The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The adhesion between two immiscible polymers stitched together via mobile chains is studied with large scale molecular simulations employing a coarse-grained bead-spring model. An adhesion model is presented that incorporates both connector molecular slipping out viscously and bulk dissipation in two dissimilar glassy polymers, in which one is dense melt and another is loose. The contributions to...
A liquid-like phase, which cannot be assigned to water, has been observed in dry aspen wood using proton Nuclear Magnetic Resonance (NMR). This phase appears at approximately 45 °C as the temperature of the wood sample is increased from room temperature. As the free induction decay signal of the protons associated with this phase has a spin–spin relaxation time similar to that of water, bound to the...
Polystyrene and poly(methyl methacrylate/styrene) were prepared by in situ polymerization in the presence of Cloisite 20A, and were then used to synthesize unsaturated polyester-based thermoplastic/thermoset hybrids with improved properties. This approach allows for an increased degree of dispersion and delamination of the silicate layers as well as the presence of thermoplastic chains within the...
The deformation and fracture mechanisms of voided polymers and rubber-toughened polymers are an active research area where accurate fracture models still need to be proposed. The reason for the lack of accurate models stems from a lack of controlled experiments at the microscale, the scale of voids and cracks forming in polymers. In this paper, controlled experiments were carried out on thin polycarbonate...
The synthesis via anionic polymerization of six linear triblock terpolymers with various sequences of blocks such as PS (polystyrene), PB [poly(butadiene)], PI [(poly(isoprene)] and PCHD [poly(1,3-cyclohexadiene)] is reported. The synthesis of the terpolymers was carried out by the use of anionic polymerization with high-vacuum techniques and sequential monomer addition. Molecular characterization...
The lateral habit, unit cell structure and melting behaviour of single crystals of poly(ε-caprolactone) (PCL) prepared by the rapid expansion of a supercritical solution technique was studied by AFM at ambient and higher temperatures and by grazing-incident X-ray scattering using a synchrotron source. After dissolving PCL in a solution of supercritical CO 2 and 0.1 vol.% chloroform, an extremely...
The slide-ring (SR) gels derived from polyethylene glycol (PEG) threatened with polyrotaxane or hydroxypropyl polyrotaxane and crosslinked by 1,4-butanediol diglycidil ether were swollen with ionic liquids (ILs) and their ionic conduction was investigated. The molar conductivity of an SR gel swollen with 1-ethyl-3-methylimidazolium ethylsulfate (EMIES) with a high swelling ratio and with a small crosslinking...
Numerical simulations and algorithms are developed to analyze the dynamics of the ellipsoidal-like particles in a three-dimensional spatial frame. In particular we study in this case of an open channel pore for which we calculate the PDF distributions in the bulk and in the depletion layer next to a solid boundary. We develop a theoretical model based in this case on the equations of Jeffrey for the...
In this study, multiscale homogenization modeling to characterize the thermal conductivity of polymer nanocomposites is proposed to account for the Kapitza thermal resistance at the interface and the polymer immobilized interphase. Molecular dynamics simulations revealed that the thermal conductivity dependent on the embedded particle size originated from the structurally altered interphase zone of...
The possibility of applying Kissinger-type equations for the evaluation of apparent activation energy in the case of the glass transition phenomenon was investigated. Theoretically simulated data based on the generally accepted Tool–Narayanaswamy–Moynihan model were used to represent all possible cases of structural relaxation behavior. The values of apparent activation energy determined by Kissinger-type...
Nanocomposites made of a crosslinked polydimethylsiloxane matrix filled with silica beads were prepared by solvent-casting. The nanoparticle dispersion was tuned by changing the solvent. Three types of surface properties are investigated for the nanoparticles through surface grafting. Hydrophilic (unmodified), hydrophobic or carboxylic acid functionalized (allowing particle-PDMS covalent bonding)...
Instead of using free energy, we directly balanced confinement and hydrodynamic forces (f c = k B T/ξ and f h = 3πηul e ) on individual “blobs” to obtain a unified description of how polymer chains with different topologies (linear, star and branched) pass through a cylindrical pore with a diameter of D, much smaller than its size, under a flow rate (q), where k ...
A polymacromonomer consisting of polybutadiene backbone and polystyrene side chains (BS-PM) with the degree of polymerization of side chain n = 20 was synthesized by anionic polymerization. Five samples with different molecular weight or main-chain length were prepared. Light scattering and viscosity measurements were taken on dilute solutions of these BS-PM samples in toluene at 15.0 °C and in cyclohexane...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.