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Synthesis and characterization of polyaniline-polyvinyl chloride blends doped with sulfamic acid in aqueous tetrahydrofuran

100%
Ameen S., Ali V., Zulfequar M., Mazharul Haq M., Husain M.
Open Chemistry
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2006
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vol. 4
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issue 4
565-577
EN
The temperature dependence of direct current (dc) conductivity was studied for various samples of polyaniline-polyvinylchloride (PANI-PVC) blended films. Polyaniline was doped with different concentrations of sulfamic acid in aqueous tetrahydrofuran (THF) and the blended films were prepared by varying the amount of doped PANI relative to a fixed amount of PVC. The dc conductivity of PANI-PVC blended films was measured to determine the effect of sulfamic acid (dopant) in the temperature range (300–400K). The mechanism of conduction is explained by a two-phase model. In order to evaluate the effect of the dopant, conductivity-derived parameters such as the pre-exponential factor (σ o) and the activation energy (ΔE) were calculated. The structural changes of polyaniline-PVC blended films were characterized by FTIR spectroscopy that explores information about the suitability of the dopant in the chemical doping process.
2
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VISCOMETRIC STUDIES OF MICROCRYSTALLINE CHITOSAN/POLY(VINYL ALCOHOL) MIXTURES

100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2011
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vol. 16
43 - 48
EN
In the present paper, the results of viscosity measurements in dilute solutions of microcrystalline chitosan (MCCh) with poly(vinyl alcohol) (PVA) of different degrees of hydrolysis are presented. Microcrystalline chitosan is blended with poly(vinyl alcohol) in aqueous 0.1 MCH3COOH/0.2 M NaCl. Viscosity measurements of dilute polymer solution were carried out in an Ubbelohde capillary viscometer. The final result depends on (I) the thermodynamic goodness of the solvent, on (II) the applied extrapolation method used for determination of the interaction parameters, on (III) the assumed miscibility criteria, on (IV) the degree of hydrolysis of PVA, and on (V) the blend composition.
3
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RHEOLOGICAL PROPERTIES OF CHITOSAN BLENDS WITH PARTIALLY HYDROLYZED POLYACRYLAMIDE IN DIFFERENT SOLVENTS

88%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2012
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vol. 17
53 - 62
EN
In the present paper, the results of rheological measurements in solutions of chitosan (Ch) with partially hydrolyzed polyacrylamide (HPAM) are presented. Aqueous acetic acid, lactic acid and aqueous acetic acid/NaCl were used as solvents for chitosan, HPAM and Ch/HPAM solution blends. The criterion of miscibility of solution blends, based on the additivity rule of apparent shear viscosity (ηa) has been discussed. The rheological parameters from power law (Ostwald de Waele model) and activation energy of viscous flow (Ea) have been calculated from the flow curves and Arrhenius plots, respectively. It was found that studied polymer solutions exhibited the non-Newtonian behaviour with shear-thinning and/or shear-thickening areas. The final result depends on the thermodynamic goodness of the solvent and on the blend composition.
4
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Mechanical and thermal properties of PP/PBT blends compatibilized with triblock thermoplastic elastomer

88%
Ignaczak W., Wiśniewska K., Janik J., Fray M. E.
Polish Journal of Chemical Technology
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2015
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vol. 17
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issue 3
78-83
EN
A linear triblock copolymer, poly(styrene-b-etylene/butylene-b-styrene)(SEBS) thermoplastic elastomer (TPE) grafted with maleic anhydride was used for compatibilization of PP/PBT blends. PP/PBT blends of different mass ratios 60/40, 50/50, 40/60 were mixed with 2.5, 5.0 and 7.5 wt.% of SEBS copolymer in a twin screw extruder. Differential scanning calorimetry and dynamic mechanical analysis were performed to define the phase structure of PP/PBT blends. TPE with a rubbery mid-block shifted the glass transition of PP/PBT blend towards lower temperatures, and significant decrease the crystallization temperature of a crystalline phase of PP component was observed. The influence of the amount of compatibilizer and the blend composition on the mechanical properties (tensile and flexural strengths, toughness and moduli) was determined. Addition of 5 wt.% of a triblock TPE led to a three-fold increase of PP/PBT toughness. A significant increase of impact properties was observed for all materials compatibilized with the highest amount of SEBS copolymer.
5
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THERMAL AND ATOMIC FORCE MICROSCOPY (AFM) STUDIES OF MICROCRYSTALLINE CHITOSAN/POLY(VINYL ALCOHOL) MIXTURES

