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In this research, diglycidyl ethers of bisphenol-A (BADGE) and polyethylene glycol (PEGDGE) were binarily cured with a mixture of diamine curing agents including isophorone diamine and polyethylene glycol diamine (PEGDA) in the absence/presence of aminated graphene oxide nanoplatelets (AGNPs, 0.5 wt.%). Four molar ratios of diglycidyl ethers and curing agents were used stoichiometrically in isothermal curing systems. The films prepared from the epoxy networks were entirely strong and pliable. All epoxy thermosets were evaluated using field emission-scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and diffuse reflectance-ultraviolet/visible spectroscopy (DR-UV/vis). The absorption coefficients of the epoxy and AGNPs-loaded epoxy materials decreased with increasing the molar ratio of PEGDGE resin and polyethylene glycol diamine curing agent. According to dynamic mechanical analysis no phase heterogeneity occurred in the structure of the prepared thermostats. When the thermoset materials were loaded by AGNPs filler, the peaks associated with alpha relaxations shifted to higher temperatures. Moreover, thermogravimetric analysis demonstrated that the thermal stability of the prepared epoxy thermosets slightly increased after the addition of the nanoplatelets. In addition, the thermal resistance of the prepared thermosets decreased to some extent by increasing the participation rate of monomers containing polyoxyethylene. Graphical Abstract [ABSTRACT FROM AUTHOR]

In order to analyze the degreasing effect of a demulsifiable polyoxyethylene and polyoxypropylene alkyl ether sample on the steel plates, the conductivity, acidity, particle size, infrared spectrum, ultraviolet spectrum, nuclear magnetic spectrum, degreasing rate and corrosion resistance of the demulsifiable polyoxyethylene and polyoxypropylene alkyl ether sample were analyzed in detail. Results showed that the main component of the sample was non - anionic and non - cationic surfactant. Polyoxyethylene and propylene segments contained in polymer had similar structure and the properties with polyoxyethylene castor oil and OP - 10. Besides, it was an emulsifier with excellent surface activity, which could be applied to large - area degreasing surface treatment of steel plate.

In this work, a cellulose nanofibrils (CNFs)/few-layer graphene (FLG) hybrid is mechanically stripped from bamboo pulp and expanded graphene (EG) using a grinder. This strategy is scalable and environmentally friendly for high-efficiency exfoliation and dispersion of graphene in an aqueous medium. The in situ-generated CNFs play a key role in this process, acting as a "green" dispersant. Next, the obtained CNFs-FLG is used as a functional filler in a polyoxyethylene (PEO) matrix. When the composition of CNFs-FLG is 50 wt.%, the resultant PEO/CNFs-FLG nanocomposite film exhibits a Young's modulus of 1.8 GPa and a tensile strength of 25.7 MPa, showing 480% and 260% enhancement as compared to those of the pure PEO film, respectively. Remarkably, the incorporation of CNFs-FLG also provides the nanocomposite films with a stunning electrical conductivity (72.6 S/m). These attractive features make PEO/CNFs-FLG nanocomposite films a promising candidate for future electronic devices. [ABSTRACT FROM AUTHOR]

Ordered core(PEO)-shell(PHB) microfibers were prepared by coaxial electrostatic spinning technology and high-speed rotating receiving roller with polyoxyethylene (PEO)/chloroform solvent as core spinning solution and poly(β-hydroxybutyrate) (PHB)/chloroform solvent as shell spinning solution. The surface morphology, core-shell structure, thermal properties, crystallization properties and mechanical properties of core(PEO)-shell(PHB) microfiber film were characterized and analyzed by SEM, TEM, DSC, TGA, XRD and DMA. The results show that PEO/PHB microfiber has remarkable core-shell structure; fiber arranges in the same direction and the average diameter are 0.57-1.27 μm; the crystal structure of core(PEO)-shell(PHB) microfiber includes α-type crystal of PHB and monoclinic crystal of PEO; when the spinning voltage is increased, the diameter of the fiber decreases, and the crystallinity increases first and then decreases; the fiber diameter increases with the increase of injection speed, and the crystallinity first increases and then decreases; with the increase of the collection distance, the fiber diameter first decreases and then increases, and the crystallinity first increases and then decreases. By changing the single spinning condition, the corresponding fiber films with the spinning voltage of 18 kV, the push velocity of 0.07 mm/min and the collection distance of 8 cm all have high mechanical properties. Compared with pure PHB fiber and PEO fiber, the thermal stability of each component in ordered core(PEO)-shell(PHB) microfiber is improved.

The use of 3D printing is becoming more and more popular, and new applications in extrusion and photopolymerization are being discovered every day. Due to the unidirectional action of the materials used, it is necessary to develop polyfunctional composites that provide a complex of extrusion and photopolymerization processes for 3D printing technology. The current problem of 3D printing application is the availability of ineffective composite materials with deteriorated mechanical and damping properties, which makes it difficult to use existing composite materials for application in 3D printing technologies. Therefore, the aim of this study was to create a biodegradable composite material based on polylactic acid and poly(3‐hydroxybutyrate) reinforced with cellulose fibrils and plasticized with polyoxyethylene for possible application in extrusion, using the example of Maestro 3D printer. The study looked at mechanical, dynamic and thermal indicators. Except for the mechanical ones, all of the indicators tested out to be quite good. Thus, composite PLA: PHB (3:7) + 10% CFs demonstrated the highest glass transition temperature of 57°C. A 75% weight loss occurred at 373.58°C. In future, it is necessary to investigate alternative types of characteristics, modify the material's composition, or use it in applications where they are not critical. The scientific novelty of the work is the creation of a biodegradable composite material to study the properties of the composite material by extrusion for the purpose of application in 3D printing technologies. [ABSTRACT FROM AUTHOR]

