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Triblock copolymers with a poly(N-isopropyl acrylamide) (PNIPAm) central block and short cationic polymeric ionic liquid (PIL) endblocks were synthesized via ATRP. The chemically different blocks interact with each other and thus the presence and length of the PIL blocks affected the aggregation behavior of the thermoresponsive polymers at temperatures below and above the cloud point.The PIL-PNIPAm...
The time-temperature superposition property of an amorphous polymer acrylate network is characterized at infinitesimal strain by standard dynamic mechanical analysis tests. Comparison of the shift factors determined in uniaxial tension and in torsion shows that both tests provide equivalent time-temperature superposition properties. More interestingly, finite strain uniaxial tension tests run until...
The microscopic mechanism of high-density polyethylene under uniaxial drawing is investigated using in situ Raman spectroscopy. From the peak shifts of the symmetric and anti-symmetric C–C stretching modes, it is found that the load sharing on the polymer chain in the yielding region is anisotropic with stretching along the chain and compression perpendicular to the chain. The orientation functions...
A new and non-invasive technique based on confocal laser scanning microscopy (CLSM) that allows the visualization of penetrant diffusion in-situ has been developed and was applied to quantify local solute dynamics in polymeric films. The effectiveness of the proposed technique was demonstrated using a model penetrant, rhodamine-6G (Rh-6G), and a system of polyvinyl alcohol (PVA) films with different...
Templates are used extensively for materials synthesis applications. A material, the morphology of which can be controlled by utilizing different material deposition methods, is formed within the template followed by its removal. In this work an in situ, one-step synthesis protocol is employed to produce polystyrene and polymethacrylate microtubes within small-diameter fused silica templates. The...
We report the synthesis and photovoltaic properties of a donor–acceptor polymer, poly(naphthobisthiadiazole-triphenylamine) [poly(NTD-TPA)], which consists of TPA as a donor unit and NTD as a stronger acceptor than benzothiadiazole. This polymer had an absorption edge at wavelengths up to 610 nm. The optimized bulk-heterojunction (BHJ) organic photovoltaic (OPV) cell using poly(NTD-TPA) and [6,6]-phenyl...
Polyethylene (PE) is available in various grades ranging from high-density to very-low density (co-)polymers. The morphology of PE strongly influences its properties and is extensively studied, including the content of phases. Most studies are usually concerned only with the crystallinity and non-critically adopt the classical three-component model of PE, which considers a crystalline (rigid) and...
Here, we described a simple approach for the development of advanced composites based on Nylon 12 by selectively modified multiwalled carbon nanotubes (MWCNTs). Prior mixing, MWCNTs were modified by a new combination of plasma treatment i.e. oxygen + nitrogen (PL-MWCNTs) in order to improve its dispersion in the nylon matrix and enhance the interfacial adhesion by increasing the compatibility. With...
Multiple Particle Tracking (MPT) microrheology in combination with bulk mechanical rheometry has been used to characterize the structural and viscoelastic microheterogeneity of commercial acrylic thickeners Carbopol EDT2050, Viscalex HV30, and Sterocoll D in aqueous solutions at technically relevant polymer concentrations. According to bulk rheology Carbopol solutions exhibit a much higher elasticity...
In this paper, we presented the fabrication of human hair derived keratin/poly(vinyl alcohol) composite nanofibers exhibiting high optical transmittance by using simple and versatile electrospinnig technique. Keratin was extracted from human hair by sulphitolysis process and glyoxal solution was used as crosslinking agent in the system. More interestingly, the high optical transmittance (∼88% at a...
Thermal and volumetric properties of mixed epoxy networks were characterized with molecular dynamics simulation. Atomistically detailed models of epoxy networks of diglycidyl ether of bisphenol (DGEBA) cured with stoichiometric binary mixtures of a flexible cross-linker poly(oxypropylene) diamine (POP) and a stiff cross-linker 4,4′-methylenebis(cyclohexylamine) (MCA), having molecular weights of 1987...
The ballistic performance was examined for a series of broad glass transition temperature epoxy formulations consisting of a di-epoxy monomer crosslinked with bi-modal mixtures of both a rigid, low molecular weight diamine and a flexible, high molecular weight diamine. Interestingly, the resins did not macro-phase separate during cure, but exhibited structural and dynamic heterogeneity on a length...
PMMA gels synthesized by RAFT polymerization and corresponding gels made by free radical polymerization (FRP) were characterized macroscopically by determining the shear moduli and the swelling ratios, and microscopically by dynamic light scattering (DLS) with particular emphasis on inhomogeneity. The gels were prepared in the solvent γ-butyrolactone at concentrations ranging from 13 to 20 wt% (15–22...
Electrospinning is a relatively simple method of producing nanofibres. Currently there is no method to predict the characteristics of electrospun fibres produced from a wide range of polymer/solvent combinations and concentrations without first measuring a number of solution properties. This paper shows how artificial neural networks can be trained to make electrospinning predictions using only commonly...
We describe a novel thermo-responsive fiber mat showing controlled release of liquids upon heating. The fiber mat was composed of electrospun thermoplastic polyurethane (TPU) nanofibers, with liquid-filled inter-fiber spaces (pores). On heating above 60 °C, nanofibers underwent substantial contraction. This solid deformation was attributed to the heat-induced relaxation of a non-equilibrium stretched...
In the present study, to enhance the tensile and fracture toughnesses of epoxy/clay composites without compromising the strength, a modifying copolymer in-situ synthesized for clay modification during epoxy curing was incorporated to form an interpenetrating network (IPN) structure within epoxy network, leading to a double IPN structure. The IPN structure formed between the clay and the modifying...
A series of cross-linkable membrane materials based on the 6FDA-DAM:DABA (3:2) polyimide with enhanced transport plasticization resistance were synthesized to separate CO 2 from CH 4 . Glycidol was used as a cross-linking agent to modify 6FDA-DAM:DABA (3:2) efficiently and form a transesterification reaction-based cross-linking. The conversion was calculated by solution 1 H...
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