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Living poly(n-hexyl isocyanate) (PHIC) was deactivated with methacryloyl chloride to produce methacryl-terminated poly(n-hexyl isocyanate) (PHIC-MA) rodlike macromonomers. Radical copolymerization of methyl methacrylate (MMA) with PHIC-MA was performed using 2,2'-azobis(isobutyronitrile) as an initiator in benzene at 60 o C to prepare poly(methyl methacrylate)-graft-poly(n-hexyl isocyanate)...
A novel series of photocurable biodegradable polyesters (CAC/PCL) were synthesized by a high-temperature solution polycondensation of poly(ε-caprolactone) (PCL) diols varying molecular weight (M W ; 1250, 2000, 3000) and a diacyl chloride of 4,4'-(adipoyldioxy)dicinnamic acid (CAC) as a chain extender derived from adipic acid and 4-hydroxycinnamic acid. The resulting polyesters were photocured...
The melt polycondensation reaction of trans-4-hydroxy-N-benzyloxycarbonyl-l-proline (N-CBz-Hpr) and functional cyclic esters containing protected functional groups (carboxyl, and amino) at a wide range of molar fractions in the feed produced new degradable poly(N-CBz-Hpr-co-functional-ε-CL)s with stannous 2-ethylhexanoate (Sn(Oct) 2 ) as a catalyst. The optimal reaction conditions for the...
The partitioning of a single polymer chain into a slit in a good solvent with different surface interactions is examined through Monte Carlo simulations from subcritical regime to adsorptive regime. The chain conformation in the subcritical regime is not perturbed by the surface interactions significantly. In the adsorptive regime, the conformation of the chain is strongly perturbed by the surface...
Polyacetylene (PA), poly(cis- and trans-1,4-butadiene)s (cis- and trans-PBs), and poly(p-phenylene vinylene) (PPV) were ablated by synchrotron radiation (SR), aiming to deposit thin, uniform films of each on a substrate. When PA was irradiated by SR, gaseous phenyl compounds were produced, and a thin amorphous film was deposited on the substrate, exhibiting no characteristics of PA. In the cases of...
Swelling and mechanical properties were investigated for superporous hydrogels (SPHs) of poly(acrylamide-co-acrylic acid)/polyethylenimine (P(AM-co-AA)/PEI) interpenetrating polymer networks (IPNs). Gelation kinetics of SPHs changed significantly according to the acidic condition of reactant. The compressive strength of neutralized SPHs decreased monotonically with AA concentration, while the maximum...
Porous crosslinked poly(vinyl alcohol) resin beads have been prepared by a two-step pathway involving a pre-crosslinking reaction followed by a reverse suspension crosslinking reaction with epichlorohydrin as crosslinker. The reaction conditions have been optimized for the two steps in order to obtain resins with various pores sizes. The crosslinking density of these resins was calculated from their...
Sequential networks made of hydroxypropylcellulose (HPC) and poly(N-isopropylacrylamide) (PNIPA) were synthesized by adsorption of a solution of NIPA monomer into a dried porous HPC network. NIPA polymerization inside the network allows us to obtain IPN which show, as the neat components, thermosensitive volumetric behavior. The volumetric transition temperatures range between those of HPC and PNIPA...
The microhardness behaviour of binary blends comprising a styrene/butadiene star block copolymer and polystyrene homopolymer (hPS) over a wide composition range is investigated. In particular, the interrelation between the morphology, tensile properties (such as yield stress σ Y and the Young's modulus, E) and the microhardness H is explored. As in the case of microphase separated block copolymers...
Nonlinear optical (NLO) poly(adamantyl methacrylate-methylvinylurethane)s were prepared by functionalisation of adamantyl methacrylate vinyl isocyanate precursor polymers. A modified pathway to obtain phenyltetraene-bridged chromophore was worked out. Poled films of the polymers show high and very stable NLO response even at elevated temperatures.
A novel synthetic method of poly(methyl methacrylate) (PMMA)/silica nano-composite with well-segregated PMMA and silica domains was proposed. To obtain the nano-composite, a poly(methyl methacrylate)-block-poly(2-hydroxyethyl methacrylate) (PMMA-block-PHEMA) film with PMMA and PHEMA domains was soaked into a pyridine/m-xylene/perhydropolysilazane (PHPS) mixture and calcinated at 90 o C under...
The ATRP of methyl methacrylate (MMA) with the system of FeCl 2 .4H 2 O, N,N,N',N'',N''-penta(methyl acylate)diethylenetriamine (MA 5 -DETA) and ethyl 2-bromoisobutyrate (EBiB) showed high activity and is not well-controlled. The addition of a certain amount of FeCl 3 .6H 2 O as the additive into the above system results in the decrease of the polymerization...
Novel polymeric photoinitator (PTX) was synthesized by introducing thioxanthone (TX) moieties to polymeric amine side-chain. Compared with low-mulecular weight model compound, PTX has similar UV-vis absorption and weaker fluorescence emission, and some radicals are trapped in the macromolecular coil cage. The kinetics for polymerization of trimethylolpropane triacrylate using PTX as photoinitiator...
Nanofibrous mats were prepared by electrospinning of poly(trimethylene terephthalate) (PTT) with diameter ranging from 200 to 600 nm. Morphology of electrospun nanofiber obtained by changing processing parameters such as solution concentration and their deposition time, was investigated with scanning electron microscope (SEM). Especially, periodic feature of surface roughness, such as diamond-shaped...
Dielectric spectroscopy in the frequency range from 10 -2 to 10 6 Hz and in the temperature range from 190 to 440 K is employed to study the effect of azobenzene concentration on the dielectric relaxation processes of an amorphous comb-like copolymethacrylate. Four concentrations (x=29, 45.5, 54, and 74.5mol%) of photochromic group 4-amino-azobenzene were investigated, where as...
Some structural details and the viscoelastic and mechanical response of blends of a vinyl alcohol-ethylene (VAE), and a metallocenic ethylene-1-octene copolymer (CEO), have been analyzed. Both copolymers exhibit crystalline lattices whose diffraction peaks and long spacings appear at very similar spacing intervals. More information about the crystalline region is obtained from differential scanning...
The fatigue behaviour of poly(aliphatic/aromatic-ester) (PED) multiblock copolymers has been evaluated using the hysteresis loop method. Stepwise increasing strain test (SIST) was performed at a frequency of 1 Hz. The strain levels were varied with increasing extension steps: 3, 5, 10, 15, 20, 25 and 30% of the initial strain, while minimum stress has been set at a constant value of 0.1 MPa. It has...
Different types of polyethylene blown films (HDPE, LDPE, LLDPE) differ significantly in the ratio between machine and transverse direction tear resistance. In this paper, low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) blown films at different draw-down ratios are studied, and the relation between crystalline structure and anisotropy of...
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