双端氨基聚乙二醇的合成

聚乙二醇( PEG)与对甲苯磺酰氯(TsCl)进行醋化反应,制备出聚乙二醇对甲苯磺酸酯PEG-OTs(1)收率65％.在高压釜中,PEG-OTS 与氨水进行氨基化反应制备出双端氨基聚乙二醇Amino-PEG(2),收率70％,并一步研究了“酯化”和“氢基化”的合成原理.中间体PEG-OTs及产品Amino-PEG的结构...     

聚乙二醇化壳聚糖的合成

对壳聚糖C(6)-OH进行聚乙二醇醚化接枝,制备聚乙二醇化壳聚糖衍生物,以提高其作为新型抗肿瘤药物载体对病理部位的选择性。实验中,壳聚糖C(2)-NH_2和聚乙二醇单甲醚(MPEG)分别用邻苯二甲酸酐保护氨基和利用Arbuzov重排实现聚乙二醇单甲醚碘化,而后C(6)-OH与碘代聚乙二醇单甲醚(MPEGI)醚化、脱保护,得到6-O-聚乙二醇单甲醚壳聚糖(CS-MPEG)。通过FTIR和1H NMR,确证了最终产物的结构,通过1H-NMR计算得MPEG接枝率为78%。     

单端马来酰亚胺基功能化聚乙二醇的制备

以PEG2000为初始原料,通过与小分子的反应,将其一端羟基保留,得到NH2-PEG2000-OH,然后将NH2-PEG2000-OH与6-(马来酰亚胺基)己酸琥珀酰亚胺酯反应,得到单端马来酰亚胺基修饰的聚乙二醇(Mal-(CH2)5-CONH-PEG2000-OH)。经过1H NMR验证,结果表明,通过这条合成路线能够成功得到单端马来酰亚胺基功能化的聚乙二醇。     

高碘酸氧化法制备端氨基聚乙二醇的研究

单甲氧基聚乙二醇5000(m PEG5000)和对甲苯磺酰氯(p-Ts Cl)磺酸酯化,得到单甲氧基聚乙二醇对甲苯磺酸酯(m PEG5000-OTs),与乙醇胺亲核取代反应,获得末端具有β-氨基醇结构的聚乙二醇中间体,用高碘酸盐氧化,得相对分子质量5000的端氨基聚乙二醇(m PEG5000-NH2),总收率75.1%,产物结构通过IR和1H NMR进行表征。     

氨基化单甲氧基聚乙二醇的合成研究

首先合成了单甲氧基聚乙二醇对甲苯磺酸酯(mPEG-OTs),然后根据盖布瑞尔合成法原理,以邻苯二甲酰亚胺钾盐(PPI)为亲核试剂与mPEG-OTs反应,生成单甲氧基聚乙二醇的邻苯二甲酰亚胺衍生物(mPEG-PI),mPEG-PI与水合肼反应肼解生成伯胺,合成了一端为氨基的单甲氧基聚乙二醇(mPEG-NH2)。讨论了缚酸剂、溶剂、反应条件对反应的影响。通过红外、液质联用、核磁共振谱图证实了产物与目标分子的结构相吻合。     

聚乙二醇对甲苯磺酸酯的制备

标题化合物是制备多种末端功能化聚乙二醇衍生物的重要中间体。交流不同分子量的聚乙二醇和聚乙二醇单甲醚与对甲苯磺酰氯进行酯化的反应条件及提纯方法,制备出3个双(对甲苯磺酸)聚乙二醇酯,收率65%~80%;2个单对甲苯磺酸聚乙二醇单甲醚酯,收率55%~61%;其结构经1HNMR表征。     

氨基叠氮聚乙二醇的制备

以聚乙二醇1500为起始原料,经两步官能团转化得到双叠氮基聚乙二醇(N_3-PEG_(1500)-N_3),该中间体经有机相还原、水相终止,实现双叠氮基的单侧还原。反应选择性及转化率经液质联用(组分中代表性准分子离子峰的液相积分面积比例)进行评价。利用单因素实验,确定氨基叠氮聚乙二醇(NH_2-PEG_(1500)-N_3)最佳液液两相反应条件如下:N_3-PEG_(1500)-N_3与三苯基膦的物质的量比为1.0∶1.1,有机相为V(甲苯)∶V(二氯甲烷)=3∶2的混合溶液,水相为2.0 mol/L盐酸溶液,两相体积比1∶1,35℃下反应12 h,经柱分离提纯得NH_2-PEG-N_3,收率72%,单侧叠氮基还原选择性达97%。实验结果表明,该法制备NH_2-PEG_(1500)-N_3具有纯度高、方法简便等特点。产物经~1HNMR、~(13)CNMR、IR和HRMS进行结构确证。利用NH_2-PEG-N_3实现了叠氮封端功能化磷脂的合成。     

