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We report the application of reversible addition-fragmentation chain transfer (RAFT) polymerization using poly(dimethylsiloxane) (PDMS) chain transfer agents toward the synthesis of a variety of diblock copolymers containing tert-butyldimethylsilyl methacrylic (MASi) monomer units. The methodology relies on the synthesis of PDMS monofunctional chain transfer agents easily available in one synthetic...
Co-crystallizing a monomer capable of forming a three-dimensional covalent organic framework (3D COF) with a truncated analog represents a robust strategy to functionalize the pores of these crystalline polymer networks. Here we elaborate this approach by demonstrating that monofunctional arylboronic acids serve as effective truncation/functionalization agents for COF-102, a boroxine-linked 3D network...
Poly(3-hexyl thiophene) (P3HT) is widely studied as a model material in many electrical and photovoltaic applications, and has become the benchmark polymer when studying the physics of these devices. Despite its extensive use, its precise crystalline structure and thermodynamic characteristics, such as its enthalpy of melting of an ideal crystal, crystalline density, and amorphous density, are not...
Porous copolymers of styrene and divinylbenzene (DVB) were prepared by emulsion templating using high internal phase emulsions (HIPEs) as precursors for monoliths. The ratio of monomers was varied in order to obtain samples with different degrees of crosslinking and different amounts of unreacted vinyl groups originating from DVB. PolyHIPE monoliths were subjected to reswelling and treatment with...
Porous Polymer Networks (PPNs) are an emerging category of advanced porous materials that are of interest for carbon dioxide capture due to their great stabilities and convenient functionalization processes. In this work, an intrinsically-functionalized porous network, PPN-101, was prepared from commercially accessible materials via an easy two-step synthesis. It has a BET surface area of 1095 m2/g...
Local dynamics of polyacetylenes having polymethylated indan/tetrahydronaphthalene moieties have been studied using quasielastic neutron scattering, and the results obtained have been discussed together with former results with various poly(diphenylacetylene) derivatives. Clear quasielastic scattering was observed for the present polymers although they were in the glassy state, and the observed dynamic...
Polystyrene nanoparticles, cross-linked with divinylbenzene (PS-(DVB)x) and having radii, Rp ≤ 10 nm, have been synthesized using batch and semi-batch radical microemulsion polymerizations. The nanoparticles were characterized thoroughly using 1H NMR, size exclusion chromatography, differential scanning calorimetry, and various small-angle scattering techniques (light, X-rays, and neutrons). Control...
The surface and mechanical properties of hybrid films of waterborne polyurethane (WPU) and fluorinated polymethacrylate (FPMA), and high-hydrophobic silica (SiO2) contained hybrid films of FPMA/WPU were investigated. X-ray photoelectron spectroscopy confirmed that the surfaces of hybrid films exhibited notable fluorine enrichment. Scanning electron microscopy observation demonstrated that micro-scale...
Time evolution of 3-D structure of GO hydrogels was explored by rheological measurements. We showed that the GO hydrogels were thickened drastically by oscillatory shear flow if and only if both the angular frequencies and shear strain are small. We also showed that the plateau modulus (GN′) of GO hydrogels is rheological premonitory of ultra-light aerogels. The ultra-light aerogel fabricated in this...
We report thermal conductivity (κ) of low-density, high-density and ultra-high density polyethylene (PE) with different crystallinity and microstructures. PE was crystallized under high-pressure and high-temperature conditions which produce extended chain crystals. By applying a two-phase model, we estimate κ of 100% crystallized PE as a function of pressure and temperature. The increased crystallinity...
The influence of polyesters end-groups on cyclic oligoester formation is investigated using a series of hydroxy-, carboxy- and methylester-terminated aliphatic polyesters, in the presence of various ester interchange catalysts. The presence of hydroxy end-groups is the preponderant factor on cyclodepolymerization kinetics. This indicates that the main reaction is the intramolecular hydroxy–ester interchange...
A series of optically inactive aryl isocyanide derivatives were polymerized with an achiral nickel catalyst (Ni(II)Cl2) in a cholesteric liquid crystal (CLC) medium. The polymers synthesized from ortho-substituted phenyl isocyanide monomers in CLC phase show optical activity even though they have no chiral carbons. The Cotton effects of these polymers suggest that main chains of the polymers formed...
A novel poly(arylene ether sulfone) (PAES) block copolymer was prepared from previously synthesized fluoride terminated oligomer (A16) and hydroxyl terminated oligomer (B12) by aromatic nucleophilic substitution polycondensation reaction. PAES was subsequently sulfonated under controlled conditions to yield a copolymer (S-PAES) with sulfonic acid groups selectively in the B12 segments and without...
In this study, we report layer thickness effect on the electrical insulation property of polysulfone (PSF)/poly(vinylidene fluoride) (PVDF) multilayer films having a fixed composition of PSF/PVDF = 30/70 (vol./vol.). Breakdown strength, dielectric lifetime, and electrical conductivity were studied for 32- and 256-layer films having various total film thicknesses. Among these films, those having thinner...
A series of P(MMA-co-GMA)-b-PMAPOSS block copolymers (BCPs) were synthesized by ATRP. The BCPs contain POSS (polyhedral oligomeric silsesquioxane) as a pendant unit on a particular polymer block chain. In selective solvents, the BCPs self-assemble to form ordered micellar-like structures. Spherical, cylindrical or vesicle-like morphologies were produced by tuning the BCP and mixed solvent compositions...
Cell patches are widely used for healing injuries on the surfaces or interfaces of tissues such as those of epidermis and myocardium. Here we report a novel type of porous scaffolds made of poly(d,l-lactic-co-glycolic acid) for fabricating cell patches. The scaffolds have a single layer of spherical pores arranged in a unique hexagonal pattern and are therefore referred to as “scaffolds with a hexagonal...
Isotactic poly(1-butene) (i-PBu) is a polyolefin of industrial relevance which exhibits an interesting polymorphism. Upon cooling from the relaxed melt at atmospheric pressure, a tetragonal phase (Form II) develops. However, being metastable, this structure slowly evolves upon aging in the stable trigonal modification (Form I). Another trigonal modification, denoted Form I′, can also crystallize directly...
The greatest challenge in developing polymer/graphene nanocomposites is to prevent graphene layers stacking; in this respect, we found effective solution-mixing polymers with cost-effective graphene of hydrophobic surface. Since graphene oxide is hydrophilic and in need of reduction, highly conducing graphene platelets (GnPs) of ∼3 nm in thickness were selected to solution-mix with a commonly used...
This study aims to investigate interconnectivity and permeability of scCO2-foamed scaffolds and the influence of structural scaffold properties on cell distribution. Supercritical fluid technology was utilized to fabricated scaffolds from 37 kDa, 53 kDa and 109 kDa PLGA (85:15). Pore size, pore size distribution and porosity were quantified by MicroCT, and window sizes were measured using SEM. A novel...
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