Glass polyalkenoate dental cements based on physical blends of poly(acrylic acid) and poly(vinyl phosphonic acid)

Physical blends of spray-dried poly(acrylic acid), PAA, with poly(vinyl phosphonic acid), PVPA, have been prepared and used in experimental dental cements by mixing them with basic sub-45 μm acid-degradable fluoroaluminosilicate glass powders and adding water. The effect of varying the ratio of PAA to PVPA, of altering the molar mass of PAA, and of using glasses of differing basicity have been investigated. The compressive strengths of the best of the cements formed from these blends were comparable to those formed from the individual polyacids, i.e. about 160 MPa.     

Thermal behavior of poly(acrylic acid)–poly(vinyl pyrrolidone) and poly(acrylic acid)–metal–poly(vinyl pyrrolidone) complexes

Thermal analysis (TGA and DTA) of samples of PAA, PVP, PAA–PVP complexes, containing different weight fractions of PAA and ternary polymer–metal–polymer complexes, were studied. The activation energy parameters for the thermal degradation were also calculated. The study of the effect of FeCl₃, NiCl₂, and Ni(NO₃)₂ on the TGA and DTA curves of the complexes showed that the decompositions are dependent on the concentrations and the nature of the metal ions. The DTA traces of PAA–PVP complex containing FeCl₃, NiCl₂, and Ni(NO₃)₂ showed that the treatment of the complex with these metal ions causes considerable changes in the thermal decomposition of PAA–PVP complex. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4049–4057, 2006     

Energy transfer to Eu(III) in the solid‐state low‐density polyethylene–poly(acrylic acid) and low‐density polyethylene–Fe2O3–poly(acrylic acid) matrices

Ion exchange between H⁺ and Eu³⁺ and/or Tb³⁺ was studied in the material modified by in situ sorption and thermal polymerization of acrylic acid in low‐density polyethylene (LDPE–PAA) and in the composite system LDPE–Fe₂O₃–PAA. Fluorescence spectroscopy showed evidence of Eu³⁺ and/or Tb³⁺ ion exchanges in these materials. The matrix LDPE–PAA after Eu(III) ion exchange presented luminescence (excitation 265 nm). This was explained by an energy‐transfer process from the matrix LDPE–PAA to Eu³⁺ ions. The LDPE–PAA matrix after simultaneous Eu³⁺/Tb³⁺ ion exchange exhibited Eu³⁺ and Tb³⁺ ion luminescence (excitation 265 nm), confirming an energy‐transfer process from LDPE–PAA to Eu³⁺ ions in LDPE–PAA–Eu³⁺–Tb³⁺ matrix. Fe₂O₃ in LDPE–Fe₂O₃–PAA quenched the matrix for excitation at 265 nm and no emission at the region 400 nm was observed. The luminescence of Tb³⁺ ions in the matrix LDPE–Fe₂O₃–PAA–Tb³⁺ (excitation 265 nm) was partially quenched by Fe₂O₃. However, a weak emission of Eu³⁺ ions was observed (excitation 265 nm) in the matrix LDPE–Fe₂O₃–PAA after simultaneous Eu³⁺ and Tb³⁺ ion exchanges, suggesting an energy transfer from Tb³⁺ to Eu³⁺ ions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 919–931, 2000     

Study of the interaction of poly(acrylic acid) and poly(acrylic acid‐poly acrylamide) complex with bone powders and hydroxyapatite by using TGA and DSC

The thermo gravimetric analysis (TGA) and differential scanning calorimetric analysis (DSC) were used to study the thermal degradation of poly(acrylic acid) PAA and poly(acrylamide) PAAm as well as the compound obtained from their interactions. The examination of the thermal curves revealed that the characteristics of the curves of the compound resulting from the cooperative interactions are different from those of the constituent polymers. The differences in the characteristics of the thermal curves were attributed to the formation of an interpolymer complex resulting from the interaction of PAA with PAAm at low pH value. These two thermal techniques were also used to investigate the thermal behavior of the compounds obtained from the interaction of PAA and (PAA‐PAAm) mixture with bone powders (BP) and hydroxyapatite (HA). It was found that the TGA, DTG, and DSC curves do not show the peak of formation and degradation of PAA anhydride which provided strong evidence for the consumption of PAA in the reaction between the polymer and BP. The interaction between PAA and the thermally treated BPs and HA was investigated. Moreover the interaction between the mixture of PAA and PAAm at different pH values and the BPs and HA was discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Bioartificial materials based on blends of collagen and poly(acrylic acid)

