Self-assembly and drug release control of dual-responsive copolymers based on oligo(ethylene glycol)methyl ether methacrylate and spiropyran

Iranian Polymer Journal - To compare the synthesis and drug release of random and block copolymers, random and block copolymerizations of oligo(ethylene glycol)methyl ether methacrylate (OEGMA) and...     

Synthesis and characterization of amphiphilic block copolymers from poly(ethylene glycol)methyl ether and 4-methyl-?-caprolactone or 4-phenyl-?-caprolactone

MPEG-b-PMCL and MPEG-b-PBCL diblock copolymers were synthesized by ring-opening polymerization of 4-methyl-?-caprolactone (MCL) or 4-phenyl-?-caprolactone (BCL) using monomethoxy poly(ethylene glycol) (MPEG, M_n = 550 or 2000 g mol⁻¹) as the macroinitiator and SnOct₂ as the catalyst. These copolymers were characterized by differential scanning calorimetry (DSC), ¹H NMR, ¹³C NMR, and gel permeation chromatography. The thermal properties (T_g and T_m) of the diblock copolymers depend on the composition of polymers. When larger amount of MCL or BCL was incorporated into the macromolecular backbone there was an increase in T_g. Their micellar characteristics in the aqueous phase were investigated by fluorescence spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). The block copolymers formed micelles in the aqueous phase with critical micelle concentrations (CMCs) in the range of 0.5-2.9 mg L⁻¹, depending on the composition of polymers. The lengths of hydrophilic segment influence the shape of micelle. The mean hydrodynamic diameters of micelles from DLS were in the range of 70-140 nm. The drug entrapment efficiency and the drug-loading content of micelles depending on the composition of block polymers were described.     

杂多酸盐催化乙二醇合成乙二醇乙醚和乙二醇双乙醚的研究

以磷钨酸、硅钨酸和磷钼酸及硝酸银、硝酸铁、硝酸铯和碳酸铯为原料,通过共沉淀法制备了系列杂多酸盐催化剂,通过X射线衍射仪(XRD)、电子能谱(EDS)、热重/差热分析仪(TG)对催化剂的晶型结构、表面元素及热重性质进行了表征。结果表明,磷钨酸银铯和磷钨酸银具有Keggin型磷钨酸结构,表面元素分布均匀,煅烧温度在20～220℃时会失去结合水,300～450℃时会失去结晶水和结构水,900℃以上则会分解。通过催化乙二醇和乙醇合成乙二醇乙醚和乙二醇双乙醚的反应考察杂多酸及杂多酸盐催化性能。考察了阳离子种类、取代度和不同煅烧温度对杂多酸盐催化性能的影响,结果表明,磷钨酸及其盐系列催化剂效果最好。通过考察阳离子种类和磷钨酸氢离子的取代度,结果表明,Cs_(0.66)Ag_(0.33)H_2PW_(12)O_(40)催化效果最好。在该催化剂存在下,n_(乙二醇)∶n_(乙醇)为1∶4,反应时间4 h,反应温度200℃,乙二醇转化率为98.16%,乙二醇乙醚选择性为49.25%,乙二醇双乙醚选择性为48.59%,乙二醇醚的总产率为96.04%。     

丙烯酸甲氧基乙酯的合成方法

丙烯酸甲氧基乙酯是一种重要的化工中间体,属于丙烯酸酯类化合物.丙烯酸酯类化合物由于其具有活性高、稀释能力强、低毒、低刺激性等特点,已被广泛的用于涂料、粘合剂、油墨等化工领域.     

杂多酸盐催化乙二醇合成乙二醇乙醚和乙二醇双乙醚的研究

以磷钨酸、硅钨酸和磷钼酸及硝酸银、硝酸铁、硝酸铯和碳酸铯为原料,通过共沉淀法制备了系列杂多酸盐催化剂,通过X射线衍射仪(XRD)、电子能谱(EDS)、热重/差热分析仪(TG)对催化剂的晶型结构、表面元素及热重性质进行了表征。结果表明,磷钨酸银铯和磷钨酸银具有Keggin型磷钨酸结构,表面元素分布均匀,煅烧温度在20～220℃时会失去结合水,300～450℃时会失去结晶水和结构水,900℃以上则会分解。通过催化乙二醇和乙醇合成乙二醇乙醚和乙二醇双乙醚的反应考察杂多酸及杂多酸盐催化性能。考察了阳离子种类、取代度和不同煅烧温度对杂多酸盐催化性能的影响,结果表明,磷钨酸及其盐系列催化剂效果最好。通过考察阳离子种类和磷钨酸氢离子的取代度,结果表明,Cs_(0.66)Ag_(0.33)H_2PW_(12)O_(40)催化效果最好。在该催化剂存在下,n_(乙二醇)∶n_(乙醇)为1∶4,反应时间4 h,反应温度200℃,乙二醇转化率为98.16%,乙二醇乙醚选择性为49.25%,乙二醇双乙醚选择性为48.59%,乙二醇醚的总产率为96.04%。     