单分散聚乙二醇的高效合成

以廉价的2~4聚的聚乙二醇为原料，开发了一种基于环硫酸酯的单端延伸法合成单分散聚乙二醇的方法。以苄基作为保护基，重复利用环硫酸酯的亲核开环、水解反应对苄基化聚乙二醇的羟基端进行延伸，以55%～86%的产率得到苄基化的6~16聚的单分散聚乙二醇衍生物，最后通过催化氢化脱去苄基，以95%～99%的产率得到6~16聚的单分散聚乙二醇。中间体及终产物的结构均经NMR和MS确证。反应进程易于监控，反应效率高，无与目标产物的聚合度接近的聚乙二醇杂质，中间体及终产物易于分离纯化。     

聚乙二醇-双-全氟2-[(2-丙氧基)-丙氧基]丙酸酯的合成与性能

制备了聚乙二醇-双-全氟2-[(2-丙氧基)-丙氧基]丙酸酯(I),并考察其表面活性.全氟-2-[(2-丙氧基)-丙氧基]丙酰氟和聚乙二醇-400,在有机碱三乙胺的存在下,发生酯化反应,得到聚乙二醇-双-全氟24(2-丙氧基)-丙氧基]丙酸酯,并以红外光谱和核磁共振进行表征.结果表明:I水溶液的临界胶束浓度为0.54 ...     

一种水溶性含苯硼酸二嵌段共聚物的制备及表征

本研究首先通过原子转移自由基聚合(ATRP)方法制备了二嵌段共聚物,聚乙二醇-b-聚(甲基丙烯-2-甲氨基乙酯)(PEG-b-PDMAEMA),再通过对PEG-b-PDMAEMA的季胺化,制备了苯硼酸化的聚乙二醇-b-聚(甲基丙烯-2-甲氨基乙酯)(PEG-b-PBDMAEMA)。通过~1H-NMR谱图和GPC对PEG-b-PBDMAEMA进行结构表征,并利用DLS研究PEG-b-PBDMAEMA的水溶性。结果表明以季胺化为后改性手段,成功制备出水溶性良好的含苯硼酸二嵌段共聚物。     

Polyethylene glycol-water and polypropylene glycol-water solutionsas benign reaction solvents

Aqueous solutions of low molecular weight polypropylene and polyethylene glycol are proposed for use as novel, safe, environmentally friendly solvents. Not only are these solvents relatively nontoxic, but they are also nonvolatile, which eliminates the possibility of fugitive gaseous emissions. Many organic compounds have been found to be soluble in these polyglycol solutions; thus, they could be used as replacement solvents in various chemical processes. One use of the solvents could be as the medium for conducting chemical reactions, and this has been investigated. In particular, three classes of organic reactions, S N 1, S N 2, and Diels-Alder, have been conducted in the polyglycol solutions. Rate constants were obtained and compared to those for the traditional organic solvents. For the S N 1 reaction and the Diels-Alder reactions, the rate constants in the polyglycol solvents were greater than those found for the frequently used organic solvents.     

Zinc electrodeposition in the presence of polyethylene glycol 20000

The influence of polyethylene glycol 20000 (PEG₂₀₀₀₀) on the mechanism of zinc deposition and nucleation was studied by voltammetry, chronoamperometry, and atomic force microscopy (AFM). The electrodeposition of zinc in an electrolytic bath containing PEG₂₀₀₀₀ occurs via two reduction processes with different energies that involve the same species, ZnCl₄²⁻: the first reduction process occurs at E_PI′c = −1.25 V, SCE, whereas the second process, which corresponds to the bulk deposition of Zn, occurs at E_PII′c = −1.6 V, SCE without significant interference from the hydrogen evolution reaction. Analysis of chronoamperograms obtained in the absence and presence of PEG₂₀₀₀₀ indicates that distinct nucleation mechanisms are involved during the initial stages of Zn deposition. In the absence of PEG₂₀₀₀₀, the transients are consistent with the model of 3D diffusion-controlled nucleation. In the presence of PEG₂₀₀₀₀, however, the transients exhibit a more complex form involving two simultaneous nucleation and growth processes: 2D instantaneous nucleation limited by the incorporation of adatoms (2D_i-li) and a diffusion-controlled 3D nucleation mechanism (3D_-dc). Characterization of the surface morphologies of the zinc deposits by AFM imaging confirmed our conclusions drawn from the electrochemical studies. SEM analysis showed that the zinc coatings obtained in the presence of PEG₂₀₀₀₀ at −1.6 V, SCE are smoother and more compact.     

