Properties Of Hydrophilic Polymers Research Articles

Hydrophilic polymers: interactions with lipid layers and ferning patterns

AbstractPurposeTo evaluate (i) the mucomimeticity of pharmaceutically applicable hydrophilic polymers (HP) as well as (ii) their interactions with human meibum films.MethodsFour HP were used‐hyaluronic acid (HA), cross‐linked hyaluronic acid (CHA), carboxymethyl cellulose (CMC) and gellan gum (GG)‐ at the concentrations of 0.0001, 0.001,0.01,0.05, 0.1%. HP mucomimeticity was probed by the formation of tear‐like ferning patterns (TFP) after HP solution drop evaporation. The interactions between HP and meibum at the air/water interface were examined in vitro at blink‐like compression/expansion of the film area by Langmuir surface balance. Surface pressure (π)‐area (A) isocycles and stress relaxations were used to assess the sample’s lateral elasticity and reorganization during area cycling. Films morphology was monitored by Brewster Angle Microscopy (BAM).ResultsSignificant differences were observed in the capability of HP to form ferning patterns: CHA (≥0.001%) > HA (≥0.01%) = CMC (≥0.01%) > GG (≥0.05%). CHA, HA, CMC and GG enhanced the uniform spreading of meibomian layers as well as their elasticity and rapid reorganization at blink like area cycling in concentration dependent manner. BAM micrographs revealed considerable thickening of the meibomian films in the presence of HP.ConclusionsThe combination of tear ferning and Langmuir surface balance studies allows to simultaneously evaluate the mucomimetic and the lipid interaction properties of HP. TFP forming polymers enhanced both (i) the uniform spreading and structure of meibomian layers and (ii) their dynamic surface properties. Cross‐linking HA was particularly efficient both in ferning pattern and meibomian film systems.

Synthesis and properties of hydrophilic polymers, part 11: Synthesis, biodegradability, and metal complexation of copolymers of ethylenediaminetetraacetic acid dianhydride and lactose

AbstractThe synthesis and characterization of poly(ethylenediaminetetraacetic acid‐co‐lactose) of high molar mass (132 kg mol−1) is described. The polycondensate with pendant carboxylic groups was shown to be hydrolytically and microbiologically degradable by using conventional microbiological methods. The metal complexing properties of the polyester were studied for Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II), Pb(II), and Al(III) ions in aqueous solution using the liquid‐phase polymer‐based retention (LPR) method. In addition, the complexing capacity of the Cu(II)‐saturated copolymer was determined by TGA to be 182 mg g−1 polymer. According to the retention profiles determined as a function of filtration factor by using LPR in conjunction with inductively coupled plasma spectrometry, Cr(III) and Fe(III) showed a strong interaction with this polymer under these conditions, indicated by retention values of 100% at pH 5. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2932–2939, 2007

Synthesis and properties of hydrophilic polymers. IX. Synthesis, biodegradability, and metal complexation of copolymers of ethylenediaminetetraacetic acid dianhydride and lactose

AbstractThe synthesis and characterization of poly(ethylenediaminetetraacetic acid‐co‐lactose) with pendant carboxylic groups of high molar mass (132 kg mol−1) is described. The polycondensate was hydrolytically and microbiologically degradable with conventional microbiological methods. The metal‐complexing properties of the polyester were studied for Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II), Pb(II), and Al(III) ions in aqueous solution with the liquid‐phase polymer‐based retention (LPR) method. In addition, the complexing capacity of the Cu(II)‐saturated copolymer was determined by thermogravimetric analysis to be 182 mg g−1 of polymer. According to the retention profiles determined as a function of the filtration factor with LPR in conjunction with inductively coupled plasma spectrometry, Cr(III) and Fe(III) showed a strong interaction with this polymer under these conditions, as indicated by retention values of about 100% at pH 5. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 650–657, 2003

