聚乙二醇的应用与合成进展

对聚乙二醇的应用及生产情况作了简介 ,介绍了由环氧乙烷与水 ,或乙二醇经分步反应合成聚乙二醇的工艺 ,重点介绍了以甲醛为原料合成乙二醇的四种方法。认为以价廉的C1原料生产聚乙二醇 ,具有潜在的市场前景。     

聚乙二醇对直接合成聚乳酸-聚乙二醇的影响

为了得到综合性能较佳的生物降解材料聚乳酸-聚乙二醇(PLEG),以SnO为催化剂．直接以外消旋乳酸单体为原料,与不同数均分子量(Mn)的聚乙二醇(PEG)共聚合,通过直接熔融共聚法,在165℃、70Pa下．反应15h,合成了系列PLUG。用特性黏数测试、傅里叶变换红外光谱、核磁共振氢谱、差示扫描量热法、X射线衍射、接触角测试等手段对其进行表征,发现PEG的Mn为1000时,特性黏数最大,为0．4009dL/g,且亲水性得到改善。     

马来酸单聚乙二醇单甲醚酯的合成工艺

在自制催化剂、溶剂甲苯存在下,由马来酸酐与聚乙二醇单甲醚(400)通过直接酯化法合成马来酸单聚乙二醇单甲醚酯。当马来酸酐与聚乙二醇单甲醚摩尔比为(1.05—1.1)∶1时,控制温度100—105℃,反应7 h,合成的马来酸单聚乙二醇单甲醚酯的产率可以达到98%。通过红外光谱分析,发现所合成的酯的官能团分布和进口日本酯(NKesterM-90)非常接近,证明所合成的马来酸单聚乙二醇单甲醚酯满足预定的制备要求。     

Modification of unsaturated polyesters using polyethylene glycol

Abstract

The fracture toughness and impact resistance of rigid unsaturated polyesters can be modified by various physical and chemical methods. In this study, flexible unsaturated polyesters were prepared by condensation polymerisation of maleic anhydride, phthalic anhydride and propylene glycol in the presence of polyethylene glycol. By this method, copolymers of unsaturated polyesters with polyethylene glycols of different molecular weights were prepared. A two stage process was used for the synthesis, which resulted in segmental structures containing alternating rigid cross-linked segments and linear soft segments displaced regularly in the polymer chain. Properties such as tensile strength, tensile modulus, elongation at break, toughness, impact strength, surface hardness, abrasion resistance and water absorption were tested after the resin was cured in appropriate moulds and compared with those of the control resin. Polyethylene glycols of lower molecular weight (～ 200) impart flexibility to the polyester chains and increase fracture toughness and impact resistance of rigid unsaturated polyester without seriously affecting other properties. Glass reinforced specimens prepared using the modified resin also show improved toughness and elongation at break.     

聚乙二醇介质中纳米Fe-Mn催化剂的F-T合成反应性能

采用化学还原法在乙二醇/水混合溶剂中制备纳米Fe-Mn催化剂,考察其在液态聚乙二醇中的F-T合成反应性能。透射电子显微镜、X射线衍射、穆斯堡尔谱和X射线光电子能谱等表征结果表明,纳米Fe-Mn催化剂粒径为(20~50)nm,具有铁磁性非晶结构,Mn主要富集在催化剂表面,Mn的加入使Fe更富电子,催化剂更易碳化。纳米Fe-Mn催化剂表现出很高的F-T反应活性,Mn的加入有利于催化剂的链增长反应,使产物分布向重质烃方向偏移。     

Solvothermal synthesis of CdS nanowires templated by polyethylene glycol

CdS nanowires were solvothermally synthesized from Cd(NO₃)₂ and S powder using ethylenediamine as a solvent and polyethylene glycol (PEG) as a template. Hexagonal CdS with P6₃mc space group was detected using XRD and SAED, results which are in good accordance with those obtained by the simulation. SEM, TEM and HRTEM revealed the gradual development of nanowires in the [0 0 1] direction with a number of atoms aligning in a crystal lattice. Raman spectra of different products showed the fundamental and overtone modes at the same wavenumbers of 300 and 601 cm⁻¹, respectively. Their relative intensities at different molecular weight PEG were influenced by the anisotropic geometry of the products. Their photoluminescence peaks were detected at the same wavelengths of 518 nm. A formation mechanism for CdS nanowires was also proposed to relate to the experimental results.     

