Poly Ethylene Glycols (PEG) and Micelles as Efficient Catalysts for the Oxidation of Xanthine Derivatives under Conventional and Non-Conventional Conditions

Oxidation of Xanthine alkaloid have been studied with various one and two electron oxidizing agents using PEGs and micelle forming surfactants. The reaction is too sluggish in solution phase, but moderately fast in presence of PEGs and micelles. However, the reactions are dramatically enhanced under microwave irradiations. Present protocol has several advantages, such as solvent-free conditions, during work-up, fast reaction times, high yields, eco-friendly operational and experimental simplicity, readily available additives as catalysts.

Study of Thermal,Phase Morphological and Mechanical Properties of Poly(L-lactide)-b-Poly(ethylene glycol)-b-Poly(L-lactide)/Poly(ethylene glycol)Blend Bioplastics

A poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide)(PLLA-PEG-PLLA)block copolymer has great potential for use as a flexible bioplastic.Highly flexible bioplastics are required for flexible packaging applications.In this work,a PEG was incorporated into block copolymer as a plasticizer by solvent casting.PLLA-PEG-PLLA/PEG blends with different blend ratios were prepared,and the plasticizing effect and miscibility of PEG in block copolymer were intensively investigated compared to PLLA/PEG blends.The results indicated that the PEG was an effective plasticizer for the block copolymer.The blending of PEG decreased glass-transition temperature and accelerated the crystallization of both the PLLA and PLLA-PEG-PLLA matrices.The PEG was completely miscible when blended with block copolymer and it improved thermal stability of the block copolymer matrix but not of the PLLA matrix.Film extensibility of PLLA-PEG-PLLA/PEG blends steadily increased as the PEG ratio increased.These non-toxic and highly flexible PLLA-PEG-PLLA/PEG bioplastics are promising candidates for several applications such as biomedical devices,tissue scaffolds and packaging materials.

Preparation and Thermo-Responsive Properties of Poly(Oligo(Ethylene Glycol)Methacrylate)Copolymers with Hydroxy-Terminated Side Chain

Thermo-responsive random copolymers,poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-(ethylene glycol)methyl ether methacrylate)(P(EO_(2)-co-EO_(4/5)))and poly(2-(2-methoxyethoxy)ethoxyethyl methacrylate-co-ethylene glycol methacrylate(P(EO2-co-EG4/5))are synthesized via atom transfer radical polymerization(ATRP).The successful synthesis and the narrow polydispersity index(PDI)of two copolymers are indicated by 1H nuclear magnetic resonance(1H-NMR)and gel permeation chromatography(GPC)analyses.The transition behaviors of polymers in the aqueous solution are demonstrated by changes in turbidity and particle sizes.The transition behavior of P(EO2-co-EG4/5)is found to be milder than that of P(EO2-co-EO4/5).Moreover,the presence of hydrogen bonds without thermo-responsive properties established by hydroxyl groups in the end-side chain of P(EO_(2)-co-EG_(4/5))hinders the dehydration at the transition temperature(TT).Attenuated total reflection Fourier transform infrared spectrometry(ATR-FTIR)analysis along with contact angle measurements reveals that both P(EO_(2)-co-EO_(4/5))and P(EO_(2)-co-EG_(4/5))films undergo phase transitions from hydrophilicity to hydrophobicity above TT.By examining the swelling and collapse behaviors of the polymer films during phase transitions,it can be concluded that the end hydroxyl groups may establish hydrogen bonds with neighboring ether groups within the films,which remain intact throughout the phase transition process due to their strong bonding interactions.This leads to an increase in steric hindrance within swollen films thereby impeding dehydration processes and inducing hysteresis during phase transitions.

Poly Ethylene Glycols as Efficient Media for the Synthesis of <i>β</i>-Nitro Styrenes from <i>α</i>, <i>β</i>-Unsaturated Carboxylic Acids and Metal Nitrates under Conventional and Non-Conventional Conditions

Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free conditions. The reactants were ground in a mortar with a pestle for about 30 minutes. The aromatic acids underwent nitro decarboxylation and afforded β-nitro styrene derivatives in very good yield while α, β-unsaturated aliphatic carboxylic acids gave corresponding nitro derivatives. Addition of PEG accelerated rate of the reaction enormously. Reaction times substantially decreased from several hours to few minutes followed by highly significant increase in the product yield. Among the several PEGs PEG-300 has been found to be much more effective than other PEGs.