Fatty alcohol‐polysorbate 60‐water ternary systems were used as models to represent the continuous phases of the respective semisolid oil‐in‐water emulsions for topical delivery of cosmetic and medicinal agents. The influence of batch variation of polysorbate 60 and fatty alcohol on structure and consistency of these systems was investigated using microscopy, rheology, differential scanning calorimetry and X‐ray scattering techniques. The polysorbate 60 : cetostearyl alcohol mixed emulsifying wax showed swelling in water, that is, the lamellar repeat distance continually augmented from 93 to 125 Å with water percentage 20–90%. Cetostearyl alcohol ternary systems were thicker than cetyl alcohol ones independently of polysorbate 60 batches used. All the ternary systems showed an initial increase in consistency over the first 2 weeks of storage, which was followed by slight changes in consistency (cetostearyl alcohol systems) due to the re‐allocation of polysorbate 60 molecules in the gel network or significant breakdown of structure (cetyl alcohol systems) due to the transformation of swollen α‐lamellar gel phase into β, γ crystals on 25°C storage. With all fatty alcohols, the consistency of polysorbate 60 ternary system was directly dependent upon interlamellar water thickness as governed by the length and distribution of polyoxyethylene groups within polysorbate 60 molecules. In relation with the composition of polysorbate 60 batches used, the consistency of ternary systems was higher when prepared with the polysorbate 60 batch containing a greater amount of sorbitan polyoxyethylene monoesters. It was proposed that the swollen α‐crystalline gel phase could be better formed by sorbitan polyoxyethylene monoesters rather than sorbitan polyoxyethylene diesters. [ABSTRACT FROM AUTHOR]

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In this work, a cellulose nanofibrils (CNFs)/few-layer graphene (FLG) hybrid is mechanically stripped from bamboo pulp and expanded graphene (EG) using a grinder. This strategy is scalable and environmentally friendly for high-efficiency exfoliation and dispersion of graphene in an aqueous medium. The in situ-generated CNFs play a key role in this process, acting as a “green” dispersant. Next, the obtained CNFs-FLG is used as a functional filler in a polyoxyethylene (PEO) matrix. When the composition of CNFs-FLG is 50 wt.%, the resultant PEO/CNFs-FLG nanocomposite film exhibits a Young’s modulus of 1.8 GPa and a tensile strength of 25.7 MPa, showing 480% and 260% enhancement as compared to those of the pure PEO film, respectively. Remarkably, the incorporation of CNFs-FLG also provides the nanocomposite films with a stunning electrical conductivity (72.6 S/m). These attractive features make PEO/CNFs-FLG nanocomposite films a promising candidate for future electronic devices.

[Display omitted] The aim of this study was to formulate osmotic pump capsules (OPCs) to control the release of nifedipine (NP). NP solid dispersion was prepared by solvent evaporation method. The prepared mixture of NP solid dispersion and various excipients were filled into the commercial HPMC hard capsule shells and then coated with cellulose acetate (CA) solution to form NP-OPC. The CA coating solution consisted of CA as semi-permeable membrane, and Poloxamer 188 as pore formers. The impact of addition agents, citric acid and pore formers on in vitro drug release were investigated. Furthermore, the study has highlighted the impact of paddle speed and the pH value of release media, on the release and compared the release with the commercial controlled release tablets. The in vitro drug release study indicated that drug release could reach 95% in 24 h with optimal formulation, and interestingly model fitting showed that the drug release behavior was closely followed to zero-order release kinetics. The pharmacokinetic studies were performed in rabbits with commercial controlled release tablets as reference, both preparations showed a sustained release effect. Compared with traditional preparation methods of OPCs, the new preparation process was simplified without the operation of laser drilling and the sealing process of capsule body and cap, which improved the feasibility of industrial production. [ABSTRACT FROM AUTHOR]

In order to study the mechanism of the formation of micelle system by the combination of propylene bis (octadecyl dime thylammonium chloride) (abbreviated as 18-3-18),potassium chloride and sodium salicy-late,and to find the viscosity The best ratio of elastic surfactant (VES) fracturing fluid system. In this paper, scanning electron microscope (SEM) is used to observe the microstructure of different components mixed with viscoelastic surfactant, and the viscosity is measured with a viscometer. Find the best ratio, a nd add polyoxyethylen e to hope to further improve its viscoelasticity. The results show that when the concentration of 18-3-18 is fixed at 2 wt %,the potassium chloride content is adjusted to 7 wt %, the sodium salicylate content is at 0. 6 wt %, the formed VES fracturing fluid has the best viscoelasticity, and after adding 0. 1 wt% polyoxyethylene, the viscosity of the system has increased significantly, and the effect is better at high shear rate. [ABSTRACT FROM AUTHOR]

The coexistence of branched chain and EO group will produce oriented variations of film structure and result in the maximum modulus at dynamic curve. The measurements of dynamic surface tensions and surface dilational rheological properties were carried out for four cationic surfactants aqueous solutions, hexadecanol glycidyl ether ammonium chloride (C 16 PC), guerbet alcohol hexadecyl glycidyl ether ammonium chloride (C 16 GPC), hexadecanol polyoxyethylene(3) glycidyl ether ammonium chloride(C 16 (EO) 3 PC) and guerbet alcohol hexadecyl polyoxyethylene(3) glycidyl ether ammonium chloride (C 16 G(EO) 3 PC), using the oscillating bubble method. The influences of surface ageing time, surface pressure, dilational frequency and bulk concentration on surface rheological properties have been expounded. It is found that diffusion-exchange process plays the crucial role for C 16 PC film at all experimental concentrations. On the other hand, the relaxation process in-surface dominates the properties of film at low and high bulk concentration for branched cationic surfactants and C 16 (EO) 3 PC respectively. The branched hydrophobic chain will enhanced the molecular interactions at the surface and improve the value of modulus maximum. The introducing of EO group will produce new relaxation process, such as the variation of orientation of EO group at the surface, which enhances the contributions of viscous nature of film. Moreover, the coexistence of branched chain and EO group will produce oriented variations of film structure and result in the maximum modulus at dynamic curve. [ABSTRACT FROM AUTHOR]

