排布越松散,即界面张力越大,体系中胶束聚集数较小。     

咪唑类含能离子液体的合成及性能研究

以N-甲基咪唑、1,2-二甲基咪唑和2-氯乙醇为原料,经季铵化、硝化和复分解反应,合成了一系列咪唑类含能离子液体.通过紫外可见光谱、红外光谱、质谱、核磁共振和元素分析等对结构进行了表征.研究了其在常用有机溶剂中的溶解性,结果表明所合成的咪唑类含能离子液体在极性溶剂中具有良好的溶解性.采用热重分析法和差示扫描量热法研究了其热性能,结果表明所合成的含能离子液体具有良好的热稳定性,其中N-硝酰氧乙基咪唑硝酸盐的分解温度均在160℃左右,而N-羟乙基咪唑离子盐的分解温度均超过了190℃.差示扫描量热技术(DSC)实验表明,1-(2-硝酰氧乙基)-3-甲基咪唑硝酸盐和N-羟乙基咪唑类离子盐在二次升温过程中均发生了玻璃化转变,表现出了离子液体的特有性质.采用Kamlet-Jacobs方程估算了合成的含能离子液体的爆速和爆压等爆轰参数.     

2-取代-4(3H)-喹唑啉酮在Br(o)nsted酸性功能化离子液体中的微波合成

以N-甲基咪唑、吡啶为起始原料,合成了二种新型Br(o)nsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6 min即可完成,产率81%～95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变.     

2-取代-4(3H)-喹唑啉酮在BrФnsted酸性功能化离子液体中的微波合成

以N-甲基咪唑、吡啶为起始原料,合成了二种新型BrФnsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6min即可完成,产率81%～95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变.     

咪唑钴啉酯的合成及钴-氮键稳定性的研究

合成了维生素B~1~2(VB~1~2)模型分子-单腈N-甲基3-咪唑基钴啉酯高氯酸盐8。通过8在不同pH缓冲溶液中的UV-Vis谱,计算了Co-N键的平衡常数,独立配位体N-甲基咪唑与咕啉环中心钴原子配位键的键强与自身键连配位体的配位键强要弱。     

用于碱性膜燃料电池的新型聚苯醚阴离子交换膜的制备与性能

以2,6-二甲基聚苯醚(PPO)为原料, 经溴代及N-甲基咪唑季铵化反应, 制备了N-甲基咪唑季铵化PPO, 并进行了红外光谱(FTIR)和氢核磁共振波谱(¹H NMR)表征.所得季铵化产物与聚乙烯醇(PVA)按不同比例共混后用戊二醛交联成膜, 在碱性液中浸泡转化为OH^-型, 得到一系列阴离子交换膜.通过扫描电子显微镜(SEM) 、交流阻抗(AC)、拉伸实验和热重分析(TGA)等手段考察了膜的微观形貌及电导率、力学性能、热稳定性及耐碱性等性能.结果表明, 膜的外观形貌平整均一; 含水率为50.4%~151.2%; 溶胀度为79.2%~164.2%; 离子交换容量为0.47~1.52 mmol/g; 90℃时, M4膜的电导率高达49.1 mS/cm; 断裂伸长率达到128%, 极大改善了PPO膜应力易裂的状况.同时, N-甲基咪唑鎓基团分解温度达到170℃, 高于常用的阴离子交换膜中的季铵基团(120℃).在2 mol/L的NaOH溶液中浸泡192 h后, 电导率仅下降19%, 具备良好的耐碱性能力.     

Simultaneous Enhancement of Toughness and Strength of Stretched iPP Film via Tiny Amount of β-Nucleating Agent under "Shear-free"Melt-extrusion

Herein,isotactic polypropylene films with small β-nucleating agent content were fabricated via a melt-extrusion-stretched technology with intended "shear-free" in barrel and die.Compared with neat films,the tensile strength,elongation at break and strain energy density at break of iPP film with 0.05 wt％ β-nucleating agent are significantly improved by 13.8％,39.6％ and 90.6％,respectively,indicating the simultaneously enhanced toughness and strength.Additionally,the β-crystal content gradually increases with increasing β-NA content,while the relative total daughter content of α-and β-crystal exhibits opposite tendency.Moreover,nucleation and crystal growth induced by various β-NA contents are different.This work proves an efficient strategy to enhance mechanical properties of isotactic polypropylene film via controlling elongation flow and addition of appropriate β-NA content.     