88%
Lewandowska K.
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vol. 15
11 - 16
EN
In the present paper, the results of thermal analysis (DSC and TGA) and atomic force microscopy studies of microcrystalline chitosan (MCCh) with poly(vinyl alcohol) (PVA) are presented. Microcrystalline chitosan is blended with poly(vinyl alcohol) in acetic acid solution and this solution is cast to prepare the blend film. From thermal curves the thermal transitions: Tg, Tm and characteristic temperatures of decomposition: Tdi, Tmax have been determined and compared. The influence of the degree of PVA hydrolysis on the thermal properties of blend systems has been discussed. The surface properties of the MCCh and PVA films and their blends have been studied by tapping-mode atomic force microscopy (AFM). The changes of topography images were considered by determining the root mean square (RMS) deviation in the image data. The obtained results suggested that in solid MCCh/PVA mixtures the components are poorly miscible.
6
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CHARACTERISATION OF CHITOSAN/HYALURONIC ACID BLEND FILMS MODIFIED BY COLLAGEN

88%
Lewandowska K., Alina S., Grabska S., Michalska M.
Progress on Chemistry and Application of Chitin and its Derivatives
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2017
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vol. 22
125-134
EN
In the present study, thin films based on the blends of chitosan (Ch) and hyaluronic acid (HA) with and without collagen (Coll) were characterised using tensile tests, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermogravimetric analysis (TGA). Ch/HA and Ch/HA/Coll polymer blends were prepared using the solvent evaporation technique. The interactions between polymer components in the binary and ternary blends were studied by FTIR analysis. Mechanical properties were studied and compared with those of simple polymer films. These results show that the addition of collagen into Ch/HA blends led to the increase of tensile strength and Young modulus. Moreover, it was found that the thermal stability of the Ch/HA binary blend significantly increased upon the addition of collagen.
7
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INFLUENCE OF THE INTERMOLECULAR INTERACTION ON PHYSICO-CHEMICAL PROPERTIES OF CHITOSAN/HYALURONIC ACID BLENDS

88%
Lewandowska K., Alina S., Grabska S.
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EN
In the present study, the results of viscosity measurements in dilute solutions of chitosan (Ch) with hyaluronic acid (HA) are presented. Chitosan is blended with hyaluronic acid in aqueous 0.1M CH3COOH/0.2M NaCl and 0.3M NaCl respectively, or with the addition of HEPES. Viscosity measurements of dilute polymer solution were carried out in an Ubbelohde capillary viscometer. The intrinsic viscosity, [], and the viscosity interaction parameters, bm, have been determined for the binary (solvent/polymer) and ternary (solvent/polymer A/polymer B) systems. The homogeneity and morphology of chitosan blends were ascertained from the tapping-mode atomic force microscopy. The surface roughness of chitosan, hyaluronic acid and Ch/HA blended films was altered by mixing. The obtained results suggested that there was existence of the strong interactions between chitosan and hyaluronic acid.
8
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THE INFLUENCE OF THE TYPE SOLVENT ON THE STRUCTURE OF CHITOSAN BLENDS WITH HYALURONIC ACID

88%
Lewandowska K., Sionkowska A., Grabska S.
Progress on Chemistry and Application of Chitin and its Derivatives
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2016
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vol. 21
147-153
EN
The influence of the type solvent on the structure of chitosan, hyaluronic acid and their blend films was investigated. Aqueous acetic acid, hydrochloric acid, sodium chloride and aqueous acetic acid/NaCl were used as solvents for chitosan, hyaluronic acid and Ch/HA solution blends. Ch, HA and their blend films were prepared by casting technique. The homogeneity and morphology of chitosan blends were ascertained from the tapping-mode atomic force microscopy (AFM) and scanning electron microscopy (SEM). The changes of topography images are considered by determining the root mean square (RMS, Rq) deviation in the image data. The surface roughness of chitosan, hyaluronic acid and Ch/HA blended films was altered by mixing. The structure of chitosan blends with hyaluronic acid depends on the blend composition and on the solvent used for preparing the blend.
9
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VISCOMETRIC STUDIES OF CHITOSAN/POLYACRYLAMIDE MIXTURES