Synthesis and Properties of Hydrophilic Polymers, 10

AbstractWater‐soluble poly[(N‐maleoylglycine)‐co‐(hydroxyethyl methacrylate)] was employed for the separation of a series of metal ions in the aqueous phase using the liquid‐phase polymer‐based retention method. The method is based on the retention of inorganic ions by this polymer in conjunction with membrane filtration and subsequent separation of low‐molecular‐mass species from the polymer complex formed. It is shown that the polymer can bind several metal ions in aqueous solution at pH 3, 5, and 7, for example Cr(II), Co(II), Zn(II), Ni(II), Cu(II), Cd(II), Pb(II) inorganic ions. The interaction of the inorganic ions with the hydrophilic polymer was determined as a function of pH and filtration factor. The water‐soluble polymeric reagent with strong metal‐complexing properties was synthesized and used to separate complexed from non‐complexed ions in the homogeneous phase. The polymer exhibited high retention capability at pH 5 and 7. It was characterized by elemental analysis, FT‐IR, 1H NMR, and 13C NMR spectroscopy, as well as by thermogravimetry. Additionally, viscosimetric measurements of the copolymer were performed at different pH values. magnified image

Synthesis and properties of hydrophilic polymers. Part 7. Preparation, characterization and metal complexation of carboxy-functional polyesters based on poly(ethylene glycol)

Novel water-soluble polyesters with pendant carboxylic groups were synthesized by polycondensation of ethylenediaminetetra-acetic acid (EDTA) dianhydride and diethylenetriaminepenta-acetic acid (DTPA) dianhydride with poly(ethylene glycol)s of different chain-lengths. Two experimental approaches (polycondensation using various solvents and in the melt) were studied, and melt condensation was found to give higher yields of polyesters. The polymeric products were soluble in water, acetone, chloroform and toluene, and were characterized by elemental analysis, IR and NMR spectroscopy. In addition, the carboxyl functionalities were determined by titration and the hydrolytic stability studied as a function of pH. The complexing capacity of the functional polyesters was determined in dependence of pH for copper in aqueous solution using the Liquid-Phase Polymer-Based Retention (LPR) technique and found to be 257 mg g−1 for the EDTA-based copolymer at pH 5 and 230 mg g−1 for the DTPA-based copolymer, respectively. © 1999 Society of Chemical Industry

Moisture Vapor Transport Through Waterproof Breathable Fabrics and Clothing Systems Under a Temperature Gradient

Moisture vapor transport through waterproof breathable samples and clothing sys tems under a temperature gradient is examined using a simple research method. The results are compared with those obtained from isothermal tests. The transport properties are identified as being dependent on the temperature gradient across the waterproof breathable layer, the humidity of the clothing microclimate, and the interaction between water vapor and the clothing layers. The transport properties of hydrophilic polymers and clothing systems incorporating hydrophilic polymers, especially those with low transmission rates in the isothermal tests, improve by considerably greater amounts than those incorporating microporous polymers when a temperature gradient is applied.

Synthesis and properties of hydrophilic polymers, 5. Viscosimetric study on poly(acrylamide-co-4-vinylpyridine) and its interaction with metal ions in aqueous solution

Poly(acrylamide-co-4-vinylpyridine) synthesized by radical bulk polymerization behaves in water as a typical polyelectrolyte. According to the viscosimetric studies, the addition of strong electrolytes, like KNO3 (0.1 M), completely suppressed the polyelectrolyte effect. The interactions between this copolymer and a number of metal ions were also studied by viscosimetry in aqueous solution. The reduced viscosity decreased with an increase of the copper(II) concentration due to an intrapolymeric complex formation. It was shown that the reduced viscosity of the polymer-metal complexes depends on the pH. It decreased for a constant ratio between the copolymer and the metal ions Fe3+, Co2+, Ni2+, Cu2+, and Zn2+. Among these cations, Cu2+ showed the strongest effect. These results were compared with the corresponding data of both homopolymers. Durch radikalische Polymerisation in Substanz hergestelltes Poly(acrylamid-co-4-vinylpyridin) verhält sich in Wasser wie ein typischer Polyelektrolyt. Nach den Viskositätsuntersuchungen wurde der Polyelektrolyteffekt durch die Zugabe von starken Elektrolyten wie KNO3 (0,1 M) vollständig unterdrückt. Die Wechselwirkungen zwischen diesem Copolymeren und einer Reihe von Metallionen wurden viskosimetrisch in wäßriger Lösung untersucht. Dabei nahm die reduzierte Viskosität aufgrund einer intrapolymeren Komplexbildung mit zunehmender Kupferkonzentration ab. Es wurde gezeigt, daß die reduzierte Viskosität der Polymer-Metallkomplexe vom pH-Wert abhängt. Sie nahm ab bei einem konstanten Verhältnis zwischen Copolymerem und den Metallionen Fe3+, Co2+, Ni2+, Cu2+ und Zn2+, wobei Cu2+ den stärksten Effekt innerhalb dieser Reihe zeigte. Diese Ergebnisse wurden mit den entsprechenden Daten der beiden Homopolymeren verglichen.