• An epoxy resin and an amine hardener, both, were synthesized from polyethylene glycol. • High degree of thermal stability, mechanical and thermo-mechanical strength was achieved. • Epoxy networks loaded by D230-GO nanoplatelets were also prepared. • D230-GO nanoplatelets could significantly improve the thermal stability and the storage moduli. • The binary epoxy-amine systems provided superior results compared to the single-monomer systems. In this study, three epoxy thermosetting materials possessing polyoxyethylene units are prepared starting from polyethylene glycol. To improve the mechanical strength of the epoxy materials, alongside the flexible units of polyoxyethylene, rigid aromatic and alicyclic moieties arised from two popular monomers are also present into the structures obtained. Thus, epoxide-functionalized polyoxyethylene (EFPOE) and/or diglycidyl ether of bisphenol A (DGEBA) are cured by amine-functionalized polyoxyethylene (AFPOE) and/or isophorone diamine (IPDA). The formulas of EFPOE:DGEBA/AFPOE:IPDA (A), EFPOE/IPDA (B), and DGEBA /AFPOE (C) are stoichiometrically used. To reinforce thermal and thermo-mechanical behaviors, three epoxy networks (D, E, and F) with the same formulas but loaded by 0.5 wt.% of Jeffamine-modified graphene oxide (GO) nanoplatelets are also prepared. In the binary epoxy-amine systems for preparing A and D networks, both resins and hardeners are taken in equimolar amounts. In other systems, leading to B, C, E and F networks, either resin or hardener, just one, is based on polyoxyethylene unites. Heat stability, ultimate tensile strength, elongation at break, and storage moduli (E' values) of the neat epoxy networks as well as the GO-loaded ones were measured and compared with each other. It was found that the epoxy/GO networks, especially that of prepared using binary epoxy-amine systems (network D), have superior thermal properties and greater values of storage modulus (E') around T g and higher temperatures. [ABSTRACT FROM AUTHOR]

Substantial efforts are underway to improve the recovery factor from existing oil reserves to meet the ever‐growing global oil demand. Surfactants are known to increase oil recovery through reducing interfacial tension (IFT) and/or altering the rock wettability. The selection of surfactants for high‐salinity high‐temperature oil fields is a challenging task owing to poor thermal stability, precipitation, and adsorption of surfactants on reservoir rocks. Sulfobetaine‐based polyoxyethylene zwitterionic surfactants have shown excellent thermal and surface properties. However, their solubility in high‐salinity brines becomes poor particularly with a long hydrophobic tail (>C17). Recently, we synthesized such types of surfactants by incorporating ethylene oxide (EO) units into the hydrophobic tail, which improved the solubility in formation water (213,734 ppm) and seawater (SW) (57,643 ppm). In this work, we investigated the IFT, thermal stability, rheological behavior, and foaming properties of two polyoxyethylene zwitterionic surfactants having different degrees of ethoxylation. Aging experiments exhibited excellent thermal stability and no change in the chemical structure was detected. The surfactant with lesser EO units (EASB‐1a) showed a lower IFT compared to the surfactant with higher EO units (EASB‐1b). Rheological studies revealed that the addition of both surfactants reduced the viscosity of the acrylamide copolymer. However, the effect of EASB‐1a was more prominent compared to that of EASB‐1b. The surfactant with a higher degree of ethoxylation showed lower adsorption compared to the surfactant with a lesser degree of ethoxylation. Both surfactants showed excellent foamability and foam stability compared to the commercial surfactants. Excellent thermal stability, water solubility under harsh reservoir conditions, foaming properties, and lower adsorption make them a suitable choice for high‐temperature, high‐salinity reservoirs. [ABSTRACT FROM AUTHOR]

Abstract The surfactant solubility in oilfield water and stability under high-salinity/high-temperature reservoirs faces great challenges. The industrially applied surfactants including petroleum sulfonate, alkyl benzyl sulfonate, and polyoxyethylene ether are suffering due to poor performance in high temperature and high salinity environment. In this study, three betaine based polyoxyethylene zwitterionic surfactants having an unsaturated tail with different ionic headgroups (carboxybetaine, sulfobetaine, and hydroxy sulfobetaine) were synthesized. The structures of the synthesized surfactants were elucidated using FTIR and NMR. The surfactants showed excellent solubility in formation water and sear water and no apparent insoluble surfactants were observed. Thermogravimetric analysis results revealed that the degradation temperatures of the synthesized surfactants were above 290 °C. The critical micelle concentration (cmc) of all surfactants was reduced upon enhancing the temperature, however, the surfactant-containing hydroxy sulfonate headgroup showed the lowest cmc (3.35 × 10−5 mol/L). Similarly, the surface tension at cmc (γ cmc) also reduced upon enhancing the temperature and the surfactant-containing carboxylate headgroup exhibited lowest surface tension (32.24 mN/m). The excellent surface properties and heat stabilities of the betaine type polyoxyethylene zwitterionic surfactants make them a preferred choice for challenging reservoir conditions. Graphical abstract Image Highlights • Synthesis and spectral analysis of polyoxyethylene zwitterionic surfactants containing different ionic headgroups. • Salt resistance and solubility of the synthesized surfactants in high salinity brines. • Thermogravimetric analysis to identify thermal properties. • Influence of different ionic headgroups on cmc, γ cmc , and other surface properties. [ABSTRACT FROM AUTHOR]

