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.
Carbon nanotubes (CNTs) have been dispersed within polypropylene with the purpose to prepare electromagnetic interference (EMI) absorbers. In order to limit the reflectivity of the electromagnetic waves at the interface of the materials while achieving good absorbing properties, the CNTs concentration must be kept low (<3 wt%) which means that a perfect dispersion must be ensured. Since CNTs do...
Reversible addition-fragmentation chain transfer (RAFT) cryopolymerizations of acrylamides and acrylates were successfully carried out at −5°C with cumene hydroperoxide/ascorbic acid as redox initiation couple and 2-dodecylsulfanyl- thiocarbonylsulfanyl-2-methylpropinoic acid as chain transfer agent. The cryopolymerization features of N,N-dimethylacrylamide (DMA) and tert-butyl acrylate (tBA) were...
Main chain bile acid polymers obtained via entropy-driven ring-opening metathesis are biodegradable polymers with excellent shape memory properties. X-ray scattering was used to study the conformational changes implicated in the shape memory effect of these polymers. Strain induced orientation and ordering was observed upon the drawing of the polymer films. A correlation between ordering and the shape...
Design, synthesis, and properties of a novel donor-acceptor-donor type low-voltage-driven green polymeric electrochrome, P1, which is based on 8-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-11-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)acenaphtho[1,2-b]quinoxaline (1) are highlighted. It is noted that P1 has an ambipolar (n- and p-doping processes) character in 0.1M tetrabutylammonium hexafluorophosphate/dichloromethane...
In order to investigate the rule of network evolvement during vulcanization of diene rubber, generally used diene rubbers, including natural rubber (NR), polybutadiene rubber (BR), and styrene butadiene rubber (SBR), were cured with the same curing agents but at different time. The cured rubbers were then analyzed with Rubber Process Analyzer (RPA2000), dissolution/swell, and Magnetic Resonance Crosslink...
Poly(dimethylsiloxane) (PDMS) cross-linked films with different concentrations of micrometer-sized garnet particles were prepared through hydrosilylation reaction between a di-vinyl-terminated PDMS and a four-functional silane cross-linker in the presence of a Platinum catalyst. The garnet particles, consisting of micrometer-sized Ce doped Y 3 Al 5 O 12 particles commonly used...
In this paper, a series of pyridine containing supramolecular polyurethanes (PUPys) were synthesized from BINA, HDI and BDO. Then the structure, morphology and thermal-induced shape memory effect (SMEs) of PUPys were investigated systematically. Results show that strong hydrogen bonding is formed in the urethane group as well as in the pyridine ring; and phase separation consisting of soft phase and...
Novel macro and meso porous polysulfone materials were prepared from miscible blends of polysulfones with a phenylindane containing polyimide by selective chemical decomposition of the polyimide phase using a dilute hydrazine or tetraammonium hydroxide solution in methanol. It was found that the pore size of the material is affected by the backbone structure of the polysulfone selected. The compatibility...
We can define structural indices of polymer or biopolymer complex structures and use them in the prediction of new drug targets in parasites. For instance, Plasmodium falciparum causes the most severe form of Malaria and kills up to 2.7 million people annually whereas Plasmodium vivax is geographically the most widely distributed cause with more than 80 million clinical cases. Due to drug resistance...
Polymeric lithium salts of sulfonated polysulfone (SPSU(X)Li) were synthesized via post sulfonation route followed by ion exchange. A novel single ion conducting solid polymer electrolyte (SPE) was prepared by curing poly(ethylene glycol)diglycidyl ether (PEGDGE) with 4,4′ diaminodiphenyl sulfone (DDS) in SPSU(X)Li matrix. The ionic conductivity, thermal stability and tensile properties were investigated...
Molecular dynamics simulations are performed to study the diffusion and permeation of gases, including argon, nitrogen, methane, carbon dioxide, and propane, in polystyrene over a wide range of temperatures. A jumping mechanism is observed for the diffusion of diffusants in polymer. The calculated diffusion coefficients agree well with the experimental data and with the results of former simulation...
Amphiphilic polymer conetworks (APCN) combine the properties of different polymers on the nanoscale affording advanced materials with unique properties. Here, we present the first APCN with a chiral hydrophilic phase. The conetworks were prepared by copolymerizing the tailored chiral monomer (R)-N-(1-hydroxybutan-2-yl)acrylamide (R-HBA) with two different crosslinkers that consist of bitelechelic...
A novel series of phthalazinone-based poly(arylene ether nitrile)s bearing terminal cyano groups via N–C linkages (PPEN-DCs) were synthesized by a simple solution polycondensation of 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (HPPZ) with calculated 2,6-difluorobenzonitrile (DFBN), followed by the termination of 4-chlorobenzonitrile (CBN). The M n s of oligomeric PPEN-DCs, which are in the range...
The anionic homopolymerization of DGEBA epoxy resin and its anionic copolymerization with a bislactone was studied using two alternative tertiary amines, 1-methylimidazole (1MI) and dimethylaminopyridine (DMAP) as initiators. 1MI caused slower cure than DMAP in neat DGEBA and DGEBA-bislactone formulations. Studies of the influence of the hydroxyl concentration in the DGEBA oligomer on its homopolymerization...
The molecular and electronic structure of all-thiophene dendrimers in both the neutral and oxidized states have been investigated performing quantum mechanical calculations on systems of up to 30 rings. Results evidenced that the repulsive steric interactions between the neighboring thiophene rings induce significant distortions from the planarity independently of the electronic state. On the other...
Hyperbranched poly(2-((bromobutyryl)oxy)ethyl acrylate) (HPBBEA) was grafted onto the exterior surface of mesoporous silica nanoparticles (MSNs) by surface-initiated self-condensing atom transfer radical vinyl polymerization (SCATRVP). The MSNs with ATRP initiator anchored on the exterior surface (MSN-Br) were prepared by the reaction of 5,6-dihydroxyhexyl-functionalized MSNs (MSN-OH) with α-bromoisobutyryl...
A comprehensive model for the stable jet region in electrospinning of crystallizing polymer melts has been presented. First, the conventional flow-induced crystallization (FIC) model by Ziabicki was coupled with the non-isothermal melt electrospinning model. The modeled initial jet profiles were compared to digitized experimental images of the stable Nylon-6 melt jet near the spinneret. The final...
An unconditionally stable upwinding scheme was proposed to improve the efficiency of the viscoelastic simulation in molding of optical products using a CV/FEM/FDM technique. A significant computation time saving was achieved due to an elimination of subdivision of the time step as required in the conventional numerical scheme. The approach was applied to simulate the flow-induced birefringence and...
MMA (methyl methacrylate) was polymerized in different ATRP systems using the different ligands of HMTETA (1, 1, 4, 7, 10, 10, hexamethyltriethylenetetraamine), TMEDA (N,N,N′,N′-Tetramethylethylenediamine) with copper salts (CuBr/CuBr 2 ) and EBriB was used as an initiator in toluene at a reaction temperature of 80°C. Both conventional and a low catalyst to initiator ratios ranging from 1/1...
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.