Synthesis and properties of hydrophilic polymers, 6. Water-soluble polypyrrole graft copolymers with electrical conductivity

A novel method for the preparation of water-soluble polypyrrole graft copolymers with polyamines or polyimines is described. The polyreaction is performed in acidic solution by using chemical oxidants, e.g. iron(III) chloride or ammonium peroxodisulfate. The graft copolymers showed electrical semiconductivity in the undoped state which can be placed between the high conductivity of polypyrrole and the nonconductivity of the polyimine. Their thermal stability at 250°C is improved compared to polypyrrole. The novel graft copolymers are soluble in water over a wide pH range and have a good processability.

Synthesis and Properties of Hydrophilic Polymers. 4. Preparation and Characterization of Poly(Oxyethylene) Telechelics with Different Aromatic Termini

Abstract Several telechelic compounds were prepared by terminal functionalization of poly(oxyethylene) diacid via the reaction of the carboxylic groups with different aromatic amines. Starting from the telechelic diacid, the corresponding diacid chloride was prepared with thionyl chloride after which the compound was allowed to react with aniline, 2-naphtylamine, and 2-aminoanthracene. The telechelic products were characterized by UV/Vis, 1H-NMR, 13C-NMR, and IR spectroscopy. The UV/Vis spectrometric data were compared to those of the corresponding amines. In addition, refractive indices and solubility characteristics were also determined. In addition, the spectroscopic data were compared with respect to increasing terminal chain extension by the three aromatic compounds.

Synthesis and properties of hydrophilic polymers. III. Ligand effects of the side chains of polyaziridines on metal complexation in aqueous solution

The metal-complexing properties of five different polyaziridines—poly[1-(2-aminoethyl)aziridine], poly(1-acetylaziridine), poly[1-(2-hydroxyethyl)aziridine], poly[1-(2-hydroxyethyl)aziridine-co-1-acetylaziridine], and poly[1-(2-aminoethyl)aziridine] oxine—were investigated in an aqueous solution with regard to the side-chain effects using membrane filtration. The results are discussed and compared with the stability constants of metalcomplexation of the corresponding functional moieties. Poly[1-(2-aminoethyl)aziridine], a poly(aziridine) with neutral nitrogen donors in the side chains, showed similar complexing properties to those of ammonia. The only exceptions are Fe(III) and Cr(III), which cannot form complexes with ammonia but can be retained in the membrane filtration process due to the formation of Fe(III)-colloidal species and hydroxides. The complexing properties of polyaziridines containing hydroxyl groups in the side chains (i.e., poly[1-(2-hydroxyethyl)aziridine] and poly[1-(2-hydroxyethyl) aziridine-co-1-acetylaziridine] can be explained and described by the formation constants with the corresponding hydroxides. The introduction of a carbonyl moiety in the polyaziridine side chain, e.g., polyacetylaziridine, reduces the complexing ability for metal ions because the carbonyl group cannot form complexes with the metal ions investigated. Poly[1-(2-aminoethyl)aziridine]oxine showed the strongest complexing ability in the series of metal ions due to the strong complexing ligand 8-hydroxy quinoline attached to the polymer backbone. © 1996 John Wiley & Sons, Inc.