The interactions between soluble collagen (C) from calf skin and poly(acrylic acid) (PAA) were studied. Mixing aqueous solutions of collagen and PAA, at various pH values (2.5–4), leads to the formation of complexes that precipitate in the form of insoluble aggregates. The effects of mixture composition, pH, and ionic strength on C/PAA complex formation were investigated by gravimetric, turbidimetric, and conductometric analysis. The experimental results indicate that the complexes form through electrostatic interactions. Homogeneous solid films with variable C/PAA ratios were obtained by casting from solutions in which the pH was adjusted just over the isoelectric point of collagen, thus avoiding the attractive ionic interactions responsible for the complexation of collagen and PAA molecules. A relevant result obtained is related to the possibility of restoring the ionic interactions between the two polymers inside the solid films. Mixture composition and pH appear to influence the thermal properties of both complexes and films. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 971–976, 1999     

A supramolecular structured complex of poly(acrylic acid) and polystyrene‐block‐poly(vinylbenzyltrimethylammonium chloride)

Complexation of poly(acrylic acid) (PAA) by polystyrene‐block‐poly(vinylbenzyltrimethylammonium chloride) (PS‐b‐VB) results in a mesomorphously ordered material with a glass transition temperature of 71 °C. The complex is assumed to consist of hexagonally‐ordered ion‐rich cylindrical rods containing the PAA embedded in a polystyrene matrix. It has been shown by small‐angle X‐ray scattering (SAXS) analysis that the mesophase is characterized by sharp phase boundaries between ionic and non‐ionic regions. The structure parameters are evaluated by using a two‐dimensional interface distribution function resulting in an average cylinder radius in the range 3.0–3.5 nm and a lattice constant of 14 nm. The radius distribution is calculated to be relatively broad, which is found to be consistant with sharp phase boundaries. PS‐b‐VB‐PAA represents an example of a new type of polymeric hybrid material with a supramolecular ordered ionic–non‐ionic nanostructure. © 2000 Society of Chemical Industry     

Synthesis and characterization of fluorocarbon‐containing,hydrophobically associative poly(acrylic acid‐co‐Rf‐poly(ethylene glycol) macromonomer)

Fluorocarbon‐ or hydrocarbon‐end‐capped poly(ethylene glycol) (PEG) macromonomers were prepared with coupling methods. Several factors affecting the synthesis were studied, and the optimal condition was ascertained. The critical micelle concentrations of these macromonomers were determined with the fluorescence method. Novel fluorocarbon‐containing, hydrophobically modified, alkali‐soluble copolymers were made by the copolymerization of fluorocarbon‐ or hydrocarbon‐alkyl‐end‐capped PEG macromonomers with acrylic acid in an organic solvent. The effects of the macromonomer contents, polymerization conditions, spacer, temperature, shear rate, pH, and addition of salt and various surfactants on the solution viscosity were preliminarily investigated. A very strong hydrophobic association was found for these copolymer solutions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1035–1047, 2002; DOI 10.1002/app.10393     

Electrically conducting polyaniline–poly(acrylic acid) blends

We report an electrically conducting polyaniline–poly(acrylic acid) blend coatings prepared by mixing the emeraldine base (EB) form of polyaniline (PANI) and poly(acrylic acid) (PAA) aqueous solution. The samples show a moderate electrical conductivity σ. If they are immersed in an HCl aqueous solution, the conductivity of the samples is increased by two or three orders of magnitude and their thermal stability is also improved. Optical transmittance spectra show a complete protonation of PANI–PAA blends after immersion in HCl aqueous solution. Fourier transform infrared spectroscopy studies indicate that the better thermal stability of σ could come from the more stable protonated imine nitrogen ions. A low percolation threshold phenomenon is observed in PANI–PAA blends, from a strong interaction between the carboxylic acid groups of PAA and the nitrogen atoms of PANI. © 1998 SCI.     