乙二醇单叔丁醚与乙二醇二叔丁醚的分离

在实验测定乙二醇单叔丁醚(TMBE)与乙二醇二叔丁醚(TDBE)相平衡数据的基础上,回归得到了Wilson方程的相互作用参数Λ12和Λ21,并利用回归参数的Wilson方程预测了TMBE和TDBE共沸组成随压力降低,TMBE的摩尔分数降低。根据此特性,文中设计了利用差压精馏分离TMBE和TDBE的流程,并在Pro/II流程模拟软件上,建立了差压精馏分离TMBE和TDBE的模型并进行了模拟计算。模拟结果表明:利用差压精馏可分别获得纯度(摩尔分数)大于99%以上的TMBE和TDBE。     

Synthesis and characterization of polyester-imides from imidodicarboxylic acid monomers and ethylene glycol

Two monoimidodicarboxylic acids and four diimidodicarboxylic acids were synthesized from trimellitic anhydride and amino compounds, viz., glycine, p-aminobenzoic acid, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl methane, and 4,4'-diaminodiphenyl sulfide, and characterized by IR and ¹H-NMR spectroscopies and melting-point determination. These functional monomers were condensed in N-methyl-2-pyrrolidone solvent with ethylene glycol by a transesterification reaction to obtain the novel polyester-imides with backbones of alternate imide-ester linkages or imide-imide-ester-ester linkages with ? SO₂? , ? O? , ? CH₂? , or ? S? S? bridges in between. All the polymers were characterized by IR and ¹H-NMR spectroscopies, X-ray diffraction, solution viscosity, solubility and solubility parameters, and differential thermal analysis. Most of the polymers possess amorphous structure and fairly high decomposition temperatures (450–485°C). These polymers having solubility parameters in the range δ 11.44–11.85, as determined by the group contribution technique, are soluble at room temperatures in aprotic polar solvents. © 1993 John Wiley & Sons, Inc.     

Synthesis and characterization of ABA-triblock copolymers with poly(ethylene glycol) segments and LC-segments

This paper describes the synthesis of ABA-triblock copolymers with poly(ethylene glycol) A-blocks and a liquid crystalline polyester B-block. Three block copolymer series are presented with different block length of A- and B-blocks. The block copolymers show thermotropic liquid crystalline behavior up to a content of poly(ethylene glycol) segments of 50 wt%. Depending on their composition and chain length, the block copolymers are microphase separated or non-microphase separated. In the microphase separated block copolymers the poly(ethylene glycol) segments are able to crystallize. The degree of crystallinity and the spherulite diameter is strongly influenced by the length of the poly(ethylene glycol) segment itself as well as by the length of the incorporated polyester segment. Received: 19 December 1997/Revised version: 22 December 1997/Accepted: 22 December 1997     

Synthesis and characterization of cleavable surfactants derived from poly(ethylene glycol) monomethyl ether

A series of noncyclic acetal-linked cleavable surfactants were simply prepared by condensation of aldehydes with poly(ethylene glycol) monomethyl ethers. All of the products were characterized by¹H nuclear magnetic resonance. Their hydrophile-lipophile balance, surface tension, cloud point, critical micelle concentration, and foam height were determined. Hydrolysis kinetic studies, followed by gas chromatography, showed that they had higher hydrolytic reactivity in acidic solution than cyclic acetal-linked cleavable surfactants.     

Styrene/phosphonic acid copolymers: Synthesis and thermal,mechanical, and electrochemical characterization

In this study, a series of poly(styrene‐co‐vinyl phosphonic acid) [P(S‐co‐VPA)] copolymers were synthesized by the free‐radical copolymerization of styrene and vinyl dimethyl phosphonate followed by alkaline hydrolysis. The P(S‐co‐VPA) copolymers were characterized by size exclusion chromatography (gel permeation chromatography), Fourier transform infrared vibrational spectroscopy, proton nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and electrochemical impedance spectroscopy. Despite the difference between the copolymerization ratios of styrene and vinyl dimethyl phosphonate, the resulting copolymers presented single glass transitions at temperatures that depended on the acidic group amount. The glass transition shifted to a higher temperature and became broader as the amount of phosphonic acid increased. The storage modulus at temperatures higher than the glass transition also increased with increasing acidic groups because of intramolecular and intermolecular interactions. All of the acid copolymers were thermally stable to at least 300°C. A high oxidative stability was found for 3 : 1 P(S‐co‐VPA), which also presented conductivity values on the order of 10⁻⁶ Ω⁻¹ cm⁻¹ at room temperature. The 1 : 1 P(S‐co‐VPA) membrane presented Arrhenius‐type behavior at temperatures from 30 to 80°C and conductivity on the order of 10⁻⁵ Ω⁻¹ cm⁻¹. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of amphiphilic polyisobutylene/poly(ethylene glycol) di- and triblock copolymers