Synthesis and properties of hydrophilic polymers, 2 synthesis of polymeric surfactants based on the mannich reaction with amino polymers

Polymeric surfactants [CH 2 CH 2 N([CH 2 ] 2 N[CH 2 OH]R)] m [CH 2 CH 2 N(CH 2 R)] n [CH 2 CH 2 N(CH 2 OH)] o (R= C 5 H 5 N + -C 16 H 25 , Ph(C 12 H 25 )(SO 3 Na)) are synthesized by polymer analogous modification of polyethyleneimine with anionic and cationic surfactants

Synthesis and Properties of Hydrophilic Polymers I. Preparation and Metal Complexation of Poly(4-vinylpyridine-co-N-allylthiourea)

Copolymers of 4-vinylpyridine and N-allylthiourea with different mole fractions were synthesized by radical copolymerization in bulk. The AIBN-initiated copolymerization was found to strongly favor the 4-vinylpyridine monomer in the copolymer composition. This was confirmed by viscosity measurements with a linear relationship between the reduced viscosity and the comonomer content. Interactions and complexation of the water-soluble copolymers with nine metal ions were investigated in aqueous solution by means of a membrane filtration technique. This technique is designed to remove and separate metal ions from diluted solutions by binding them to soluble polymers. The effects of several parameters, such as copolymer composition, filtration factor, and pH were studied as a function of the interaction of the copolymers with metal ions. A strong selectivity for copper(II) was found which was pronounced at a monomer ratio of 1:2 (4-vinylpyridine: N-allylthiourea). Also a partial interaction of iron(III) and the copolymer (2:1) was observed at pH 3 which was strongly pH-dependent.

Structure and properties of hydrophilic polymers and their gels. XIV. Viscoelastic behaviour of swollen poly(ethylene glycol monomethacrylate) networks in the main transition region

Structure and properties of hydrophilic polymers and their gels. XIV. Viscoelastic behaviour of swollen poly(ethylene glycol monomethacrylate) networks in the main transition region

Structure and properties of hydrophilic polymers and their gels. XI. Microsyneresis in swollen poly(ethylene glycol methacrylate) gels induced by changes of temperature

Structure and properties of hydrophilic polymers and their gels. XI. Microsyneresis in swollen poly(ethylene glycol methacrylate) gels induced by changes of temperature

Structure and properties of hydrophilic polymers and their gels. XII. Relaxation behaviour of the system poly(ethylene glycol monomethacrylate)-water below the glass transition temperature

Structure and properties of hydrophilic polymers and their gels. XII. Relaxation behaviour of the system poly(ethylene glycol monomethacrylate)-water below the glass transition temperature

On the structure and properties of hydrophilic polymers and their gels. XIII. Phase separation in the system poly(ethylene glycol monomethacrylate)-water at low temperatures

On the structure and properties of hydrophilic polymers and their gels. XIII. Phase separation in the system poly(ethylene glycol monomethacrylate)-water at low temperatures

Structure and properties of hydrophilic polymers and their gels. X. Gel filtration on ethyleneglycol methacrylate gels

Structure and properties of hydrophilic polymers and their gels. X. Gel filtration on ethyleneglycol methacrylate gels

Structure and properties of hydrophilic polymers and their gels. IX. The effect of water and low-molecular-weight compounds on the size and shape of the secondary loss maximum of hydrophilic esters of polymethacrylic acid

Structure and properties of hydrophilic polymers and their gels. IX. The effect of water and low-molecular-weight compounds on the size and shape of the secondary loss maximum of hydrophilic esters of polymethacrylic acid

Structure and properties of hydrophilic polymers and their gels. VII. Turbidity changes of polymeric gels poly(ethylene glycol methacrylate)-glycol-water

Structure and properties of hydrophilic polymers and their gels. VII. Turbidity changes of polymeric gels poly(ethylene glycol methacrylate)-glycol-water

Structure and properties of hydrophilic polymers and their gels. VIII. Optical characterization of turbid gels in changes of their volumes

Structure and properties of hydrophilic polymers and their gels. VIII. Optical characterization of turbid gels in changes of their volumes