Macromolecular crosslink of imidazole functionalized poly(vinyl alcohol) and brominated poly(phenylene oxide) for anion exchange membrane with enhanced alkaline stability and ionic conductivity

Anion exchange membranes (AEMs) are important energy conversion device for fuel cell applications, where the overall redox reaction happened. Both alkaline stability and ionic conductivity should be considered in the long-term use of fuel cells. In this work, imidazole functionalized polyvinyl alcohol was designed as the functional macromolecular crosslinking agent to fabricate crosslinked AEMs with brominated poly(phenylene oxide) matrix. Benefitting from the macromolecular crosslinked structure, the membranes displayed enhanced ionic conductivity and alkaline stability at elevated temperature. Moreover, membrane with ion exchange capacity of 1.54 mmol/g displayed ionic conductivity of 78.8 mS/cm at 80 °C, and the conductivity could maintain 75% of the initial value after immersion in 1 M NaOH solution at 80 °C for 1000 h. Moreover, a peak power density of 105 mW/cm² was achieved when the assembled single cell with c-91 was operated at 60 °C. These results indicated that the construction of macromolecular crosslinked AEMs have great potential in the practical application of anion exchange membranes fuel cells.     

Methacrylated calix[4]arene phosphonic acids as functionalized crosslinker for radical polymerization

We describe the synthesis of 5,11,17,23‐tetra‐tert‐butyl‐25,27‐dioxypropylphosphonic acid‐26,28‐dimethacryloyloxy‐calix [4]arene and 5,11,17,23‐tetra‐tert‐butyl‐25‐oxypropylphosphonic acid‐27‐hydroxy‐26,28‐dimethacryloyloxy‐calix[4]arene starting from para‐tert‐butyl‐calix[4]arene. The complete reaction was proved by matrix‐assisted laser desorption ionization time of flight mass spectrometry and nuclear magnetic resonance spectroscopy. The influence of these compounds on the kinetics of the radical polymerization of methyl methacrylate was shown by dilatometry. Furthermore, the adhesive properties of dental adhesives containing these calix[4]arene derivatives were investigated. Copyright © 2012 Society of Chemical Industry     

Visibly transparent conjugated polymers based on non-alternant cyclopenta-fused emeraldicene for polymer solar cells

In this study, we synthesized two emeraldicene (EMD)-based conjugated polymers, PBTEMD and PFEMD, through polymerization of 4,7-di(thien-2-yl)benzo[c][1,2,5]thiadiazole and 9,9-bis(2-ethylhexyl)-9H-fluorene, respectively. We then blended these EMD-derived polymers (as electron-donating materials) with [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM) in the active layers of polymer solar cells (PSCs) and investigate their optoelectronic properties and related photovoltaic performance. To best of our knowledge, this study is the first to use EMD derivatives for PSC applications. We compared the molecular structures, absorption behavior, energy levels, thermal properties, and thermal stability of these two polymers to determine their suitability for use in PSCs. The main absorption of PFEMD was in the near-IR spectrum (600–800 nm). We observed a transparency of greater than 80% for the blend film of PFEMD having a thickness of 95 nm; the constructed device exhibited a power conversion efficiency (PCE) of 2.5% and the transparent PFEMD:PC₆₁BM-derived device exhibited a PCE of 1.2% under AM 1.5 G irradiation (100 mW cm⁻²). We observed a significant improvement in thermal stability for the device incorporating the additive crosslinker TBT-N₃; it retained approximately 60% of its initial PCE after accelerated heating (150 °C) for 18 h. In contrast, the PCE of the corresponding normal device decayed to 0.01% of its initial value.     