Summary Di- and triblock copolymers of polyisobutylene PIB and poly(ethylene glycol) PEG have been prepared and characterized. The syntheses involved the capping with tolylene 2,4-diisocyanate TDI various molecular weight -phenyl--(p-phenol) polyisobutylenes C₆H₅-PIB-C₆H₄OH and ,-di-(p-phenol)polyisobutylenes HOC₆H₄-PIB-C₆H₄OH, or commercially available mono- and di-hydroxyl-terminated PEGs. In this manner a series of PIB-b-PEG diblock copolymers, and PEG-b-PIB-b-PEG and PIB-b-PEG-b-PIB triblock copolymers have been obtained. The complete removal of the prepolymers from these amphiphilic sequential copolymers by conventional solvent extraction techniques could not be achieved because of the very high emulsifying action of the latters. In contrast, satisfactory separation was obtained by column chromatography using mixed (polar/nonpolar) eluents. The blocking efficiencies and composition of the block copolymers have been determined.Part XL V of the Series on New Telechelic Polymers and Sequential Copolymers by Polyfunctional Initiator-Transfer Agents (Inifers).     

Synthesis and characterization of block copolymers from D,L-lactide and poly(tetramethylene ether glycol)

The copolymer from D ,L -lactide and poly(tetramethyene ether glycol) (PTMG) was prepared in bulk with an isotributyl aluminum–water–phosphoric acid complex catalyst as the initiator and characterized by H-NMR, GPC, and DSC. The effects of the temperature and the amount of PTMG on the polymerization rate and the molecular weight of copolymers were studied. The behavior of the degradation and delivery rate of Levonorgestrel microspheres in vitro was observed. The results show that the degradation and the delivery rate can be controlled by adjusting the molar rate of hydrophilic and hydrophobic segments of the copolymer © 1995 John Wiley & Sons, Inc.     

Synthesis and characterization of amphiphilic graft copolymers with poly(ethylene glycol) and cholesterol side chains

Amphiphilic graft copolymers comprising monomeric units of methoxy poly(ethylene glycol) (mPEG)-acrylate, 2-hydroxyethyl methacrylate (HEMA)–cholesterol conjugates and HEMA were synthesized and their properties characterized. The value of the critical micelle concentration (CMC) for these copolymers is linearly proportional to the ratio of the number of mPEG–acrylates to that of the HEMA–cholesterol conjugates per macromolecule (N_PEG/N_c), which is the most important parameter which influences the formation of polymeric micelles. The latter show excellent colloidal stability and their sizes decrease with increasing CMC. Based on the quenching of pyrene fluorescence, the relatively high levels of the loading capacity of pyrene are attributed to the elevated hydrophobicity of the micelle core. The loading capacity of pyrene decreases with increasing CMC. The weight-average partition coefficient for pyrene in polymeric micelles increases with increasing polymer concentration because more micelles are available for accommodating pyrene. Copyright © 2004 Society of Chemical Industry     

Chemosynthesis and characterization of fully biomass‐based copolymers of ethylene glycol, 2,5‐furandicarboxylic acid,and succinic acid

Poly(ethylene 2,5‐furandicarboxylate‐co‐ethylene succinate) (PEFS) copolymers of 2,5‐furandicarboxylic acid (FDCA) and succinic acid with 11.98–91.32 mol % FDCA composition were synthesized via melt polycondensation in the presence of ethylene glycol using tetrabutyl titanate as a catalyst. PEFSs' molecular weight, thermal properties, and molar composition were determined by Fourier transform infrared spectroscopy, gel permeation chromatography, intrinsic viscosity, ¹H NMR, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and wide‐angle X‐ray diffraction (WAXD) measurements. From experimental conditions, we obtained random copolymers with number‐average molecular weights exceeding 25,600, determined by GPC and ¹H NMR analyses. DSC analysis revealed that PEFS copolymers' melting temperatures differed depending on EF units' percentage. TGA studies confirmed that all PEFS copolymers' thermal stability exceeded 300°C. From WAXD analysis, it is observed that the PEFS copolymer crystal structure was similar to that of PES when EF unit was 11.98 mol % and to that of PEF when EF units were 74.35 and 91.32 mol %. These results benefit this novel biodegradable copolymer to be used as a potential biomaterial. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1415‐1420, 2013     