Dextran/poly(acrylic acid) mixtures as miscible blends

Bioartificial polymeric materials based on blends of dextran and poly(acrylic acid) were prepared in form of films and characterized in order to evaluate the miscibility of the natural component with the synthetic one. Films with different composition ratios were prepared by solution casting and analyzed by dynamic mechanical-thermal analysis, differential scanning calorimetry, and scanning electron microscopy. The obtained results indicate that dextran is miscible with poly(acrylic acid). The miscibility was mainly ascertained on the bases of the occurrence of a single composition-dependent glass transition temperature in each blend and also on the bases of the transparency and homogeneity of the films. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2089–2094, 1997     

Surface modification of ultra‐flat polydimethylsiloxane by UV‐grafted poly(acrylic acid) brushes

The graft density and surface topography of ultra‐flat polydimethylsiloxan films grafted with poly(acrylic acid) brushes by UV irradiation are investigated. The graft density keeps increase with the irradiation time and with the monomer concentration to a maximum, after which it remains unchanged in the former case or drops in the latter. Atomic force microscopy results show that a longer irradiation time, a higher monomer concentration and the addition of ethanol in the grafting solution are favorable to obtain the grafted polydimethylsiloxan films with flat surface. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The intrinsic viscosity of poly(acrylic acid) and partially neutralized poly(acrylic acid) by isoionic dilution

The isoionic dilution method has been used to measure the intrinsic viscosity, [η], of a poly(acrylic acid) (PAA) sample as a function of neutralization degree, i, at low ionic strength, I = 1.0 × 10. The results obtained for the counterion activity are in close agreement with Manning's theory for counterion condensation. The influence of the ionic strength, I, on [η] and on the Huggins coefficient, k', was also examined and the exponents of the scaling laws relating these two parameters with I were found.     

Characterization of polyelectrolyte effect in poly(acrylic acid) solutions

The viscometric behavior of poly(acrylic acid) solutions, as well as their ion transport properties, were monitored as a function of polymer concentration and the addition of KOH in nonisoionic conditions. Polyelectrolyte effect was studied and characterized by conductivimetry as well as viscometric properties at the infinite dilution limit. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 191–196, 2003     

Interpolymer complexes of poly(acrylamide) and poly(N-isopropylacrylamide) with poly(acrylic acid): a comparative study

The interpolymer complexation, through successive hydrogen bonding, between poly(acrylamide) (PAAm) and poly(N-isopropylacrylamide) (PNiPAAm) with poly(acrylic acid) (PAA) in aqueous solution has been viscometrically and potentiometrically investigated. The stoichiometry of the complexes formed was determined. By comparing the strength of the two complexes the very important contribution of the hydrophobic interaction in their formation has been indicated.     

Poly(acrylic acid)–poly(vinyl alcohol) copolymers with superabsorbent properties

Biodegradable polyacrylates were produced by a series of novel copolymerization and/or crosslinking techniques using poly(vinyl alcohol) (PVA) moieties modified by the incorporation of olefinic structures. PVA was modified by a tosylation and/or detosylation reaction. The functionalized PVA was copolymerized and/or crosslinked with acrylic acid or its partially neutralized form to give crosslinked polyacrylates that could swell in water. Their swelling behavior was determined under load. Degradation studies were performed in α-chymotrypsin, trypsin, and papain solutions. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 817–829, 1998     

Calcium ion‐induced self‐healing pattern of chemically crosslinked poly(acrylic acid) hydrogels

Poly(acrylic acid) hydrogels crosslinked with N,N′‐methylenebisacrylamide were synthesized by free radical polymerization. Polymerization conditions had a significant influence over the gel content and swelling behaviour of the hydrogels. The incorporation of calcium ions led to the origin of a self‐healing feature. The self‐healing behaviour and mechanical performance of the hydrogels were systematically investigated. The hydrogels showed good tensile strength of 1 MPa and excellent stretchable behaviour where hydrogels regained instantaneously. Hydrogel pieces joined together to become an integrated matrix as soon as two cut pieces were brought in contact. The hydrogels possessed a marked healing efficiency of 97% within 6 h at room temperature without any external intervention. The results are explained in terms of the dynamic mobility of calcium ions within the dual‐crosslinked networks of the poly(acrylic acid) hydrogels. © 2017 Society of Chemical Industry     

Enhanced oxygen‐barrier and water‐resistance properties of poly(vinyl alcohol) blended with poly(acrylic acid) for packaging applications