Carboxylic acids and polyethylene glycol assisted synthesis of nanocrystalline nickel ferrites

Different synthesis methods for the preparation of nanocrystalline nickel ferrites are reported: the thermal decomposition of precursors, made of: (i) metal-nitrate salts with carboxylic acids (citric, malonic and tartaric), and (ii) metal-nitrate salts and polyethylene glycol (PEG), in the presence of potassium chloride as a capping agent. The as-prepared gel precursors were characterized by TGA/DTA, while the samples obtained after annealing at 450 °C were investigated by FTIR, FESEM, XRD and Mössbauer spectroscopy. Regardless of the type of carboxylic acid used, nanocrystallites prepared by (i) method are similar in size (11–16 nm), while the method (ii) gives crystallites ∼33 nm in size with negligible microstrain. The differences in the lattice parameter, ranging from 8.3369(2) to 8.3574(2) Å, result from cation distribution, nonstoichiometry and structural imperfections in the nickel ferrite nanoparticles. The Mössbauer spectra analysis indicates existence of large distortions of tetrahedral and octahedral sites in these spinel compounds.     

Mixing strategies for zinc oxide nanoparticle synthesis via a polyol process

We report on the effect of mixing on the morphology of ultrafine zinc oxide nanoparticles synthesized via a polyol process using zinc acetate and water in a diethylene glycol medium. Three mixing strategies were considered: stirred batch, T‐mixer, and impinging free jets. The particle granulometry was accessed using the transmission electron microscopy and x‐ray diffraction methods. The nanoparticle size and polydispersity decreased with an increase in the local dissipated energy. In particular, the polyol process conducted in the same chemical environment at 353 K did not lead to the observation of nanoparticles in the stirred batch reactor but resulted in unconventionally small 6‐nm particles in the T‐mixer and impinging jet configurations. This result is apparently related to the micromixing eddy geometry described by the Kolmogorov length. The hydrodynamic flow patterns and energy dissipation were obtained from computational ?uid dynamics simulations, which are essential in the design, optimization, and scale‐up of the polyol process. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1708–1721, 2015     

Preparation of micro particles of functional pigments by gas-saturated solution process using supercritical carbon dioxide and polyethylene glycol

Particle design is presently a major development of supercritical fluids applications, mainly in the paint, cosmetic, pharmaceutical, and specialty chemical industries. The particles from the gas-saturated solutions (PGSS) process were used to micronize the functional compounds, fucoxanthin and astaxanthin. Fucoxanthin was extracted from brown seaweed using supercritical carbon dioxide (SC-CO₂) at 20 MPa and 45 °C. The particle formation of functional pigments with biodegradable polymer, polyethelene glycol (PEG) was performed by PGSS using SC-CO₂ in a thermostatted stirred vessel. Different temperatures (40 and 50 °C) and pressures (10–30MPa) were applied to optimize the conditions for the formation of functional pigment particles. Two nozzles of different diameter (250 and 300 μm) were used for PGSS and the reaction time was 1 hr. The average diameter of the particles obtained by PGSS at different conditions was about 0.78–1.42 μm.     

