UV光引发的丙烯酰胺反相乳液聚合

报道了不透明丙烯酰胺反相乳液体系的UV光引发聚合新方法 .使用普通中压汞灯并辅以适当搅拌 ,UV光引发丙烯酰胺 水 煤油 Span80 +OP 10反相乳液聚合可在 2 0min左右完成 ,所得聚合物分子量达千万 ;聚合过程中不存在恒速期 ,扫描电镜未观察到聚合前后乳胶粒径有数量级的变化 ,表明聚合反应以单体液滴成核为主 .此外 ,考察了光引发剂类型及浓度、单体浓度、乳化剂用量、反应温度等对聚合反应的影响 ,结果表明不同光引发剂的引发活性为Irgacure 2 95 9>(ITX +EDAB) >BDK ,引发剂浓度增加 ,反应速度先增加而后降低 ,存在一最大值 ;单体浓度增加 ,反应速度加快 ,聚合物分子量提高 ;乳化剂用量增加 ,反应速度加快而分子量变化不明显 ;聚合表观活化能为 13 34kJ mol.     

脂环族环氧树脂和螺环原碳酸酯的光引发正离子共聚合

<正> 无收缩单体-1,6,8,13-四氧螺[7,7]十三碳烷(SOC_7)和3,4-环氧基环己烷甲酸3',4'-环氧基环己烷甲酯(ERL-4221)的光引发正离子共聚合的研究结果表明,少量SOC_7加到ERL-4221体系中可抑制固化收缩没有明显降低热性能。ERL-4221对SOC_7的合适克分子比为4比1,由此得到T_g为203℃而聚合时体积收缩为4.4％的交联共聚物。     

A Unified Mechanism for the PhCOCOOH-mediated Photochemical Reactions: Revisiting its Action and Comparison to Known Photoinitiators

Since 2014, we have introduced in literature the use of phenylglyoxylic acid (PhCOCOOH), a small and commercially available organic molecule, as a potent promoter in a variety of photochemical processes. Although PhCOCOOH has a broad scope of photochemical reactions that can promote, the understanding of its mode of action in our early contributions was moderate. Herein, we are restudying and revisiting the mechanism of action of PhCOCOOH in most of these early contributions, providing a unified mechanism of action. Furthermore, the understanding of its action as a photoinitiator opened a new comparison study with known and commercially available photoinitiators.     

Fast preparation of photopolymerized poly(benzyl methacrylate-co-bisphenol A dimethacrylate) monoliths for capillary electrochromatography

A novel porous polymer monolith was prepared in situ in a fused-silica capillary using photoinitiated polymerization. Bisphenol A dimethacrylate (BPADMA) was selected as a crosslinker, copolymerized with benzyl methacrylate (BMA) in the presence of a binary porogenic solvent consisting of cyclohexanol and 1-decanol in ≤10 min. The resulting poly(BMA-co-BPADMA) monoliths exhibited good permeability and mechanical stability. Mixtures of alkylbenzenes, polycyclic aromatic hydrocarbons (PAHs) or phenolic compounds were successfully separated by CEC. A similar monolith was also prepared with ethylene dimethacrylate (EDMA) as the crosslinker instead of BPADMA to compare the separation ability of the resulting monoliths. The results indicated that poly(BMA-co-BPADMA) monoliths have better selectivity for aromatic analytes and greater chromatographic stability in higher aqueous mobile phase.     

多元丙烯酸酯泡沫制备中的溶剂效应

 以季戊四醇四丙烯酸酯（PETA）为聚合单体，安息香乙醚为引发剂，通过紫外光引发生成凝胶，通过真空干燥得到PETA泡沫材料。通过理论计算和实验确定的多元丙烯酸酯交联聚合物的溶解度参数值为19.0左右，含有苯环的脂肪烃和酮类的溶剂会导致引发剂“失活”，而卤代烃、酯、醚和酰胺类溶剂能够保持引发剂的“活性”。     

A cation-exchange material for protein separations based on grafting of thiol-terminated sulfopropyl methacrylate telomers onto hydrophilized monodisperse divinylbenzene particles

A strong cation-exchange separation material has been prepared from monodisperse divinylbenzene particles modified by a "grafting to" approach, utilizing as anchoring points epoxy groups introduced onto the surface of the particles via oxidation of residual vinyl groups. The grafted chains consisted of thiol-terminated telomers of sulfopropyl methacrylate prepared by iniferter mediated polymerization, and grafting was performed by reaction of the corresponding thiolate anion with the surface epoxy groups. Attachment through epoxy moieties that were subsequently converted into 2,3-propanediol groups increased the hydrophilicity of the polymeric particles and incubation experiments showed no signs of the proteins denaturing on the column during an extended contact time of 1 h at room temperature. The performance of the grafted material was demonstrated by the chromatographic separation of cytochrome C, lysozyme, myoglobin, and ribonuclease A, in a cation-exchange mode.     

一种新型的可见光诱导电子转移生酸体系的研究

对 4种分子内共轭的电荷转移化合物和取代的双 (三氯甲基 ) 2 ,4,6 三嗪分子间的光诱导电子转移和光生酸反应进行了详细研究 .通过荧光猝灭和体系荧光随时间的变化可看到作为电子受体的三嗪分子和作为电子给体电荷转移化合物间的光诱导电荷转移作用 .在对体系酸度的测定中 ,可清楚地看到体系经光照后所发生的变化 .对所研究生酸体系引发酚醛树脂 六甲氧基甲基三聚氰胺交联反应的能力进行了初步研究 .对可能发生的反应机制进行了讨论     

Enzyme-assisted Photoinitiated Polymerization-induced Self-assembly in Continuous Flow Reactors with Oxygen Tolerance

Polymerization-induced self-assembly(PISA) is an emerging method for the preparation of block copolymer nano-objects at high concentrations. However, most PISA formulations have oxygen inhibition problems and inert atmospheres(e.g. argon, nitrogen) are usually required. Moreover, the large-scale preparation of block copolymer nano-objects at room temperature is challenging. Herein, we report an enzyme-assisted photoinitiated polymerization-induced self-assembly(photo-PISA) in continuous flow rea...     

胶束体系中光敏聚合的研究 Ⅶ．微泡水溶液体系中光聚合的研究

研究了在双十六烷基二甲基溴化铵（ＤＣＤＡＢ）形成的微泡溶液中，二苯酮（ＢＰ）／三乙胺（ＴＥＡ）体系的光化学初级反应和引发ＭＭＡ光聚合反应．动力学实验结果表明，ＤＣＤＡＢ微泡对聚合反应有显著的催化作用，使聚合速度提高近４倍左右，其效果和离子型胶束的催化作用结果相近．由ＤＣＤＡＢ微泡中光聚合得到的产物ＰＭＭＡ，具有较高的结构规整性，它的间同和全同结构可达７０％左右．