Measurements of the surface dilational rheological properties have been carried out for aqueous solutions of four zwitterionic surfactants, hexadecanol glycidyl ether glycine betaine (C 16 PB), guerbet alcohol hexadecyl glycidyl ether glycine betaine (C 16 GPB), hexadecanol polyoxyethylene(3) glycidyl ether glycine betaine (C 16 (EO) 3 PB) and guerbet alcohol hexadecyl polyoxyethylene(3) glycidyl ether glycine betaine (C 16 G(EO) 3 PB), using the oscillating bubble method. The influences of surface ageing time, surface pressure, dilational frequency and bulk concentration on surface rheological properties have been expounded. It is found that the whole hydrophilic part of betaine molecule inclines to flat on the surface when betaine adsorbs, which will lead to higher dilational modulus. The nature of adsorption film is determined by in-surface processes, such as the variation of orientation of hydrophilic group. The branched hydrophobic alkyl chains of betaine molecules improve the intermolecular interactions, not only results in higher moduli, but causes a maximum in dynamic elastic modulus at high concentration. This indicates that the strength of surface film is strongly related to molecular arrangement, not simply determined by the surface molecule concentration. When ethylene oxide groups are incorporated in the hydrophobic group, the enhancement of steric hindrance will decrease both elastic modulus and viscous modulus. [ABSTRACT FROM AUTHOR]

An increasing use of biotherapeutics across a growing spectrum of neoplastic, autoimmune, and inflammatory diseases has resulted in a corresponding increase in hypersensitivity reactions. The origins of anaphylaxis are often attributed to undefined intrinsic properties of the biotherapeutic protein itself, ignoring the broader potential negative contributions of functional excipients, in particular polyoxyethylene containing surfactants such as polysorbate 80 and polysorbate 20 (Tween 80 and Tween 20). These surfactants allow biotherapeutics to meet the stringent challenges of extended shelf-life, increased solubility, protein aggregation prevention, reduced administration volume, and satisfactory reconstitution properties in the case of lyophilized biotherapeutics. The potential negative impact of certain functional excipients on product performance characteristics such as anaphylaxis and immunogenicity is often overlooked. While regulatory authorities understandably focus heavily on comparable efficacy in evaluating biosimilars, similar efficacy does not necessarily imply a similar safety profile between the originator and biosimilar products. Both unwanted immunogenicity and anaphylaxis do comprise major components of safety assessment, however, few if any attempts are made to differentiate drug-related from excipient-related anaphylaxis. The replacement of anaphylactogenic and immunogenic functional excipients with equally effective but safer alternatives will allow biotherapeutic developers to differentiate their biotherapeutic, biosimilar, or biobetter from the large number of nearly identical competitor products, simultaneously providing a substantial commercial benefit as well as critical clinical benefits for all concerned, that is, patients, physicians, and third party payers. [ABSTRACT FROM AUTHOR]

A series of new amphoteric dendrimers have been synthesized by attaching dimethylbenzylaminoethyl acrylate chloride (Bz80), sodium acrylic acid (SAA) and modified polyoxyethylene (MPEO) units to a third-generation poly(amidoamine) (PAMAM) dendrimer core via Michael addition reaction. The structure of the dendrimers was confirmed by Fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), carbon 13 nuclear magnetic resonance (13C NMR) spectroscopy and by elemental analysis. Thermal stability and intrinsic viscosity were investigated. The applicable experiment exhibited the amphoteric dendrimers have high flocculation efficiency, which could be significantly improved by combining amphoteric dendrimers with polyacrylamide (PAM). The suitable mass ratio of the dendrimers and PAM was 2:3. The study would promote the use of amphoteric dendrimers as a flocculant in treating wastewater and as a new paper retention aid in papermaking.

Highlights: [•] Hydrophilic epoxy networks and hydrogels containing polyoxyethylene (POE) and polyoxypropylene (POP) prepared. [•] POE and POP homogeneously built into epoxy network structure. [•] Swelling properties of the epoxy hydrogels strongly controlled by POE/POP ratio and network density. [ABSTRACT FROM AUTHOR]

Abstract: The development of nanotechnology has opened the way for applications in a wide range of fields. Nanoemulsions have attracted great interest because the properties of emulsions are enhanced as the interfacial film approaches equilibrium when formed by droplets of nanometric sizes. In the present study, Solbrax/water/polyoxyethylene nanoemulsions were produced by high-energy emulsification in a high-pressure homogenizer. The droplets of the stable nanoemulsions had diameter size in the range of 7–30nm. These nanoemulsions were used in cleaning of a microporous polymer resin, which can be used to treat oily water. This resin was contaminated with different crude oils. In all cases, the nanoemulsions presented cleaning efficiency above of 90%. [Copyright &y& Elsevier]

When polyoxyethylene-based non-ionic surfactants were added to deionized water, the electrical conductivity of the water increased. The increase was proportional to the surfactant concentration until a maximum value was reached at concentrations between 20∼25%. As long as the macromolecules contained a polyoxyethylene structure (-C-C-O-) there was noticeable molecular polarization in aqueous solution. The highest polarization capacity was observed at surfactant concentrations of 20∼25%. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, the interaction between an antidepressant drug amitriptyline hydrochloride and nonionic polyoxyethylene surfactants, with special attention to the possible contribution from the ion–dipole type of interaction, has been investigated by using multitechnique approach. Tensiometric and conductometric studies show steeper decrease on the critical micellar concentration gradient of the drug in the presence of electrolyte (NaCl) as well as nonionic surfactants. Critical assessments by applying Clint, Rubingh, Rosen, Motomura and other thermodynamic models confirm strong interactions in the mixed monolayer at the surface and in mixed micelle in the bulk of aqueous electrolytic solution. The structural difference in the drug and nonionic surfactants also plays a role in tuning the aggregational behavior of the drug–surfactant mixtures. Finally, it is shown by DLS measurements that the micellar growth of drug–surfactant aggregates is favored in terms of increase in hydrodynamic radii in the presence of electrolyte. However, the nonionic surfactants provide sufficient steric crowding causing dissociation of larger micelles into smaller ones with small radii. [Copyright &y& Elsevier]