Controlled delivery of ibuprofen from poly(vinyl alcohol)-poly(ethylene glycol) interpenetrating polymeric network hydrogels

Hydrogels composed of poly(vinyl alcohol)(PVA) and poly(ethylene glycol)(PEG) were synthesized using glutaraldehyde as crosslinker and investigated for controlled delivery of the common anti-inflammatory drug, ibuprofen(IBF). To regulate the drug delivery, solid inclusion complexes(ICs) of IBF in β–cyclodextrin(β–CD) were prepared and added to the hydrogels. The ICs were prepared by the microwave irradiation method, which is more environmentally benign. The formation of IC was confirmed by various analytical techniques and the synthesized hydrogels were also characterized. Controlled release of drug was achieved from the hydrogels containing the ICs in comparison to the rapid release from hydrogels containing free IBF.The preliminary kinetic analysis emphasized the crucial role of β–CD in the drug release process that influences the polymer relaxation, thereby leading to prolonged release. The cytotoxicity assay validated the hydrogels as non-toxic in nature and hence can be utilized for controlled delivery of IBF.

THE STRUCTURE AND PROPERTIES OF CHITOSAN/POLYETHYLENE GLYCOL/SILICA TERNARY HYBRID ORGANIC-INORGANIC FILMS

The ternary hybrid films consisting of chitosan(CS),polyethylene glycol(PEG)and nano-sized silica which was surface-modified by amino groups(RNSA)were prepared.The structures of the blend membranes were characterized by attenuation total reflection-infrared spectroscopy(ATR-IR),X-ray diffraction(XRD),optical microscopy(OM)and differential scanning calorimetry(DSC).The results showed that the addition of silica affected not only the distribution and crystallinity of PEG on the sample surface,but also the ...

SURFACE MODIFICATION OF BLEND FILMS COMPOSED OF SILK FIBROIN AND POLY(ETHYLENE GLYCOL) MACROMER AND THEIR IN VITRO ANTITHROMBOGENICITY

In order to improve the blood compatibility of silk fibroin (SF), poly(ethylene glycol) macromer (PEGM) in different amounts was added to the SF film to incorporate C=C group into the surface of blend films which were then modified by SO2 gas plasma treatment. ATR-FITR and XPS were used to analyze the chemical change which had occurred on the film’s surface. When the content of sulfur on the surface of blend films surpasses 1.59%, the antithrombogenicity of plasma treated films increases remarkably due to surface sulfonation. This result implies that SF with blend of PEGM after SO2 plasma treatment have potential use for making blood-contacting biomaterials.

Selective swelling of polysulfone/poly(ethylene glycol) block copolymer towards fouling-resistant ultrafiltration membranes

Fouling resistance of ultrafiltration(UF) membranes is critical for their long-term usages in terms of stable performance, so convenient approaches to prepare fouling-resistant membranes are always anticipated. Herein, we demonstrate the facile fabrication of antifouling polysulfone-block-poly(ethylene glycol)(PSF-b-PEG, SFEG)composite membranes. SFEG layer was coated onto macroporous supports and cavitated by immerging them in acetone/n-propanol following the mechanism of selective swelling induced pore generation. Thus-produced SFEG membranes possessed high permeance and excellent mechanical strength. Meanwhile, the structures and separation performances of the SFEG layers can be continuously tuned through simply changing swelling durations. More importantly, the hydrophilic PEG chains were spontaneously enriched onto the pore walls through swelling treatment, endowing intrinsic antifouling property to the SFEG membranes. Bovine serum albumin(BSA)/humic acid(HA) fouling tests proved the prominent fouling resistance of SFEG membranes, and the fouling resistance is expected to be long-standing because of the firm connection between PEG chains and PSF matrix by covalent bonding.

Poly(L-lactide)-Poly(ethylene glycol) Multiblock Copolymers: Synthesis and Properties

Poly (L-lactide)-poly(ethylene glycol) multiblock copolymers with predetermined block lengths were synthesized by polycondensation of PLA diols and PEG diacids. These copolymers presented special properties, such as better miscibility between the two components, low crystallinity and better hydrophilicity, which can be modulated by adjusting the block lengths of the two components.

Y-shaped block copolymers of poly(ethylene glycol) and poly(N-isopropylacrylamide) synthesized by ATRP