88%
Lewandowska K., Sionkowska A., Krasińska K.
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2014
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vol. 19
73-78
EN
Polymer-polymer interactions and miscibility for chitosan (Ch) and partially hydrolysed polyacrylamide (HPAM) have been investigated using dilute solution viscosity. The intrinsic viscosity, [η], and the viscosity interaction parameters, bm, have been determined for the binary (solvent/polymer) and ternary (solvent/polymer A/polymer B) systems. Degree of miscibility of these polymer mixtures was estimated on the basis of two criteria. The final result depends on (i) the applied extrapolation method used for determination of the interaction parameters, (ii) the assumed miscibility criteria, and (iii) the blend composition.
10
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RHEOLOGICAL AND MECHANICAL STUDIES OF CHITOSAN BLENDS WITH THE ADDITION OF AN IONIC LIQUID

75%
Lewandowska K., Szulc M.
Progress on Chemistry and Application of Chitin and its Derivatives
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2019
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vol. 24
119 - 126
EN
In the present paper, results from rheological measurements and tensile tests of polymer blends containing chitosan and poly(vinyl alcohol) with different additions of an ionic liquid are presented. Flow measurements were carried out using solutions of pure polymers and their blends with and without the addition of an ionic liquid. It has been observed that the polymer solutions and their blends exhibited non-Newtonian behaviour. Rheological parameters from the power law and activation energy of viscous flow were determined and discussed. Mechanical properties, such as the tensile strength and ultimate percentage of elongation of films, have been determined and compared. This study thus shows that the addition of an ionic liquid is an effective method for improving the flexibility of chitosan blends.
11
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MISCIBILITY AND INTERACTIONS IN CHITOSAN AND POLYACRYLAMIDE MIXTURES

75%
Lewandowska K.
|
2014
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vol. 19
65-71
EN
In the present work, the results of Fourier transform infrared (FTIR) and atomic force microscopy (AFM) studies of films of chitosan acetate (ChA), polyacrylamide (PAM), and their mixtures are presented. The morphology of the ChA and PAM films and their mixtures was studied by tappingmode atomic force microscopy (AFM). The topography images were considered by determining the root mean square (RMS) deviation in the image data. The study of mixtures by AFM showed a completely different morphology when compared with pure components. The roughness of mixtures increases with the increase of ChA content but is significantly reduced after UV exposure. This may indicate a strong interaction between the polymeric components. The FTIR spectroscopy also supports the obtained results. The miscibility of polymer mixtures is related to interactions between the functional groups of the polymeric components.
12
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SURFACE PROPERTIES OF CHITOSAN ACETATE, POLYACRYLAMIDE AND THEIR MIXTURES

75%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2013
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vol. 18
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issue 18
29-34
EN
The surface properties of chitosan acetate (ChA), polyacrylamide (PAM) and ChA/PAM mixtures have been investigated by the tapping-mode atomic force microscopy (AFM) and monitored by contact angle measurements. Chitosan is blended with polyacrylamide in acetic acid solution and this solution is cast to prepare the mixture film. Measurements of the contact angle for two different liquids (diiodomethane and glycerol) on the surface of chitosan acetate. The surface free energy (γs) as well as dispersive (gsd) and polar (gsp) components were calculated from contact angle values by Owens-Wendt methods using an appropriate computer program. The values of polar and dispersive components of surface free energy show that PAM films are more polar than chitosan acetate films. In the case of ChA/PAM mixtures, the values of surface free energy and polar component are reduced significantly compared with pure polymers. This behavior indicates rather hydrophobic character of this surface. The changes of topography images were considered by determining the root mean square (RMS) deviation in the image data. The study of blends by AFM showed a completely different morphology when compared with pure components. The roughness of blends increases with the increase of ChA content. This may indicates a strong interaction between the polymeric components.
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