Activity coefficients of solvents and solutes in different aqueous solutions of alcohols and polymers are determined by molecular dynamic simulations. These data are often not accessible by simulation due to unacceptably high computational demands. Therefore, we applied a combination of two methods: water activity coefficients were determined directly via Overlapping Distribution Method, while counter-component activity coefficients were calculated indirectly by Gibbs-Duhem integration of the respective water activities. Results are in good agreement with experimental data. The method can easily be applied to determine activity coefficients of very complex components in water or other simple solvents. [ABSTRACT FROM PUBLISHER]

Abstract: A series of anionic gemini surfactants called (oligooxa)-α,ω-bis(m-alkylbenzene sulfonate) with different length in spacer and in hydrophobic chain, C8E x C8 (x =1, 2, 3, 4, 8) and C n E4C n (n =8, 10, 12), have been synthesized from 4-n-alkylphenol and their basic physicochemical properties are investigated. The results indicate that they are different from cationic gemini surfactants called (oligooxa)alkanediyl-α,ω-bis(dimethyl-dodecylammonium bromide), 12-CH2CH2(EO) s -12, in the literature. As the number of oxyethylene segments increases, the cmc (critical micelle concentration) decreases initially and then increases, and the surface area per molecule decreases initially and then tends to a constant value of approximate 1.30nm2. Both of the breakpoints appear at number 4 of oxyethylene segments in the spacer. It is confirmed that the hydrophilic spacer with oxyethylene moieties is not fully extended at the air–water interface. With increasing spacer length, the spacer becomes sufficiently flexible to adopt a particular conformation with a loop at the water side of the air–water interface. The fluorescence data show that the micropolarity increases little from C8E1C8 to C8E4C8 and decreases obviously when x changes from 4 to 8. In addition, the plot of the logarithm of the cmc against the alkyl chain length for C n E4C n shows a linear decrease with the increase in chain length. The micropolarity of the gemini surfactants (C n E4C n ) decreases with an increase in the alkyl chain length (n from 8 to 12). [Copyright &y& Elsevier]

Abstract: 1H NMR permits some approaches to a monomer unit scale of the macromolecular grafted on the solid. In the case of poly(ethylene) grafted on silica, the magic angle spinning technique confirms, by narrowing of the central line and apparition of side bands, the existence of the residual dipolar interaction, which reveals the high monomer unit concentration at the surface. The study of the side bands permits calculation of the physical parameter: the second moment, which gives in turn an indication of the evolution of the monomer unit concentration on the surface. This behavior has been studied as a function of molecular weight of the chains and grafting ratio. A fair agreement is obtained for the second moment and the linewidth, giving a consistent picture by two independent techniques: magnetic relaxation and magic angle spinning. [Copyright &y& Elsevier]

The liquid crystal (LC) alignment properties of LC cells fabricated with films of n-alkylsulphonylmethyl-substituted polyoxyethylenes (#S-PEO, # = 4, 6, 7, 8 and 10), where # is the number of carbon atoms in the n-alkyl side groups having different n-alkyl chain length, were investigated as a function of the rubbing density. The LC cells made from unrubbed #S-PEO (# ≥8) films having more than eight carbon atoms in the n-alkyl side groups showed homeotropic LC alignment. The homeotropic LC alignment behaviour correlated well with the surface energy values of the unrubbed #S-PEO films; homeotropic LC alignment was observed when the surface energy values of the unrubbed #S-PEO films were smaller than about 21.62 mJ m-2. The LC cells made from rubbed #S-PEO (# ≥7) films having more than seven carbon atoms with a rubbing density of 150 showed homeotropic LC alignment. It was also found that the tilt angle of the LCs on the rubbed #S-PEO films was affected not only by the n-alkyl chain length of the polymers, but also by the rubbing density, regardless of the surface energy value of the #S-PEO film. [ABSTRACT FROM AUTHOR]

Abstract: Emulsion polymerization of styrene was carried out using two kinds of alkyl polyoxyethylene ether sulfosuccinates as surfactant: disodium cetyl polyoxyethylene (25) ether sulfosuccinate (CPS) and octyl-phenol polyoxyethylene (10) ether sulfosuccinate (OPS). In experiments, the incorporation of CPS or OPS inside styrene droplets and polystyrene particles was clearly observed. Based on this phenomenon, multihollow polymer spheres are prepared in a one-step reaction and this strongly supports the proposed incorporation mechanism. CPS is more effective than OPS during the preparation of multiporous spheres. This difference between the two surfactants mainly contributes to the difference of the length of the EO (polyoxyethylene) group, which can determine the affinity among surfactant, styrene, and water molecules. [Copyright &y& Elsevier]

Abstract: The 1H NMR technique is used to study the behaviour and dynamics of the poly(ethylene oxide) chains grafted chemically on silica. A noticeable influence of the different physicochemical parameters on the dynamics and the conformation of the grafted macromolecules is evidenced. The grafting ratio, the temperature, the solvent can all in well-chosen situations modify the configurations and dynamics of the chains. The temperature dependence of the 1H NMR spin–lattice relaxation time is analyzed for preliminary evaluation of the correlation time of the local dynamics of the polymeric chains and for three significant grafting ratios. The magic-angle spinning technique is used to study the dynamics of the macromolecules at the interface. It permits to determine two correlation times for each grafting ratio: τ sl characteristic of an environment with a slow motion and τ fa characteristic of the local segmental motion. This last correlation time is compared to that obtained by measurements of T 1. [Copyright &y& Elsevier]