新奇的塑造 Y 的块共聚物 poly (乙烯乙二醇) 并且 poly (N-isopropylacrylamide ) ， PEG-b-(PNIPAM )2, 成功地通过原子转移激进分子聚合(ATRP ) 被综合。一个 difunctional 宏开始者被 2,2-dichloroacetyl 氯化物的酯化作用准备与 poly (乙烯乙二醇) 单音的甲基醚(木钉) 。共聚物在 30 ° 经由 N-isopropylacrylamide (NIPAM ) 的 ATRP 被获得；有 CuCl/Me 6 TREN 作为一个催化剂系统和 DMF/H 2 O (v/v = 3:1 ) 混合是溶剂。产生共聚物被胶化浸透层析(GPC ) 和 1 H NMR。这些块共聚物显示出可控制的分子的重量和狭窄的分子的重量分布(PDI <； 1.15 ) 。他们在水的答案的阶段转变温度和相应热含量变化被微分扫描热量测定(DSC ) 测量。作为结果，木钉 45-b-(PNIPAM55)2 的阶段转变温度比然而， PNIPAM，相应热含量变化是低得多的高，显示阶段上的分子的作文和建筑学转移的宏的重要影响。

PREPARATION OF HIGH DENSITY POLYETHYLENE/POLYETHYLENE-BLOCK-POLY(ETHYLENE GLYCOL)COPOLYMER BLEND POROUS MEMBRANES VIA THERMALLY INDUCED PHASE SEPARATION PROCESS AND THEIR PROPERTIES

高密度聚乙烯(HDPE )/polyethylene-block-poly (乙烯乙二醇)(PE-b-PEG ) 混合多孔的膜经由热地导致的阶段分离(尖端) 被准备过程使用 diphenyl 醚(DPE ) 同样稀释。HDPE/PE-b-PEG/DPE 系统的阶段图被光显微镜学和微分扫描热量测定(DSC ) 决定。由改变 PE-b-PEG 的内容，形态学和膜的水晶的结构上的 PE-b-PEG 共聚物的效果被扫描电子显微镜学(SEM ) 和宽角度 X 光检查衍射(WAXD ) 学习。整个膜和表面层的化学作文被基本分析描绘， Fourier 变换红外线的稀释光谱学的全部的思考(FTIR-ATR ) 和 X 光检查光电子光谱学(XPS ) 。水接触角度，静态的蛋白质吸附和水流动实验被用来评估 hydrophilicity， antifouling 和膜的水浸透性质。PE-b-PEG 的增加增加了获得的混合膜的毛孔尺寸，这被发现。在 PE-b-PEG 内容的调查范围， PEG 块不能在膜矩阵聚集进显然分开的领域。更重要地， PE-b-PEG 不能仅仅在膜矩阵稳定地被保留在膜形成期间，而且在膜表面层充实。PE-b-PEG 的如此的稳定性和表面丰富赋予了混合膜以改进 hydrophilicity，蛋白质吸收抵抗和水浸透性质，它将对为水处理申请的 HDPE 膜实质地有益。关键词高密度聚乙烯 - Polyethylene-block-poly (乙烯乙二醇) 共聚物 - 混合多孔的膜 - 热地导致的阶段分离这个工作被 863 节目(号码 2006AA03Z233 ) 和中国的 973 节目(号码 2009CB623402 ) 财政上支持。

Synthesis and Hydrophilic Performance of Poly(Lactic Acid)-Poly(Ethylene Glycol) Block Copolymers

Lactide was synthesized using lactic acid and stannous octoate as raw material and catalyst, respectively. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was prepared by lactide and poly (ethylene glycol) (PEG) via ring-opening polymerization. The most appropriate technological conditions of synthesis of lactide were researched in the paper. The copolymers were measured by Infrared spectroscopy (IR) and 1H nuclear magnetic resonance (1H NMR). The results proved that the lactide and PLA-PEG were synthesized successfully. Hydrophilic performance of the copolymer was measured by a water contact angle tester after prepared into a flat membrane. The water contact angle changed from 81.5? to 71.6?, which proved that the hydrophily of PLA-PEG was better than PLA.

RING-OPENING COPOLYMERIZATION OF DL-LACTIDE AND POLY(ETHYLENE GLYCOL) INITIATED BY LANTHANUM ACETATE AND APPLICATION OF THE COPOLYMER AS MATRIX OF MICROSPHERES CONTAINING VIBRIO CHOLERA ANTIGENS

Poly-dl -lactide-poly(ethylene glycol ) (PELA) triblock copolymers were synthesized withlanthanum acetate as the initiator. PELA microspheres with entrapped Vibrio Cholera antigen and outermembrane protein (OMP) were prepared by a double emulsion W/O/W based on solvent extraction methods.The obtained microspheres showed smooth and spherical surface and their size varied between 0.5 and 5.0μm, which are suitable for oral targeting delivery system. The distribution tests in rabbits and mice throughscanning electronic micrography and fluorescence microscope indicated that microspheres have successfullyreached the immunization-related tissues, such as the liver, spleen and intestinal peyer’s patches, followingoral administration. The PELA microspheres were also evaluated as an efficient antigen delivery system byenhancing a higher protective ratio against live Vibrios Cholera.