Synthesis and characterization of amine‐functionalized amphiphilic block copolymers based on poly(ethylene glycol) and poly(caprolactone)

A series of amine‐functionalized block copolymers, poly(caprolactone)‐block‐poly(ethylene glycol) (PCL‐b‐PEG), were synthesized by ring‐opening bulk polymerization (ROP) of ε‐caprolactone (ε‐CL) initiated through the hydroxyl end of the amino poly(ethylene glycol) (PEG) used as a macroinitiator in the presence of stannous 2‐ethylhexonoate [Sn(Oct)₂]. The polymerization and end functionality of the polymer were studied by different physicochemical techniques (¹H NMR, Fourier transform infrared and X‐ray photoelectron spectroscopy, gel permeation chromatography and thermogravimetric analysis). Thermal, crystalline and mechanical properties of the polymer were thoroughly analyzed using differential scanning calorimetry, wide‐angle X‐ray diffractometry and tensile testing, respectively. The results showed a linear improvement in crystallinity and mechanical properties of the polymer with the content of PEG. Thus the synthesized functional polymers can be used as excellent biomaterials for the delivery of polyanions, as well as macroinitiators for the synthesis of A–B–C‐type block copolymers. Copyright © 2006 Society of Chemical Industry     

Synthesis and characterization of star-shaped poly(d,l-lactide)-block-poly(ethylene glycol) copolymers

Star-shaped hydroxy-terminated poly(d,l-lactide) (s-PDLLA), with arms of different lengths, were obtained by ring-opening polymerization (ROP) of d,l-lactide (LA) initiated by varied contents of pentaerythritol (PETH) in the presence of stannous octoate (Sn(Oct)₂), and were condensed with carboxyl-terminated poly(ethylene glycol) methyl ether (CT-mPEG, M _n = 850 and 2,000) to afford four-arm star-shaped poly(d,l-lactide)-block-poly(ethylene glycol) copolymer (s-PDLLA-b-PEG). The polymers, including s-PDLLA, CT-mPEG, and s-PDLLA-b-PEG, were characterized and confirmed by ¹H-NMR and ¹³C-NMR spectroscopy, fourier transform infrared spectroscopy (FT-IR), and gel permeation chromatography (GPC).     

Synthesis and characterization of copolymers of bromoacrylated methyl oleate

In this study, methyl oleate was bromoacrylated in the presence of N‐bromosuccinimide and acrylic acid in one step. Homopolymers and copolymers of bromoacrylated methyl oleate (BAMO) were synthesized by free radical bulk polymerization and photopolymerization techniques. Azobisisobutyronitrile (AIBN) and 2,2‐dimethoxy‐2‐phenyl‐acetophenone were used as initiators. The new monomer BAMO was characterized by FTIR, GC‐MS, ¹H, and ¹³C‐NMR spectroscopy. Styrene (STY), methylmethacrylate (MMA), and vinyl acetate (VA) were used for copolymerization. The polymers synthesized were characterized by FTIR, ¹H‐NMR, ¹³C‐NMR, and differential scanning calorimetry (DSC). Molecular weight and polydispersities of the copolymers were determined by GPC analysis. Ten different feed ratios of the monomers STY and BAMO were used for the calculation of reactivity ratios. The reactivity ratios were determined by the Fineman–Ross and Kelen–Tudos methods using ¹H‐NMR spectroscopic data. The reactivity ratios were found to be r_sty = 0.891 (Fineman–Ross method), 0.859 (Kelen–Tudos method); r_bamo = 0.671 (Fineman–Ross method), 0.524 (Kelen–Tudos method). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2475–2488, 2004     

硫酸氢钠催化合成乙二醇单甲醚乙酸酯

将硫酸氢钠作为由乙二醇单甲醚和乙酸酯化合成乙二醇单甲醚乙酸酯的催化剂。研究了反应的影响因素和催化剂重复使用性能。当n(乙二醇单甲醚)∶n(乙酸)∶n(硫酸氢钠)＝1∶1.75∶0.003 62、苯为带水剂、回流分水60 min时,酯收率达90.0%。     

新戊二醇改性PET的合成与表征

以对苯二甲酸为主要原料，通过加入2%～15%（摩尔）新戊二醇，合成了一系列不同二醇配比的共聚酯，用示差扫描量热方法研究了该体系的热性能。结果表明，共聚酯的熔点和结晶度均随新戊二醇的加入而降低。