Oxyethylene (PEO)/oxypropylene (PPO) triblock polymers are added to colorant formulations to determine the influence of molecular weight and other structural variances on the rheology and color development of tinted latex paints. Waterborne coatings are a matrix of many coating components. In this study, a 108- or a 600-nm latex was thickened with a nonassociative thickener, hydroxyethyl cellulose, or an associative telechelic HEUR thickener. Triblock polymers with internal PPO segments and PEO terminal segments added as a dispersant to colorant packages, lead to better color development than PPO/PEO/PPO triblocks dispersants in carbon black (CB) tinted paints. The increase in color development with high molecular weight (MW) triblocks starts at a very low concentration (2 mM) and plateaus in a Langmuir-type adsorption isotherm. Lower molecular weight triblock polymers also exhibit this behavior in CB-, red-, and yellow-tinted latex coatings: however, increasing the terminal PEO segment sizes leads to better color development only in the CB-tinted coatings. With large PEO terminal units red and yellow tints are high only at very low concentrations (2mM) of the triblock. This parabolic response in color development, in contrast to CB-tinted formulations, is attributed to the high surface area and porosity of CB that limits the amount of large PEO segments interacting with the talc particle present at twice the volume fraction of the colorant. With the lower surface areas of the red and yellow colorants, the interaction of the large PEO terminal segments with talc particles accounts for the limited triblock concentration for which good color development is observed. This can be reversed by decreasing or eliminating talc from the formulation. [ABSTRACT FROM AUTHOR]

Abstract: This work proposes the use of X-ray fluorescence with total reflection geometry to explore the metal ions transport in aqueous hydrophilic polymer solutions. It is centered in the study of polymer concentration influence on ion diffusion. This subject is relevant to various and diverse applications, such as drug controlled release, microbiologic corrosion protection and enhanced oil recovery. It is anticipated that diffusion is influenced by various factors in these systems, including those specific to the diffusing species, such as charge, shape, molecular size, and those related to the structural complexity of the matrix as well as any specific interaction between the diffusing species and the matrix. The diffusion of nitrate salts of Ba and Mn (same charge, different hydrodynamic radii) through water-swollen polymeric solutions and gels in the 0.01% to 1% concentration ranges was investigated. The measurements of the metal concentration were performed by TXRF analysis using the scattered radiation by the sample as internal standard. Results are discussed according to different physical models for solute diffusion in polymeric solutions. [Copyright &y& Elsevier]

The modification of acid anhydride-cured epoxy resin with poly[poly(N-phenylmaleimide-alt-styrene)-block-polyoxyethylene] (PMSE) prepared by in situ polymerization was carried out in order to increase the toughness of the cured epoxy resin without loss of flexural strength. The modification with PMSE resulted in microscopic two-phase morphology with PMSE-rich spherical particles dispersed in the epoxy-rich matrix. The introduction of polyoxyethylene segments into the modifier brought about the increased interfacial interaction between the epoxy matrix and the modifier, thereby increasing the fracture toughness of the modified resin by 180%, compared with the unmodified resin, with substantial retention of flexural strength. The addition of a small amount of divinylbenzene to the in situ polymerization system induced the formation of IPN structures at the interface between the matrix and the modifier, resulting in the increased fracture toughness. The flexural modulus and glass transition temperature of the modified epoxy resin were comparable to those of the unmodified resin. [ABSTRACT FROM AUTHOR]

Abstract: A surfactant/polymer wall coating consisting of the doubly chained cationic surfactant dimethyldioctadecylammonium bromide (DODAB) and polyoxyethylene (POE) 40 stearate is investigated. The coating is formed by simply rinsing a capillary with a solution containing DODAB and POE 40 stearate. The resultant coating is semi-permanent—demonstrating stable electroosmotic flow (EOF) even after a 60min high pressure rinse with buffer. The EOF (−0.45±(0.23)×10−4 cm2 V−1 s−1 at pH 7.4) is suppressed by more than a factor of ten compared to that observed for DODAB alone. Model protein mixtures were separated over a pH range of 3–10 with efficiencies of up to greater than 1 million plates/m for the basic proteins cytochrome c, lysozyme, ribonuclease A and α-lactalbumin, and the acidic proteins insulin chain A, trypsin inhibitor, and α-chymotrypsinogen A. Migration time reproducibility was 0.5–4.0% from run to run and 0.6–4.3% from day to day. Protein recoveries with this coating ranged from 84% to 97%. [Copyright &y& Elsevier]

Abstract: We have examined the impact on biological systems of some newly synthesised polyoxyethylene polymers using in vitro assays. Toxicity was tested by the 3-[4,5-dimethylthiazole-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay, haemolysis was assessed, and an ethidium bromide (EB) assay was used to study interactions between the polymers and DNA. All the assay data showed that the polymers are biocompatible. No differences were found between generations (i.e. macromolecule sizes). The results encourage continuing studies on the clinical use of these molecules as drug carriers. [Copyright &y& Elsevier]

Abstract: A means to produce extruded–spheronized beads, devoid of microcrystalline cellulose (MCC) and with a high drug load (greater than 80%, w/w), is presented. Immediate release bead product with a high yield (greater than 60% of 1mm diameter beads) and low friability (mass loss less than 4.0%) that were spherical to the naked eye (roundness score less than 1.20) were obtained. The formulation consists only of water-soluble components, taking advantage of the properties of soluble polyethylene oxide (PEO) and methoxypolyethylene glycol (MPEG). This approach incorporates minimal processing aids, with wetted PEO providing the apparent plasticity and cohesiveness, and MPEG550 providing the apparent self-lubricating characteristics necessary for successful extrusion and subsequent spheronization into beads. The success of this approach has important implications in cases where high drug load beads are desired, but where MCC cannot be used due to chemical incompatibility or where complete release cannot be achieved with MCC-containing beads. [Copyright &y& Elsevier]

