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The microstructures of fluorinated polyurethanes (FPUs) possess separated soft and hard phases related to their unique mechanical and physiochemical properties. We studied the microstructures of FPUs and H-bond interactions focusing on the influences of fluorine (F) content on the separation between the soft and hard phases by combining experimental and computational approaches. FPUs featuring F in...
Poly(glycidyl methacrylate) polymer brushes were grafted onto TiO 2 nanoparticle surfaces via a combination of phosphate ligand engineering and Cu-catalyzed alkyne-azide “click” reaction. The grafted TiO 2 nanoparticles are compatible with a commercial epoxy resin enabling the preparation of thick (1 mm) transparent high-refractive index TiO 2 /epoxy nanocomposites. In order...
A predictive multiscale computational framework has been proposed to study the viscoelastic properties of polymeric materials. Using the Inverse Boltzmann Method, both the static structures and dynamic behavior of all-atomistic models of polymers can be reproduced by a simple coarse-grained model, which bridges the scale from nano to meso. On this coarse-grained level, the entangled network of polymer...
In this paper, the polymer chain packing and primitive path (PP) network of uncrosslinked and crosslinked cis-polyisoprene (PI) polymer are analyzed upon employing coarse-grained molecular dynamics simulation. The crosslinking effect is found to enhance intra-chain packing of PI polymers, while weakening their inter-chain packing. Surprisingly, these effects cancel each other in the global packing...
The reinforcement mechanism of nano inclusions on the mechanical properties of nanocomposites is still a controversial issue. In this work, the polyethylene (PE) polymer nanocomposites were simulated by infusing different kinds of nano inclusions (bucky-ball, graphene, single-walled-carbon-nanotube (SWNT), X-shaped SWNT junction and Y-shaped SWNT junction) into PE matrices. The effects of these nano...
Novel core-sheath nanofibers, composed of polyacrylonitrile (PAN) core and polypyrrole (PPy) sheath with clear boundary between them, were fabricated by electrospinning PAN/FeCl 3 ·6H 2 O bicomponent nanofibers and the subsequent surface-initiated polymerization in a pyrrole-containing solution. By adjusting the concentration of FeCl 3 ·6H 2 O, the surface morphology...
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)...
Well-defined dually responsive block-brush copolymer of poly(ethylene glycol)-b-[poly(N-isopropylacrylamide)-g-poly(N,N-dimethylamino-ethylmethacrylate)], [PEG-b-P(NIPAM-g-PDMAEMA)] was successfully prepared by the combination of atom transfer radical polymerization (ATRP) and click chemistry based on azide-capped PDMAEMA and alkyne-pending PEG-b-PNIPAM copolymer. Azide-capped PDMAEMA was synthesized...
A silicate-selective polymer-supported reagent has been developed that utilizes the reactivity of silicate to generate polyanionic Keggin structures. Heptamolybdate and heptatungstate anions are immobilized onto trimethylammonium ligands bound to microporous poly(vinylbenzyl chloride) beads. The heptamolybdate complexes >90% of the silicate from a 20ppm solution at pH 7; the heptatungstate has...
The morphology of two polypropylene/poly(ethylene-co-propylene) (PP/EPR) in-reactor alloys prepared by multi-stage sequential polymerization (MSSP) and two-stage polymerization (TSP) processes, respectively, was investigated. It is observed that the alloy prepared by MSSP (sample 1) exhibits lower phase separation temperature than the alloy prepared by TSP (sample 2), probably due to the higher content...
Free-radical melt grafting of the multi-monomer system of maleic anhydride (MAH)/styrene (St) onto polypropylene (PP) was studied using a single-screw extruder. The effects of St and initiator concentrations on the grafting reaction were investigated. It was shown that the addition of St to the melt-grafting system as a comonomer could significantly enhance MAH graft degree onto PP. The maximum MAH...
The influence of interfacial adhesion on the impact toughness of poly(vinyl chloride) (PVC)–nitrile rubber (NBR) blends with the morphology of well-dispersed rubber particles has been investigated. The blend containing NBR 18 (NBR with 18wt% acrylonitrile (AN)) has medium interfacial adhesion strength, and exhibits a brittle–ductile transition at a critical matrix ligament thickness Tc=0.059μm while...
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