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The effect of solvation–desolvation process on the conformational change of poly(vinyl alcohol) in an extremely dilute aqueous solution during the repeated freezing–thawing treatment was investigated by a differential refractometer. It was found that the hydrodynamic volume of PVA decreased regularly and smoothly with the number of freezing–thawing cycles treatment increasing, as the intra-molecular...
The objective of this work is to provide some elements for developing a theoretical methodology aimed to describe the ion conductivity mechanism of chitosan membrane and to obtain its magnitude. Atomistic molecular modeling has been utilized to construct an ionic-conducting polymer–electrolyte system consisting of chitosan, H 2 O molecules and H 3 O + , OH − , SO42−...
The present study demonstrates the use of a simple and versatile melt-compounding route to prepare NaClO 4 -containing poly(ethylene oxide) PEO/clay nanocomposites combining excellent mechanical properties with a competitive level of the ionic conductivity. The nanostructure and the resulting thermal, mechanical and conductive properties of the salt-containing PEO/clay nanocomposites were...
Poly(ethylene terephthalate) (PET) (IV:0.15dL/g) oligomer was obtained by depolymerisation of high molecular weight PET. Polycarbonate (PC) oligomer (IV: 0.15dL/g) was synthesized by standard melt polymerization procedure using bisphenol A and diphenyl carbonate in the presence of a basic catalyst. Blends of varying compositions were prepared by melt blending the chemically distinct PET and PC oligomers...
By using thermal and NMR analyses with supporting evidence from X-ray and scanning electron and optical microscopy, this study has attempted to clarify confusing issues of physical miscibility vs. chemical trans-reaction in blends of aryl polyesters upon heating. The study demonstrated that the blends of poly(pentylene terephthalate) (PPT) with poly(ethylene naphthalate) (PEN) were initially immiscible;...
This paper presents a series of dendrimers via a convergent synthetic approach with three generations, which contain perylene diimide cores, Fréchet-type poly(aryl ether) dendrons, and carbazole (CZ) or oxadiazole (OXZ) peripheral functional groups. The higher generation dendrimer has an obvious site-isolation or dilution effect of dendrons, which results in a relatively small red-shift of absorption...
Near-infrared (NIR) reflection spectroscopy was used to monitor the conversion of double bonds in acrylate coatings after irradiation with UV light or electron beams. Quantitative analysis of the spectroscopic data was performed either with a chemometric method on the basis of the PLS algorithm or according to the Beer–Lambert law. FTIR spectroscopy was used for calibration. In-line monitoring of...
Hyperbranched polyglycidol (PG) was synthesized via a new polymerization pathway of glycidol using zinc glutarate (ZnGA) as a catalyst. ZnGA was found to be a highly active catalyst for the ring-opening polymerization of glycidol. The complex chemical structures of hyperbranched PG and its ketalized derivative (K-PG) were determined by specialized 13 C nuclear magnetic resonance spectroscopic...
We report an ATP fueled soft gel machine reconstructed from muscle proteins of actin and myosin. Chemically cross-linked actin gel filaments, several decade times the length of native actin filaments (F-actin) move along a chemically cross-linked myosin fibrous gel (1cm long and 50μm in diameter) with a velocity as high as that of native F-actin, by coupling to ATP hydrolysis. The motility observed...
The main aim of this work is to study the effective elastic modulus of hybrid composites through micromechanical modeling. The micromechanical framework based on the generalized method of cells has been employed for this study. The predictions based on the present model are compared with an assortment of experimental and other theoretical predictions. The effect of two types; sequential mode and mixed...
Three poly(styrene-b-ethylene-co-butylene-b-styrene) (SEBS) thermoplastic elastomers (TPEs) are studied mechanically and compared to cross-linked natural rubber. It is observed that subtle alterations in the mid-block of the TPEs affect their mechanical properties significantly. The stress relaxation at room temperature is significantly altered indicating a reduced flow in systems where the ratio...
Polyimide (PI)–carbon nanotubes composites were fabricated by in situ polymerization using multi wall carbon nanotubes (MWNT) as fillers. It suggested that in situ polymerization is an ideal technique to make a perfect dispersion of carbon nanotubes into matrixes. Besides it, the pre-treatment of carbon nanotubes in solvent to make the networks untied enough and to let solvent percolated into the...
The degradation pathway of ethylene–vinyl acetate copolymers and their nanocomposites is investigated using TGA/FT-IR, TGA, GC–MS, cone calorimetry and UV techniques to determine if the presence of the clay has an effect on the degradation pathway. The first step of the degradation, the loss of acetic acid by chain stripping, has been shown to be accelerated by the presence of clay. In this work we...
The synthesis and characterization of degradable polymeric networks for biomedical applications was performed. Cross-linked films of poly(ε-caprolactone) (PCL) and poly(1,5-dioxepan-2-one) (PDXO) having various mole fractions of monomers and different cross-link densities were successfully prepared using 2,2′-bis-(ε-caprolactone-4-yl) propane (BCP) as cross-linking agent. Reaction parameters were...
Polyether(ester–amide)s (PEEA) segmented block copolymers with di- and tri-functional poly(propylene oxide)s and amide segments were synthesized and the elastic properties studied. The difunctional polyether used had a molecular weight of 2300g/mol end capped with 20wt% ethylene oxide. The trifunctional polyether had a molecular weight of 6000g/mol of which each arm had a molecular weight of 2000g/mol...
To gain an insight into the effect of core-crosslinking on polyion complex (PIC) micelles, the properties of PIC micelles prepared by mixing model protein, chicken egg white lysozyme with the synthesized α-methoxy-poly(ethylene glycol)–poly(α,β-aspartic acid) block copolymer (PEG–P(Asp)–NH 2 ) followed by glutaraldehyde addition, were investigated in detail. The added glutaraldehyde interacted...
Na-Montmorillonite (Na-Mmt) was melt-intercalated with alkylamine and quarternized ammonium salts of sulfonated polystyrene ionomers (SPS) with no other organic modification. Mixtures of SPS and polystyrene (PS) also exhibited similar intercalation, indicating that the ionomer was an effective compatibilizer for a non-polar polymer such as PS. The materials were mixed in a co-rotating, non-intermeshing...
The regularity of ‘skin-core’ type of crystallinity distribution within the polyethylene cylindrical specimen crystallized under high pressure was investigated via modulated differential scanning calorimeter (MDSC), wide angle X-ray diffraction meter (WAXD), dynamic mechanical analyzer (DMA) and scanning electron microscope (SEM). The relationship between the gradient of high pressure stress field...
Because of its good chemical and thermal stability due to the π-delocalization along the polymer chain, poly(p-phenylene) was used as starting material for fluorination to obtain new carbon fluoride. A complete characterization of both the virgin polymer, in order to define parameters such as the chain length and the degree of crystallinity, and the fluorinated materials was performed by complementary...
A combined NMR and TOF-SIMS study has been carried out on 1H,1H,2H-perfluorododecene plasma polymers. Pulsed plasma polymerization is found to give rise to a high level of structural retention for the perfluoroalkyl groups, whereas continuous wave conditions lead to monomer fragmentation and cross linking. This investigation provides unequivocal proof that pulsed plasma deposition is a simple and...
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