The micellization process of binary mixtures formed by polyoxyethylene monododecyl ether (C 12 E n ; n=12 and 15) and different ionic surfactants, anionic sodium dodecyl sulfate (SDS) and cationic hexadecylpyridinium bromide (CPB), was examined by using surface tension and viscosity measurements. Rubingh's nonideal solution theory predicted nonideal mixing and attractive interaction between the constituent surfactants in the mixed micelle. In the single systems, the relative viscosity of nonionic surfactant is greater than that of the ionic surfactant and increases with the increasing level of ethylene oxide. In the mixed surfactant systems, the relative viscosities vary at a mixed molar fraction between 0.2 and 0.3, and then the relative viscosities of mixed systems decrease with the increasing mole fraction of ionic surfactants. The experimental viscosity values show a positive deviation from ideal behavior because of mixed micelle formation and the electroviscous effect. This effect could be suppressed by the addition of NaCl. [ABSTRACT FROM AUTHOR]

A series of blends of polyoxyrnethylene (POM)/thermoplastic polyesterurethane (TPU) has been obtained by mechanical processing using a double screw extruder. The thermal stability and the thermal degradation profiles of POMITPU blends were investigated by thermogravimetric analysis (TG) coupled on-line with Fourier transform infrared spectroscopy (ETIR). It was found that incorporation of TPU into POM matrix resulted in increase of thermal stability of blends in comparison with pristine materials. The thermal degradation of TPU in inert gas atmosphere proceeds in two steps while the thermal degradation of POM is basically a one step process with a substage in a higher temperature range. The most abundant volatile products of the thermal degradation were identified; the possibly routes of their formation have been presented. [ABSTRACT FROM AUTHOR]

A mixture of three polyethylene oxides bearing alkyl chains of different lengths C12H25O(CH2CH2O)nH, C16H33O(CH2CH2O)nH, C18H37O(CH2CH2O)nH have been analyzed by different techniques: two-dimensional LC, MALDI-TOF, ESI-MS and LC-MS. Among these techniques, the LC-MS coupling allowed the fastest analysis (4 min versus 2 h in two-dimensional LC). In addition, the complexity of the mass spectra deduced from LC-MS experiments was simplified compared to the mass spectra obtained by MALDI-TOF and ESI-MS. Overlaps of isobaric ions were avoided and by-products were identified more easily. [ABSTRACT FROM AUTHOR]

A novel direct spectrophotometric method is developed to determine traces of polyoxyethylene non-ionic surfactants (such as Triton X-100) in environmental water. It is based on the formation of a ternary complex, Meso-tetra (3,5-dibromo-4-hydrooxylphenyl) Porphyrin (T (DBHP) P)-Pb (II)-Triton X-100 in NaOH medium. Under the optimum reaction conditions, T (DBHP) P-Pb (II) complex reacts with Triton X-100 to form a yellow ternary complex immediately. The complex, which has a maximum absorption peak at 479 nm, is stable for at least 24 h. The mean molar absorption coefficient and the limit of detection for Triton X-100 is 1.1 × 10 4 L mol -1 cm -1 and 0.02 µg mL -1 , respectively. Beer's law is obeyed in the concentration range of 0-0.5 mg mL -1 Triton X-100. It is found that all the studied coexisting substances, especially cationic and anionic surfactants, which always seriously interfere in some reported methods, can be tolerated in considerable amounts. The method is used for the direct determination of PE in environmental water and has a good precision and accuracy. [ABSTRACT FROM AUTHOR]

Reaction‐induced, phase separation has been studied in polymer blends. A model crystalline‐amorphous system consisted of semicrystalline polyoxyethylene (POE) dissolved in the monomer styrene, which was used as a reactive solvent to ease processing. When the styrene was polymerized to polystyrene (PS) in the mold, phase separation and phase inversion are induced, and a polymer blend was formed. Polyoxyethylene was selected with a molar mass, Mn = 8578 g mol−1 and a polydispersity of 1.19, as determined by using gel permeation chromatography. The polymerization of styrene was initiated by using 1 wt% benzoin methyl ether and 0.2 wt% 2,2′‐azobisisobutyronitrile under ultraviolet light. The polymerization kinetics were determined by monitoring the reduction in the intensity of the C˭C stretching vibration band at 1631 cm−1 in the Raman spectrum of styrene. The onset times for the liquid–solid (L–S) phase separation and crystallization of POE from styrene/PS were observed by using simultaneous small‐angle x‐ray scattering (SAXS) and wide‐angle x‐ray scattering. Onset times for L–S phase separation determined from the SAXS data were combined with the styrene polymerization kinetics to plot the L–S phase separation data onto a ternary phase diagram for the reactive system POE/styrene/PS at 45°C and 50°C. #Presented at the Synchrotron Radiation in Polymer Science II Conference, Sheffield, UK, 4–6 September 2002. [ABSTRACT FROM AUTHOR]

The morphology development in model polymer blends was investigated in relation to the processing pathway. Reaction‐induced phase separation was used to make polyoxyethylene (POE) and polystyrene (PS) blends from a solution of POE/styrene. As the styrene underwent polymerization by photo‐initiation with ultraviolet light, phase separation, and phase inversion were induced, whereby the POE became the matrix phase. Optical microscopy showed that liquid–liquid (L–L) phase separation occurred soon after the styrene polymerization was initiated. Nucleation and growth was identified as the mechanism of L–L phase separation. Polystyrene/styrene‐rich domains formed in a POE/styrene‐rich matrix. The domain size developed until arrested by the POE liquid–solid phase separating and crystallizing, since the experiments were conducted below the melt temperature of POE. The POE crystal growth process also followed a nucleation and growth mechanism. The time to the onset of crystallization was observed to decrease as the POE content increased, until the POE formed a saturated solution in styrene. As the crystallization onset time decreased, the PS‐rich domain size also decreased. The phase diagram previously established can now be used to describe (and predict) the number density and size of the PS‐rich domains in the POE matrix of the blends. #Presented at the Synchrotron Radiation in Polymer Science II Conference, Sheffield, UK, 4–6 September 2002. [ABSTRACT FROM AUTHOR]

