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Ring-opening polymerization of a cyclic dithiocarbonate initiated by arylmethyl triflates, derived from benzyl bromide and bis-, tris-, and tetrakis(bromomethyl)benzenes. Synthesis of star-shaped polymers with cores, transferred from initiators and fluorescent dyes (naphthalene, anthracene, perylene) embedded polymers.
Three types of aromatic polyketones bearing tetrakis(nonafluorobutyl)-pterphenylene units were successfully synthesized via nucleophilic aromatic substitution polymerization. In particular, high-molecular-weight polymers were obtained in DMAc. These polymers have water and oil repellency, good thermal stability, and excellent solubility in typical organic solvents such as MEK, THF, CHCl3, and DMAc.
Copolymers of [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETAC) and acrylamide (AAm) (AETAC-co-AAm) are polyelectrolytes used as flocculants in wastewater purification. Diffusion-ordered dimensional NMR spectroscopy (DOSY) experiments for AETAC-co-AAm samples with Mw ranging from 1.9 to 3.9 million and a polyacrylamide sample with Mw of 1.3 million were carried out in pure D2O and in D2O containing 0.1 or 1 M NaCl using an inverse-geometry diffusion-probe system. Projections of the DOSY contour plots onto the diffusion coefficient (D) dimension gave distributions of D for the AETAC and AAm units in the samples. The D values at the maximum point of the distribution (Dp) agreed fairly well with those determined by dynamic light scattering.
β-cyclodextrin was immobilized on polypropylene nonwoven fabrics in a simple and mild condition. The prepared composite fabrics showed sustained drug release over 12 h.
We studied the effects of polymer encapsulation of 290-nm-sized Al2O3(Al)-coated titanium dioxide (Al-TiO2) particles on the reflectance and hiding power of an inkjet image printed on a polyethylene terephthalate film. Two different polymer shells with 20–30-nm thickness of a poly(methyl methacrylate) (PMMA) shell and a multilayered shell of PMMA and poly(styrene) (PSt) (PMMA/PSt) were prepared using seeded semicontinuous emulsion polymerizations. The brightness (L*) value of the prints from the PMMA- and PMMA/PSt-encapsulated Al-TiO2 inks increased compared to bare Al-TiO2.
Submicron-sized SiO2/Al2O3(Si/Al)-coated titanium dioxide (Si/Al-TiO2) particles were encapsulated through the emulsion copolymerization of methacrylates using a thermoresponsive polymerizable nonionic surfactant, NE-10. An optimized water-dispersion method was developed to disperse Si/Al-TiO2 dried powders using an ultrasonic homogenizer, a paint shaker, and a pot mill rotator in the presence of partially neutralized poly(isobutylene-alt-maleic acid). The encapsulation efficiency (Fen) was affected by the monomer and initiator types, NE-10, and sodium dodecyl sulfonate concentrations. Fen > 90% was achieved by a two-step semibatch emulsion copolymerization under optimized conditions.
A PS/silica hybrid nanomatrix was formed by graft copolymerization of first styrene and then VTES onto NR particles in the latex stage. This hybrid nanomatrix structure was composed of nanosilica with a size of less than 100 nm and PS, which resulted in outstanding mechanical and viscoelastic properties. The superior properties of the hybrid nanomatrix were due to the synergetic effect of PS and nanosilica. The morphology and mechanical properties of the hybrid nanomatrix were maintained after acetone extraction, whereas they were distorted and reduced, respectively, after annealing