To enhance the oxygen‐barrier and water‐resistance properties of poly(vinyl alcohol) (PVA) and expand its food packaging applicability, five crosslinked poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) blend films were prepared via esterification reactions between hydroxyl groups in PVA and carboxylic acid groups in PAA. The physical characteristics of the blends, including the thermal, barrier, mechanical and optical properties, were investigated as a function of PAA ratio. With increasing PAA content, the crosslinking density was significantly increased, resulting in changes in the chemical structure, morphology and crystallinity of the films. The oxygen transmission rate of pure PVA decreased from 5.91 to 1.59 cc m^?1 day^?1 with increasing PAA ratio. The water resistance, too, increased remarkably. All the blend films showed good optical transparency. The physical properties of the blend films were strongly correlated with the chemical structure and morphology changes, which varied with the PAA content. © 2016 Society of Chemical Industry     

A study on solution properties of poly(N,N‐diethylacrylamide‐co‐acrylic acid)

Poly(N,N‐diethylacrylamide) (PDEA), poly(acrylic acid) (PAA), and a series of (N,N‐diethylacrylamide‐co‐acrylic acid) (DEA‐AA) random copolymers were synthesized by the method of radical polymerization. The measurement of turbidity showed that the phase behaviors of the brine solutions of the copolymers changed dramatically with the mole fraction of DEA (x) in these copolymers. Copolymers cop6 (x = 0.06) and cop11 (x = 0.11) in which acrylic acid content was higher presented the upper critical solution temperature (UCST) phase behaviors similar to PAA. Copolymer cop27 (x = 0.27) presented the lower critical solution temperature (LCST) behavior similar to PDEA. While copolymer cop18 (x = 0.18) in which acrylic acid content was moderate presented both UCST and LCST behaviors. The solution properties of the polymers were investigated by measurements of viscosity, fluorescence, and pH. It is reasonable to suggest that the sharp change of the phase behavior may be attributed to the interaction between acrylamide group and carboxylic group in the (DEA‐AA) copolymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Complexation between poly(methacrylic acid) and poly(vinylpyrrolidone)

The complexation between poly(methacrylic acid) (PMAA) and poly(vinylpyrrolidone) (PVP) in aqueous phase was studied by various fluorescence techniques, including fluorescence anisotropy measurements, fluorescence probe studies, and nonradiation energy transfer. It was demonstrated that the complexation of PMAA with PVP occurs within a pH range of 1 to 5 and along with complexation, the conformation of PMAA changed from a hypercoiled to a loosely coiled form. The complex ratio between the two polymers is 2:1 (PMAA/PVP, in monomer unit). Salt effect studies showed that the complexation occurred due to formation of hydrogen bonds between the two polymers. Based on these conclusions and the “connected cluster model” for PMAA at low pH, a “ladder with connected cluster” model was proposed for the structure of PMAA/PVP complex formed at low pH. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 620–627, 2001     

Thermal properties of poly(maleic anhydride‐alt‐acrylic acid) in the presence of certain metal chlorides

Polychelates were synthesized by the addition of aqueous solutions of copper(II), cadmium(II), and nickel(II) chlorides to aqueous solutions of poly(maleic anhydride‐alt‐acrylic acid) [poly(MA‐alt‐AA)] in different pH media. The thermal properties of poly(MA‐alt‐AA) and its metal complexes were investigated with thermogravimetry and differential scanning calorimetry (DSC) measurements. The polychelates showed higher thermal stability than poly(MA‐alt‐AA). The thermogravimetry of the polymer–metal complexes revealed variations of the thermal stability by complexation with metal ions. The relative thermal stabilities of the systems under investigation were as follows: poly(MA‐alt‐AA)–Cd(II) > poly(MA‐alt‐AA)–Cu(II) > poly(MA‐alt‐AA)–Ni(II) > poly(MA‐alt‐AA). The effects of pH on the complexation and gravimetric analysis of the polychelates were also studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3926–3930, 2006     

XPS studies of poly(acrylic acid) grafted onto UV photo-oxidized polystyrene surfaces

UV photo-oxidation of polystyrene was achieved with 253.7 and 253.7/184.9?nm radiation in the presence of an atmospheric pressure of oxygen and analyzed by X-ray photoelectron spectroscopy as a function of treatment time. A methodical increase in the atomic percentage (at.%) of oxygen occurred during 253.7?nm activation up to 2?h of treatment time. Photo-oxidation with the 253.7/184.9?nm lamps resulted in a saturation level of ca. 35 at.% O. Initially, C–O and C=O groups were formed and then O–C=O type moieties. Poly(acrylic acid) was partially and/or thinly grafted onto the oxidized polystyrene surfaces.