Polystyrene-supported polyoxyethylene (PSPOE) bound permanganate with varying crosslinking agents have been prepared and used as a new class of recyclable oxidizing agents for low molecular weight alcohols and aldehydes. The effect of the nature of crosslinking agents on the oxidation reactions was studied in detail. The crosslinking agents used were ethyleneglycol dimethacrylate (EGDMA), 1,4-butanediol dimethacrylate (BDDMA), and 1,6-hexanediol diacrylate (HDODA). Polymer supports were synthesized by free radical suspension polymerization. Chloromethylation was done using the Friedel-Crafts reaction. A cyclic polyether type compound was developed by the reaction of functionlized resin with polyethylene glycol (PEG600) and sodium. Polystyrene-supported polyoxyethylene was equilibrated with potassium permanganate in benzene to give the oxidizing agent. The results reveal that the reactivity of HDODA-crosslinked system shows higher reactivity than the BDDMA, and EGDMA-crosslinked systems. This is due to higher flexibility of the HDODA-crosslinked system compared to the BDDMA, and EGDMA-crosslinked systems. The effect of solvent, temperature, and molar concentration of the reagent on oxidation were carried out using benzoin to benzil as the model reaction. For a less flexibile EGDMA-crosslinked resin, tetrahydrofuran (THF) is the best solvent, for BDDMA-crosslinked system dioxane and for the highly flexible HDODA-crosslinked system CHCl3 is found to be best. In all cases, the reactivity of the reagent increased with an increase in temperature and molar excess of the reagent. [ABSTRACT FROM AUTHOR]

Alternating amphiphilic multiblock copolymers, consisting of polyoxyethylene (POE) and poly(ε-caprolactone) (PCL) of various lengths, were synthesized by a polycondensation reaction between dicarboxylated PEG and dihydroxyl PCL. The polymer formed a physical hydrogel by PCL crystallization. For in vitro hydrolysis in phosphate-buffered saline solution, the change of molecular weight depended on the composing block length of POE. The polymer with longer POE showed a faster decline in molecular weight. The mass remaining at the end of two weeks at 25°C was more than 95 wt%. However, when the swollen hydrogels were exposed to temperatures slightly above PCL melting point for 30 min, the degradation rate was accelerated and the mass remaining dropped to less than 10 wt% in one week. In vivo degradation after hydrogel implantation, the polymer degraded as under in vitro. However, the implant irradiated with infrared (IR) accelerated its degradation similar to a treatment with elevated temperature. [ABSTRACT FROM AUTHOR]

As a part of a study of the colloidal structures present in nonionic ointments, the interaction between polyoxyethylene and water is investigated. A series of mixtures of polyoxyethylene 1550 and water is studied using differential scanning calorimetry. Heating as well as cooling experiments are performed. The effects of the heat of mixing, supercooling and melting point depression on the measured enthalpy changes are discussed. From the non-freezing water fraction it is concluded that 2 water molecules per oxyethylene unit are tightly bound to the polymer chain. The observed differences between the cooling and the heating curves lead to a possible explanation for the alterations in the samples occurring at low temperatures. A hydrate structure of polyoxyethylene at low temperatures is proposed. Finally, comment is made on the phase diagram of the system polyoxyethylene/water. [ABSTRACT FROM AUTHOR]

Previous studies have shown that polyoxybutylene surfactant hydrophobes are less polar than polyoxypropylene hydrophobes. Polyoxyalkylene hydrophobes can be modified by ethoxylation to give terminal polyoxyethylene block hydrophilic groups. Polyoxybutylene/polyoxyethylene copolymer surfactants exhibit differentiated interfacial tensions, and wetting and foaming properties when compared to structurally equivalent polyoxypropylene/polyoxyethylene copolymers. There have been no reported comparisons, however, of polyoxybutylene/polyoxyethylene copolymers and polyoxypropylene/polyoxyethylene analogues in terms of fundamental parameters, such as critical micelle concentration, area per molecule at the interface, efficiency, and effectiveness. In one phase of this work, four polyoxybutylene/polyoxyethylene block copolymer surfactants were compared to structurally analogous polyoxypropylene/polyoxyethylene materials. Findings showed that polyoxybutylene/polyoxyethylene copolymers exhibited enhanced cotton wetting and lower surface and interfacial tensions compared to polyoxypropylene/polyoxyethylene analogues. Polyoxybutylene-based surfactants were typically one order of magnitude better in their ability to reduce surface tension at interface saturation. Polyoxybutylene/polyoxyethylene copolymers pack more efficiently at the interface, as evidenced by a smaller area per molecule at the interface. Critical micelle concentration values were also lower for polyoxybutylene/polyoxyethylene copolymers. A second phase of experiments focused on the surface activity of polyoxypropylene/polyoxyethylene triblock copolymers with higher molecular weight hydrophobes. Enhanced surface activity was found when compared to lower-molecular weight polyoxypropylene/polyoxyethylene copolymers. [ABSTRACT FROM AUTHOR]

The utility of amino acids and dipeptides esterified to solubilizing polyoxyethylene supports as substrates for protease-mediated peptide bond formation was studied using free and immobilized α-chymotrypsin as a catalyst. Poor yields were obtained with N-protected amino acid or dipeptide polyoxyethylene esters as carboxyl components, most probably due to a shielding of the active site of the acyl enzyme intermediate by the polymer favouring hydrolytic cleavage. Experiments with polyoxyethylene esters as nucleophiles gave good results with free chymotrypsin, immobilized chymotrypsin predominantly caused hydrolysis of the ester carboxyl component due to unfavourable interactions between the soluble and insoluble polymers. [ABSTRACT FROM AUTHOR]