Surface Modification of Polycarbonate Urethane by Covalent Linkage of Heparin with a PEG Spacer

Heparin was grafted onto polycarbonate urethane (PCU) surface via a three-step procedure utilizing α, ωdiamino-poly(ethylene glycol) (APEG, M n =2 000) as a spacer. In the first step, isocyanate functional groups were introduced onto PCU surface by the treatment of hexamethylene diisocyanate (HDI) in the presence of di-n-butyltin dilaurate (DBTDL) as a catalyst. In the second step, APEG was linked to the PCU surface to obtain the APEG conjugated PCU surface (PCU-APEG). In the third step, heparin was covalently coupled with PCU-APEG in the presence of N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylamidopropyl) carbodiimide (EDAC). The amount of heparin (1.639 μg/cm 2 ) covalently immobilized on the PCU-APEG surface was determined by the toluidine blue method. The modified surface was characterized by water contact angle, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The hemocompatibility was preliminarily studied by platelet adhesion test. The results indicated that heparin was successfully grafted onto the PCU surface, and meanwhile the hydrophilicity and hemocompatibility of the modified PCU surface were improved significantly compared with the blank PCU surface.

Aggregation of Sodium Dodecyl Sulfonate in Poly-ethylene Glycol Aqueous Solutions Studied by Two-dimensional Nuclear Overhauser Enhancement Spectroscopy

Two-dimensional nuclear overhauser enhancement (2D NOESY)measurements show that sodium dodecyl sulfonate SDSN molecules co-aggregate with poly-ethylene glycol PEG in their aqueous solution at a concentration range of SDSN between the so-called co-aggregation concentration (cac) and the. Normal critical micellar concentration (cmc). SDSN micelles are formed when the cmc of SDSN is reached with PEG uniformly distributed in the interior.

The Synthesis of Poly(ethylene oxide)-Block-Polybutylacrylate

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POLYMERIZATION OF ETHYLENE METHYL PHOSPHATE IN THE PRESENCE OF SODIUM POLY(ETHYLENE GLYCOL)ATE

Poly（ethylene methyl phosphate）-poly（ethylene glycol）-poly（ethylene methyl phosphate） triblockcopolymers carrying hydroxyl group at both chain ends were synthesized with sodium poly（ethyleneglycol）ate as initiator. The effects of the factors such as solvent, amount of the initiator and reaction timewere investigated. The copolymers were characterized by IR, 1H-NMR, 1H{31P}-NMR, 13C-NMR, 31P{1H}-NMR, and DSC. High molecular weight of the copolymer and high yield of the polymerization were achievedwithin 3 min at 25℃. The polymerization process was studied by 31P{1H}-NMR and transesterification wasfound during longer polymerization time.

KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION OF POLY (ETHYLENE TEREPHTHALATE) MODIFIED BY POLY (ETHYLENE GLYCOL)

The non-isothermal crystallization kinetics of poly（ethylene terephthalate） （PET） modified by poly （ethlene glycol） （PEG） were determined by DSC. The dual linear regression method was used to evaluate the relationship between the reciprocal of t 1/2 （ the half life of crystallization） and the appropriate temperature variable. The parameters such as the activation energy （Ed） for transport, the equilibrium melting temperature （Tm0）,the nucleation parameter （ψ）,themaximum crystallization temperature (Te, max), and the kinetic crystallizability （G） for the copolyesters were obtained. The influence of the PEG content in PET chains on the parameters characterizing crystallization kinetics and crystallization thermodynamics was discussed.

SYNTHESIS OF NOVEL BLOCK COPOLYMERS OF POLY(3-HYDROXYBUTYRIC ACID)WITH POLY(ETHYLENE GLYCOL)THROUGH ANIONIC POLYMERISATION

A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-openingpolymerization of β-butyrolactone (β-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which wereprepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M_n=2000, 4000 and6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterizedby IR,~1H-NMR and GPC.

POLYCAPROLACTONE-POLY (ETHYLENE GLYCOL) BLOCK COPOLYMER Ⅲ DRUG RELEASE BEHAVIOR

The drug release behavior of degradable polymer--polycaprolactone-poly (ethyleneglycol)block copolymer(PCE) in vitro was investigated by using 5-Fluoro-uracil (5-Fu) asa model drug under a condition of pH 7. 4 at 37C. It is found that the release rate of 5-Fufrom PCE increased with increasing polyether content of the copolymer. The results showthat the increasing polyether content of the copolymer caused increasing hydrophilicity anddecreasing crystallinity of the PCE copolymer. Thus, the drug release behavior and thedegradable property of the PCE can be controlled by adjusting the composition of thecopolymer.