低温固化环氧阴极电泳涂料的大分子交联剂的制备

首先以聚乙二醇200(PEG-200)、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)为原料合成了末端为异氰酸根(—NCO)的预聚体,再以N-甲基二乙醇胺(MDEA)为封端剂对—NCO进行全封端反应。通过添加适量的亲水性DMPA,提高了封端大分子的自乳化性能,制备出全封闭型异氰酸酯大分子(P-M-I)乳液,以其作为环氧阴极电泳漆低温固化的交联剂。应用FT-IR、DSC、TG、TEM、粒径分析等检测手段对全封闭型大分子及其乳液进行了结构与性能表征。将其与胺化环氧树脂乳液进行共混,制备了低温固化环氧阴极电泳涂料。通过电泳涂装的金属样片在124～130℃烘烤30 min可完全固化成膜。实验结果表明:该大分子交联剂显著降低了电泳涂料的固化温度,涂膜外观平整光亮、附着力好、铅笔硬度达2H,综合性能良好。     

交联改性苯丙乳液在水性油墨中的应用

分别以邻苯二甲酸二烯丙酯(DAP)、杂环甲基丙烯酸酯单体(TRM WAM Ⅲ)和乙酰乙酸基甲基丙烯酸乙酯(AAEMA)作为传统苯丙乳液的交联改性剂,采用预乳化半连续乳液聚合法制备交联改性苯丙乳液;然后以此为连接料,制备水性油墨.研究了传统苯丙乳液、交联改性苯丙乳液以及进口同类产品对水性油墨的摩擦牢度、稳定性能和耐水性能...     

内交联型复合薄膜用水性聚氨酯胶粘剂的研制

通过改变羧基含量(COOH%)、异氰酸酯基(-NCO)与羟基(-OH)的摩尔比(R值)、交联剂用量,考察了它们对聚氨酯乳液的粘度、胶膜的耐水性及复合薄膜T剥离强度的影响,合成了一种内交联型复合薄膜用水性聚氨酯胶粘剂.结果表明:乳液粘度随COOH%的增大而增大,随R值的增大而减小;随着COOH%的增加,胶膜的吸水率逐步增加,但随着R值或交联剂用量的增加而减小;R值或COOH%发生变化,T剥离强度也跟着发生改变;并且,交联剂能起到提高T剥离强度的作用,且当交联剂含量为9%最佳.     

环氧改性水性聚氨酯涂料的合成研究

研究旨在探索水性聚氨酯的合成工艺,合成出水性聚氨酯分散体,并通过引入环氧树脂E-20,内交联剂TMP,采用小分子扩链剂BDO等,进行乳液共聚合等手段,达到对水性聚氨酯结构的交联改性,从而得出了合理配方及适宜的反应条件。当E 20含量6.0%～8.0%;DMPA加入量7.0%～8.0%;EDA用量1.0%;中和度90%～100%时,乳液性能最佳。     

有机硅密封胶粘接聚烯烃材料的研究

研究了不同类型的有机硅密封胶对PE、PP材料的粘接性能,结果表明交联剂和界面因素是影响有机硅密封胶粘接性能的主要因素。根据研究结果设计合成自催化交联型有机硅密封胶和有机硅复合密封胶,并研究它们的性能。     

HPAM的相对分子量及电解质对LPS封堵性能的影响

采用微孔滤膜过滤法研究了在部分水解聚丙烯酰胺(HPAM)与交联剂柠檬酸铝(A lC it)的交联比确定的情况下,HPAM的相对分子量以及电解质对交联聚合物溶液(LPS)封堵性能的影响。结果表明,随着HPAM的相对分子质量的增大,HPAM与A lC it反应的时间增加,同时通过3μm微孔滤膜的过滤时间先增加后降低。LPS体系中电解质存在一个最佳的影响范围,当电解质(氯化钠、钙镁离子共同影响)的含量在5000~6000 mg/kg时,仍然可以得到稳定的胶态分散体系,且体系对多孔介质有较好的封堵效果。     

交联剂对魔芋超强吸水剂凝胶强度和吸水倍率的影响

以魔芋葡甘聚糖为基体,丙烯酸为单体,过硫酸钾为引发剂,分别以N,N’-亚甲基双丙烯酰胺(MBA)、甘油、聚乙二醇600(PEG600)、Ca(NO3)2.4H2O为交联剂,制备魔芋超强吸水树脂(KSAP),测试其凝胶强度和吸水倍率,同时对其进行红外光谱结构表征。实验表明,以MBA为交联剂制得的KSAP的凝胶强度最大,可达到153.7g/cm2,以甘油为交联剂制得的KSAP的吸水倍率最高,可达1201g/g。