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Electrospun nanofibrous membrane is an approved drug carrier. However, the radionuclide carrier used an electrospun membrane is rare. In this study, Poly(lactide-co-glycolide)(PLGA) nanofibrous nonwovens were prepared through electrospinning technology, and then surface modification of the nonwoven was performed to stably conjugate the radioisotope with the fibrous membrane. A novel PLGA nanofibrous...
The geometry and piezoelectric properties of chain in PVDF under different electric fields are studied by density functional theory (DFT). The simulation gives optimized geometry of PVDF of α chain and β chain, with rotation angle around ±50° and arbitrary angle between 175° and 185° respectively. The energy barrier is about 16.16 kJ/mol in the chain transition from α chain to β chain, and the one...
“Comb-like” graft copolymers, consisting of a poly((N-vinylcarbazole)-co-(4-vinylbenzyl chloride)) (P(NVK-co-VBC)) copolymer backbone from free radical polymerization and poly(((2-dimethylamino)ethyl methacrylate)-co-(tert-butyl acrylate)) (P(DMAEMA-co-tBA)) side chains from atom transfer radical polymerization (ATRP), were hydrolyzed to produce the acrylic acid (AAc)-containing “comb-like” graft...
This paper aims at elucidating some important parameters affecting the cellular morphology of poly(styrene-co-acrylonitrile) (SAN)/clay nanocomposite foams prepared with the supercritical CO 2 technology. Prior to foaming experiments, the SAN/CO 2 system has first been studied. The effect of nanoclay on CO 2 sorption/desorption rate into/from SAN is assessed with a gravimetric...
Depending on the nature and strength of interfacial interactions on the surface of nanoparticles, strong and unusual modifications to reinforcement and viscoelastic properties were observed for nanocomposites made of an elastomer with chain-end mussel-mimetic modification. Emulating 3,4-dihydroxyphenyl-l-alanine in marine mussel adhesive proteins, a styrene–butadiene random copolymer terminated with...
Nanodispersions of polyurethane components with a three dimensional gelled network of filler is formed by the addition of a very small quantity of vapor grown carbon nanofiber (CNF). Reactive foaming of these nanodispersions produced polyurethane foams with superior properties. The kinetic profiles of polymerization and foaming reactions are not affected by the addition of filler. The cellular structure...
Polyurethane based macrophotoinitiator (PU-PI) had been designed and synthesized, and applied to photoinitiated dispersion polymerization of methyl methacrylate as both photoinitiator and stabilizer, with ethanol/water mixture as reaction medium. Monomer conversion over 90% was achieved within 25 min of UV irradiation at room temperature, and monodisperse PMMA microspheres were obtained. The structure...
Polystyrene-clay nanocomposites were prepared by in situ polymerization to achieve the better dispersion of lamellar silicates i.e. montmorillonite and fluorohectorite and were used to process foams with supercritical CO 2 . Clay–Polymer interactions were modulated by varying the surface treatment of clays: a physical interface was formed with the compatible surfactant showing aromatic groups...
A linear amphiphilic multiblock copolymer (PNIPAm-PtBA-PNIPAm) m was successfully synthesized by a two-step reversible addition–fragmentation transfer (RAFT) polymerization in the presence of a cyclic trithiocarbonate as RAFT agent. The micelle behavior of (PNIPAm-PtBA-PNIPAm) m multiblock copolymer in aqueous solution was then investigated by means of normal TEM, cryo-TEM, static...
The efficacy with which a range of nanotubes could reinforce a high density polyethylene (HDPE) matrix was investigated, in relation to nanotube diameter, purity, functionalization, alignment and nanotube bulk density. Composites were prepared by melt blending multiwall carbon nanotubes (MWNTs) with high density polyethylene (HDPE), followed by the injection molding of tensile specimens. At a 5 wt%...
Chemical and physical properties of polymeric species in solution strongly depend on their structure, which can be modulated by covalently linking substituents of different solubility. In this work, the effect of changing the interaction strength and fractional loading of hydrophobic substituents on semi-flexible hydrophilic polymers of varying chain length is studied by means of Monte Carlo simulations...
A new type of multifunctional ammonium modifier with carbonyl group and vinyl group was synthesized to prepare multifunctional montmorillonites (F-MMTs), which were used as multifunctional catalyst supports for in situ ethylene polymerization. High loading of metallocene catalyst in the galleries of F-MMT had been achieved due to the presence of carbonyl group in the multifunctional modifier. XRD...
A novel type of amphiphilic diblock copolymer consisting of butyl methacrylate (BMA) block and glycidyl methacrylate (GMA) block (BG copolymer) was successfully synthesized via atom transfer radical polymerization (ATRP) and then utilized as a phase separator to control the porous structure of poly(butyl methacrylate-co-ethylene dimethacrylate) (poly(BMA-co-EDMA)) monoliths. It has been found that...
The effects of Li salts (Lithium tetrafluoroborate (Li[BF 4 ]) and Lithium bis(trifluoromethanesulfonyl)imide (Li[TFSI])) on the electrochemical and electromechanical properties of an actuator using a polymer-supported single-walled carbon nanotube (SWCNT)-ionic liquid (IL) gel electrode were investigated. The ionic conductivities of the gel electrolyte layers with molar ratios of Li[BF ...
The mechanism for the formation of amphiphilic core–shell particles in water is elucidated via a kinetic study of semi-batch polymerization of methyl methacrylate (MMA) grafted from polyethylenimine (PEI) initiated with tert-butyl hydroperoxide in an emulsion polymerization. The monomer conversion, the polymerization kinetics, the particle size, the particle number density, the poly(methyl methacrylate)...
The effects of polymerization time and temperature on the molecular weight and molecular weight distribution of polyethylene, produced over homogeneous catalyst bis[N-(3-tert-butyl salicylidene)anilinato]zirconium(IV) dichloride t Bu-L 2 ZrCl 2 /MAO have been studied. The data on the number of active centers (C P ) and propagation rate constants (k P ) at different...
The mechanical hysteresis and recovery behaviors of an elastomeric ethylene methacrylic acid butyl acrylate (EMAABA) copolymer, its sodium-neutralized (EMAABA Na ) and zinc-neutralized (EMAABA Zn ) counterparts are evaluated and compared under large strain loading conditions. Experiments at different rates, under cyclic loading conditions and in relaxation indicate two major hysteresis...
The adsorption behavior of several amphiphilic polyelectrolytes of poly(maleic anhydride-alt-styrene) functionalized with naphthyl and phenyl groups, onto amino-terminated silicon wafer has been studied by means of null- ellipsometry, atomic force microscopy (AFM) and contact angle measurements. The maximum of adsorption, Γ plateau , varies with the ionic strength, the polyelectrolyte structure...
Layer-aligned poly(vinyl alcohol)/graphene nanocomposites in the form of films are prepared by reducing graphite oxide in the polymer matrix in a simple solution processing. X-ray diffractions, scanning electron microscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis are used to study the structure and properties of these nanocomposites...
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