聚乙二醇单甲醚对甲苯磺酸酯的制备

以相对分子量2 000的聚乙二醇单甲醚(mPEG)与对甲苯磺酰氯(TsCl)为原料,再以三乙胺(TEA)为缚酸剂,进行亲核取代反应制备聚乙二醇单甲醚对甲苯磺酸酯(mPEG-OTs)。运用元素分析检测羟基转化率以及评价反应结果,通过单因素和正交实验来确定不同条件对羟基转化率的影响。结果表明,制备mPEG-OTs最佳工艺为:反应时间12 h,n(mPEG)∶n(TsCl)∶n(TEA)=1∶5.5∶5.5,反应温度为25℃。并通过IR与~1H NMR确定目标产物。     

A facile synthesis method of nickel nanotubes assisted by polyethylene glycol

Using an easy and general way, magnetic metal nickel nanotubes are successfully fabricated by adding polyethylene glycol (PEG200, PEG2000, and PEG20000) in the common electrolyte solution combined with electrodeposition technique. This method is very easy, effective, and facile. Especially, the pore wall of the template need not be modified, and their wall thickness can be effectively controlled by adjusting the experimental parameters, such as the electric current density, the concentration of polyethylene glycol, and the electrodeposition time. The possible formation mechanism is proposed. The magnetic measurement of Ni nanotubes indicates that the difference of the polymers used in the preparation does not have a notable effect on their magnetic properties. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Biomimetic synthesis of spherical nano-hydroxyapatite in the presence of polyethylene glycol

Spherical nano-hydroxyapatite (nano-HA) was synthesized successfully by a biomimetic method using Ca(NO₃)₂·4H₂O and (NH₄)₃PO₄·3H₂O as reagents in the presence of polyethylene glycol (PEG). The crystalline phase, microstructure, chemical composition, and morphology of the obtained samples were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The results show that spherical nano-HA with diameter of 30–50 nm can be synthesized in the presence of a certain concentration (2–6%) of PEG. The crystallinity of HA powder synthesized in the presence of PEG was higher than that synthesized in the absence of PEG, but the crystallinity of HA reduced with increasing the concentration of PEG. The electrical conductivity (EC) of the solution revealed that PEG reduced the transfer rate of Ca²⁺ in the process of HA crystallization, indicating the interaction between PEG and HA. The possible mechanism of formation spherical nano-HA was discussed.     

聚乙二醇单甲醚对甲苯磺酸酯的制备

以相对分子量2 000的聚乙二醇单甲醚(mPEG)与对甲苯磺酰氯(TsCl)为原料,再以三乙胺(TEA)为缚酸剂,进行亲核取代反应制备聚乙二醇单甲醚对甲苯磺酸酯(mPEG-OTs)。运用元素分析检测羟基转化率以及评价反应结果,通过单因素和正交实验来确定不同条件对羟基转化率的影响。结果表明,制备mPEG-OTs最佳工艺为:反应时间12 h,n(mPEG)∶n(TsCl)∶n(TEA)=1∶5.5∶5.5,反应温度为25℃。并通过IR与¹H NMR确定目标产物。     

聚乙二醇相变储能材料研究进展

聚乙二醇相变材料是一类相变焓较高、热滞后效应低的储能材料。本文综述了聚乙二醇相变储能材料的研究进展,重点论述了其制备方法、应用及展望。     

氮气增强溶液雾化技术制备聚乙二醇微粒

以超临界流体增强溶液分散技术为基础,用N2取代C02以实现该过程更好的雾化效果.实验研究以聚乙二醇(PEG6000)/丙酮溶液制备PEG微颗粒,探讨预膨胀压力和溶液流量对粒径及粒径分布的影响.结果表明,超临界N2增强的溶液雾化技术可以制得形态基本上为球形的PEG微粒,并且粒径分布可以方便地控制在1～5μm.PEG微粒随预膨胀压力增大而减少,粒径分布变窄;低PEG/丙酮溶液流量下制备的微粒粒径分布较窄.     