磺化丁基橡胶离聚体及其共混物的动态力学性质

<正> 含10％摩尔以下的离子且主链为柔性的离聚体是一种热塑性弹性体。在动态力学性质方面呈现特殊的行为,表现在贮能模量(1gE′)与温度的关系中有橡胶态平台出现。最早Otocka等指出,(丁二烯-甲基丙烯酸)共聚物无橡胶态平台,经金属离子中和后产生橡胶态平台,且E′增加。Agarwal,Makowski等则报道磺化乙丙胶离聚体的橡胶态平台随离子含量提高而加宽,随硬脂酸锌的加入而缩短。Fitzgerald及Weisst结合X-射线小角散射研究了甘油及邻苯二甲酸二辛酯对磺化聚苯乙烯离聚体的动态力学性质的影响。     

Influence of ZnSt2 on structure of acrylate-based ionomers with different lanthanide (La(III)) ion and acid contents

A series of acrylate processing aid（ACR）-based ionomers with different lanthanide（La（Ⅲ）） ion and acid contents were synthesized,and the interaction between ionomer and zinc stearate（ZnSt₂） was investigated immediately after thermally annealing the ionomer/ZnSt₂（3/1 in weight） mixtures at 180℃.The results revealed that the ion groups in ionomer have a strong interaction with ZnSt₂.The annealed mixtures contained hot alcohol extractable and unextractable ZnSt₂.The melting of ZnSt₂ and the thermal behavior of the ionomer in the annealed mixtures were seriously influenced by the contents of La（Ⅲ） and acid in the ionomers.The ionomer containing 0.25 mmol/g acid and 0.37 mmol/g La（Ⅲ） has a detectable cluster phase.Annealing its ZnSt₂ mixture could break down the cluster phase and lower glass transition temperature of the ionomer matrix.However,washing away the extractable ZnSt₂ led to the reappearance of the cluster transition temperature and return of the glass transition temperature of matrix to the original position.     

含离子聚合物体系的动力学

离子作用的可逆性赋予了含离子聚合物丰富的力学和电学性能,使其广泛应用在高抗冲材料、记忆材料、自修复材料和智能响应材料等新兴领域.本专论结合作者近年的研究工作,介绍了含离子聚合物体系的构效关系和分子流变学,从3个方面展开:第1部分介绍了对于含离子聚合物的离子聚集状态的调控,和离聚物与聚电解质的相互转化;第2部分介绍了离子高度聚集的无规离聚物丰富的线性黏弹性,重点介绍了非缠结体系在链均一个离子浓度附近区域的溶胶凝胶转变以及缠结体系在平均每个缠结链段一个离子浓度附近区域的单平台到双平台模量的转变;第3部分介绍了如何进行分子设计,使得含离子聚合物成为有效的离子传输介质.最后总结了该研究领域的科学问题和面临的挑战.     

Deformation and fracture behavior of polystyrene ionomer and ionomer blends

The deformation and fracture behavior of sulphonated polystyrene ionomers, and of blends of these with polystyrene have been investigated. The microstructure of the ionomer, which varies with ion content, appears to have a significant effect on mechanical properties. Both tensile strength and toughness increase appreciably at ion contents near 5 mol%, where clusters become dominant over ion pairs and multiplets. In blends of the ionomers and polystyrene, phase separation occurs and the ionomer component appears in the form of fine particles dispersed in the polystyrene matrix. These particles possess a greater effective entanglement density than the matrix, as a result of ionic crosslinking, and they provide reinforcement against early craze breakdown and fracture. Tensile strength and fracture energy increase rapidly as the ionomer concentration in the blend is increased and they become essentially independent of blend ratio above about 10 wt% of the ionomer. Tests carried out on thin film specimens of the blends show that the dispersed ionomer particles adhere well to the matrix and contribute to the fracture energy both by inducing matrix crazing and by internal fibrillation within the particles.Dedicated to Professor Hans-Henning Kausch on the occasion of his 60th birthday.     

Thermal effect on C-H stretching vibrations of the imidazolium ring in ionic liquids

We have studied temperature dependent IR spectra of the C-H stretching modes of the imidazolium ring in [bmim][PF(6)], [bmim][Tf(2)N], [emim][Tf(2)N], [hmim][Tf(2)N], and [bmim][BF(4)]. Temperatures in this study are from 278 to 348 K at an interval of 10 K. Spectra of the C-H stretching modes have been deconvoluted using our previous computer program of the Voigt-lineshape function. Frequency shifts, Lorentzian spectral widths, and band absorbance were examined as a function of temperature. In order to interpret the observed behaviors, we have developed a simple mechanical model as well as a chemical equilibrium model. The model analyses suggest that enthalpy changes for the cluster and/or ion-pair breaking reactions in the liquid state are several kJ mol(-1) endothermic, and the degree of dissociations of ion pairs or hydrogen bonded clusters is in the range from 0.3 to 0.9 with different magnitudes for the five ionic liquids.     