铸膜液浓度对聚醚砜超滤膜性能的影响

以聚醚砜(PES)为膜材料,聚乙二醇(PEG4000)为添加剂,N,N-二甲基乙酰胺(DMAc)为溶剂,用溶液相转化法制备了聚醚砜超滤膜.本实验主要研究的是聚醚砜(PES)和聚乙二醇(PEG4000)浓度对膜结构和性能的影响.得出制备聚醚砜超滤膜的最佳条件:PES浓度为15wt％～20wt％,PEG4000浓度为14wt％.     

Electrodeposited Palladium Nanoflowers for Electrocatalytic Applications

Palladium was electrodeposited on an electrochemically activated carbon black substrate using potentiostatic technique, with and without the addition of polyethylene glycol (PEG‐6000) as an additive. Scanning electron micrographs showed change in morphology of Pd from spherical to flower, with increasing additive concentration. As an electrocatalyst for oxygen reduction reaction (ORR), formic acid oxidation and CO stripping, Pd nanoflowers displayed three‐ to fourfold increase in electrocatalytic activity in comparison to the spherical Pd deposits in terms of electrochemical surface area (ESA) and mass specific current density. X‐ray diffraction (XRD) patterns showed, the introduction of additive with varying concentration effect the direction of Pd growth thereby changing the morphology from spherical to flower. The result demonstrates an increase in efficiency of Pd utilization achieved with the addition of PEG during electrodeposition, which could also be applicable to other precious metal electrocatalysts. A scheme for the change in Pd morphology during electrodeposition with additive is also proposed.     

不同分子量聚乙二醇对碳化硅喷雾造粒的影响

研究了不同分子量聚乙二醇（PEG）对浆料粘度及喷雾造粒粉体的失重、形貌、流动性的影响。结果显示：不同分子量的PEG对SiC均有一定的分散效果,但大分子的PEG由于分子量的缠绕作用使空间位阻效应降低。造粒粉的失重开嫂的温度随PEG分子量的增大而升高,但最大失重温度区间基本一致。不同分子量PEG对喷雾造粒和粉体流动影响不大,但成形效果不如使用聚乙烯醇。     

蒙脱土的有机复合改性及其表征

采用有机复合改性的方法制备了改性蒙脱土，并对其进行了表征。结果表明：通过十六烷基三甲基溴化铵和聚乙二醇(PEG)复合物的有机改性，使蒙脱土层间距离有了较大程度的提高，同时使该有机蒙脱土中有机物含量提高；在研究范围内，聚乙二醇摩尔质量越小，增大蒙脱土的层间距的作用越明显。     

101-A型不饱和聚酯树脂的研制

介绍了用ＰＥＴ废料制备１０１—Ａ型不饱和聚酯树脂工艺，确定了配料及反应温度。对该不饱和树脂的热稳定性及腐蚀性进行了实验。其性能优于市场上通用型（邻位）不饱和树脂。     

Heterogeneous photocatalytic degradation of ethylene glycol and propylene glycol

The photocatalytic decomposition of ethylene glycol and propylene glycol was investigated by using UV-illuminated TiO₂ and metal-loaded TiO₂ catalysts. The effects of pH, initial concentration, and wavelength of light on the decomposition rate of the glycols were explored. Platinum-and palladium-loaded TiO₂ catalysts enhanced the rates of photodecomposition compared to unloaded TiO₂. The glycols were oxidized primarily to carbon dioxide and water. Formaldehyde was found to be an important reaction intermediate. A detailed chemical reaction mechanism for the destruction of ethylene glycol and propylene glycol in water via free radical pathway and trapped hole reactions at the particle surface is proposed.     

聚乙二醇/硬脂酸复合体系用于卷烟香料缓释的机理研究

以聚乙二醇/硬脂酸复合体系为基质型缓释材料,以陈皮/薄荷复合香精为被缓释香料,深入研究基质材料的组成、相结构、升温相变行为对香料缓释过程的影响,揭示了聚乙二醇/硬脂酸复合体系的常温锁香机理和香料缓释机理。缓释基材中的晶区通过晶格排列和晶区内分子相互作用储存少量香料分子,其余大量香料分子则通过强氢键相互作用附着于疏松的非晶区。常温下热力学稳定,香料分子得以稳定储存。卷烟燃吸的升温过程伴随着基材的熔融和氢键相互作用的解离,同时以分段释放的方式控制香料分子的缓释。香料被加入基材后,两个释放阶段的最大释放速率及释放量均有明显降低,说明基材对于香料的释放存在明显的抑制作用。     

含催化剂的乙二醇和二甘醇黏度测定及关联

在常压、313~413 K下,采用ND J-1旋转式黏度计,测定了含NY2催化剂的乙二醇和二甘醇的黏度.采用黏度Andrade关系式,将黏度数据与NY2催化剂质量分数和温度进行关联,得到经验关系式.结果表明,由经验方程计算值与实验结果基本相符,为催化水合制乙二醇的反应器设计和优化分离设备提供必要的基础数据.