Preparation of ZrC/SiC porous self-supporting monoliths via sol-gel process using polyethylene glycol as phase separation inducer

We present a straightforward method via sol-gel process using polyethylene glycol (PEG) as phase separation inducer to prepare zirconium carbide/silicon carbide (ZrC/SiC) porous monoliths. Organic/inorganic hybrid gels are prepared using zirconium oxychloride, furfuryl alcohol, and tetraethyl orthosilicate as major starting materials. In the presence of PEG, crack-free hybrid monoliths are obtained by drying the wet gels under ambient pressure, whereas in the absence of PEG, the wet gels break into pieces as expected. PEG plays a key role in maintaining the macroscopic shape of the monoliths. After ceramization at 1300–1500?°C, ZrC/SiC porous monoliths are obtained. SEM and mercury intrusion porosimetry data show that PEG also has strong influence on the microstructures of the monoliths. The compressive strengths of the ceramic monoliths are in the range of 0.3 to 0.7?MPa. And their compressive behavior starts to differ due to the changes in their microstructures, especially the pore structure.     

One-step synthesis of silver nanoparticles embedded with polyethylene glycol as thin films

Silver nanoparticles (Ag NPs) embedded and stabilized with polyethylene glycol (PEG) were synthesized as colloids by heating and exposure to sunlight (direct and indirect) irradiation as green method. The deposition of Ag NP-PEGs onto Si-wafers was also made using the electrospray ionization deposition technique. The generating of Ag NP-PEGs as colloids was examined by UV–visible spectroscopy (UV–Vis) and transmission electron microscopy (TEM). The chemical composition of the resulted nanocomposites was evaluated by Fourier transform infrared (FTIR) and that of thin-film surfaces by X-ray photoelectron spectroscopy. Structure–property relationships of Ag-PEG nanocomposites prepared by heating were discussed in dependence on the time of heating. The UV–visible results confirmed the successful synthesis of spherical Ag NPs with absorption peaks at a wavelength of λ = 413 nm for the heating method and at λ = 418 as well as 449 nm for direct and indirect exposure to the sunlight. Ag-PEG nanocomposite thin films showed excellent antimicrobial activity. These results revealed that the Ag-PEG nanocomposites thin films can be used as potential materials in biomedical applications.     

Co-precipitation of loperamide hydrochloride and polyethylene glycol using aerosol solvent extraction system

The co-precipitation of loperamide hydrochloride (LPM) and polyethylene glycol (PEG) using aerosol solvent extraction system (ASES) was examined. Scanning electron microscopy — energy dispersive X-ray spectroscopy (SEM-EDS) analysis showed that the co-precipitation was achieved in various LPM-PEG mass ratios with changes in its morphology. In 10–50% PEG mass ratios, angular-shaped particles were formed, whereas in 65–90% PEG mass ratios, irregular-shaped particles were formed. X-ray diffraction (XRD) analysis of the co-precipitates revealed that the LPM retained amorphous structure, while, on the other hand, the PEG retained crystalline structure. Fourier transform infrared (FT-IR) spectra indicated carbonyl function group of LPM and ether function group of PEG appeared in the co-precipitates. Results of a dissolution test showed that the co-precipitates of LPM-PEG had higher dissolution rate compared to that of the raw material and processed LPM with ASES. Taken together, the co-precipitation of LPMPEG was achieved using ASES and higher in its dissolution rate.     

Micronization and characterization of squid lecithin/polyethylene glycol composite using particles from gas saturated solutions (PGSS) process

Lecithin was isolated from squid viscera residues after supercritical carbon dioxide (SC-CO₂) extraction at 25 MPa and 45 °C. The particle formation of squid lecithin with biodegradable polymer, polyethylene glycol (PEG) was performed by PGSS using SC-CO₂ in a thermostatted stirred vessel. By applying different temperatures (40 and 50 °C) and pressures (20–30 MPa), conditions were optimized. Two nozzles of different diameters (250 and 300 μm) were used for PGSS and the reaction time was 1 h. The average diameter of the particles obtained by PGSS at different conditions was about 0.74–1.62 μm. The lowest average size of lecithin particle with PEG was found by the highest SC-CO₂ density conditions with the stirring speed of 400 rpm and nozzle size of 250 μm. The inclusion of lecithin in PEG was quantified by HPLC. Acid value and peroxide value was measured after micronization of lecithin.