Stability and growth behavior of transition metal nanoparticles in ionic liquids prepared by thermal evaporation: how stable are they really?

Recently we developed an access to metal- and metal-oxide colloids based on thermal evaporation of metals into ionic liquids (ILs). Here we present systematic studies on the long-time stability of gold and copper nanoparticles (NPs) in different ILs. The influence of metal concentration and temperature on the ripening of the as-prepared gold NPs in different ILs was investigated by transmission electron microscopy (TEM) and UV-vis absorption measurements. Short alkyl chain-length-methyl-imidazolium salts with weakly coordinating perfluorinated counter anions (PF(6), BF(4) or Tf(2)N, bis(trifluoromethanesulfonyl)amide) were found to be better stabilizers compared to ILs with cations bearing long alkyl chains (trihexyltetradecylphosphonium, 1-octyl-3-methylimidazolium) and anions of higher coordination strength (DCA, dicyanamide). In the latter ILs fast particle growth and agglomeration was observed. In the well-stabilizing ILs initially very small NPs form which undergo a similar ripening process at room temperature as at higher temperatures. The final particle size depends largely on the used IL and the metal and to a minor extent on the temperature. The metal concentration seems to be an unimportant factor.     

Nature and properties of ionomer assemblies. II

The principle subject in the current paper is to summarize and characterize the ionomers based on polymers and copolymers such as polystyrene (PSt), polyisoprene (PIP), polybutadiene (PB), poly(styrene-b-isobutylene-b-styrene) (PSt-PIB-PSt), poly(butadiene-styrene) (PB-PSt), poly(ethylene terephthalate) (PET), poly(butylene adipate) (PBA), poly(butylene succinate) (PBSi), poly(dimethylcarbosiloxanes), polyurethane, etc. The self-assembly of ionomers, models concerning ionomer morphologies, physical and rheological properties of ionomer phase and percolation behavior of ionomers were discussed. The ionomer phase materials and dispersions have been characterized by differential scanning calorimetry (DSC), small-angle X-ray catering (SAXS), small-angle neutron scattering (SANS), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), etc. The wide range of compositions, molecular architectures, and morphologies present in ionomeric disperse systems are of great interest. The research is particularly devoted to the potential application of these materials and an understanding of the fundamental principles of the ionomers. They are extremely complex systems, sensitive to changes in structure and composition, and therefore not easily amenable to modeling and to the derivation of general patterns of behavior. The reviewed data indicate that a large number of parameters are important in influencing multiplet formation and clustering in random ionomers. Among these are the ion content, size of the polyion and counterion, dielectric constant of the host, T(g) of the polymer, rigidity or persistence length of the backbone, position of the ion pair relative to the backbone, steric constraints, amount and nature of added additive (plasticizer), thermal history, etc.     

液晶离聚物--分子设计与热性能

综述了液晶离聚物的分子设计与液晶热性能的关系,一般主链液晶,离子在链中浓度增加,玻璃化温度（Ｔｇ）和熔点（Ｔｍ）下降,离子在端基,对Ｔｇ和Ｔｍ影响不大;离子对侧链淮晶的影响,取决于主链的柔顺性和离子在链中的位置等。一般情况下,无论对主链还是侧链液晶离聚物,随着离子在链中浓度增加,液晶相向各向同性液体转化温度（Ｔｉ）降低。     

Dynamic mechanical properties of polystyrene ionomers containing both carboxylate and sulfonate anionic groups

Polystyrene‐based ionomers possessing sodium methacrylate (MA) and sodium styrenesulfonate (SS) units in each polymer chain [poly(styrene‐co‐methacrylate‐co‐styrenesulfonate) (PSMA‐SS)] were synthesized. The dynamic mechanical properties of PSMA‐SS ionomers were studied and compared with those of styrene ionomers containing only MA (PSMA ionomer) or SS (PSS ionomer) units. It was observed that the ionic moduli of PSMA‐SS ionomers depended directly on the total ion content and that the ionic modulus was highest for the PSMA ionomer and lowest for the PSMA‐SS ionomer. The matrix T_gs of the three ionomer systems were found to be similar to each other; the cluster T_g of PSMA‐SS ionomer was higher than that of PSS ionomer at low SS contents but became closer to each other at high SS contents. In addition, the small‐angle X‐ray scattering study revealed that the multiplet size might be in the following order: PSMA‐SS > PSS > PSMA. This implied that at the same ion content, the fractions of cluster regions were smallest for PSMA‐SS ionomer in comparison with those of PSS or PSMA ionomers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012