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Two kinds of fluorinated co-oligomeric nanoparticles, RF-(IEM)x-(Ad-HAc)y-RF and RF-(AMPS)x-(Ad-HAc)y-RF, enabled a selective morphological control, which is divided into inclusion type and adsorption type, respectively, for the encapsulation of magnetic nanoparticles into each fluorinated particle core. More interestingly, RF-(AMPS)x-(Ad-HAc)y-RF co-oligomeric nanoparticles can decrease the LCST effectively in organic media such as t-butyl alcohol through the encapsulation of magnetic nanoparticles into these particle cores.
We report the direct synthesis of new functional novolacs having allyl ether in the side chain by the addition-condensation of allyl phenyl ether (1). In polymerization of 1 with formaldehyde using hydrated sulfuric acid as a catalyst, Claisen condensation did not occur with the polymerization; therefore, pure allylated novolac (4) without a phenol moiety was obtained. The obtained polymer (4) can be applicable for a latent curing system.
Phosphorus-containing fire retardants and inert polymers inhibit the hydrolysis of polycarbonate (PC), resulting in an increased reaction time. However, even in the presence of these materials, high yields of bisphenol-A and other phenols can be obtained from waste PC dependent on temperature. At 500 °C, polystyrene is also pyrolyzed.
Porous rods of poly(tetrafluoroethylene) (PTFE) were fabricated by molding PTFE powder and fumaric acid (FA) at room temperature, and sintering at 400 °C. The microstructures of the molding mixtures were observed with a scanning electron microscope (SEM). High-resolution images of SEM revealed that the fibrous structure heated at 310 °C is composed of small particles of PTFE connected with fibrils, and these particles were sintered into grains after heating at 400 °C. Pore size could be controlled by changing the volume fraction of FA.
Optically pure and helical poly(quinoxaline-2,3-diyl)s prepared by asymmetric living polymerization of 1,2-diisocyano-3,6-dimethyl-4,5-di(propoxymethyl)ben zene with an optically pure organopalladium initiator were found to take highly ordered and stable monolayer formation at the air/water interface, providing well-defined multilayer structures with 1.5 nm monolayer thickness.
Birefringence and tensile stress of vulcanized natural rubber samples were measured simultaneously. The effect of finite chain extensibility could be clearly detected. The increase in birefringence was related to the degree of orientation of amorphous chains to be incorporated into crystals. The normalized stress decreased in a manner that is almost independent of network-chain density. These experimental results could be successfully explained by assuming a certain fraction of network chains that behave in a manner similar to that of a fluid.
Poly(butylene succinate) (PBS) copolymers including 1 mol% of amino acid were produced at high molecular weights and good break strain. Preparation of PBS copolymer including L-aspartic acid (3) was found to be quite different compared with the preparation of the copolymer produced using other amino acids. The reaction time was found to decrease in proportion to the amount of 3. A similar effect due to the inclusion of 3 was observed in other PBS copolymers.
The amorphous phase and crystalline morphology of the poly(vinyl methyl ether) (PVME)/poly(1,6-hexamethylene adipate) (PHA) blend were compared with those of the classical PVME/poly(ɛ-caprolactone) (PCL) system, isomeric to the former. Both blend systems’ amorphous phases are similarly miscible with χ12=−0.2. In contrast, the crystalline phases of these two blends differ significantly. When crystallized at high Tc (46 °C or above), the PVME/PCL (20/80) blend assumes fluffy feather-like dendrites (Graph-a), which are dramatically different from straight-stalk dendrites in the PVME/PHA (20/80) blend (Graph-b).
The mean square end-to-end distance 〈R2〉 is dependent on the polymer-surface interaction ɛ. It reaches minimum near critical adsorption point (CAP) ɛc≈−0.29. The result provides an alternate method to determine ɛc.
Polymer reactions of poly(p-phenylene–ethynylene) based on addition reaction of decaborane to the carbon–carbon triple bond were successfully carried out. The platform polymer was synthesized through Sonogashira–Hagihara coupling polymerization. The effective introduction of boron cluster was supported by 1H and 11B NMR spectroscopies. UV-vis absorption and photoluminescence studies illustrate the shortening of an effective p-conjugation length caused by the introduction of carborane clusters. Furthermore, the introduction of the boron cluster by the polymer reaction efficiently enhanced the heat resistance of poly(p-phenylene–ethynylene).
Poly(ethylene glycol) with a molecular weight of 400 (PEG400) as an environmentally benign and highly viscous polymeric solvent was found to effectively accelerate the free radical polymerization of methyl methacrylate and to afford a high-molecular-weight polymer. The polymerization rate and the polymer molecular weight increase linearly with the square root of the viscosity η of the polymerization media. The kinetic study has shown that the highly viscous PEG400 solvent largely suppresses diffusion-controlled bimolecular termination.
The network aggregates of poly(2,5-benzimidazole) nanofibers were prepared by the polymerization of phenyl 3,4-diaminobenzoate at 350 °C in a mixture of dibenzyltoluene isomers. The average diameter of the fibers was ∼60 nm. These fibers were formed by the crystallization of oligoimidazoles and the subsequent polymerization in them.
The second and third virial coefficients (A2 and A3, respectively) for benzyl-end polystyrene in toluene at 15 °C are determined by light scattering. The figure shows that A2 data for benzyl-end (unfilled circles) and butyl-end (filled circles, literature data) polystyrenes can be fitted by the theoretical curves (solid and dashed curves) when the chain-end effect is incorporated into the theory without that effect (dotted curve).
The weak gel was prepared by polycondensation of polyacrylamide and resol. The reaction mechanism was clarified by molecular simulation and experiment characterization. The reaction thermodynamics was analyzed to judge the reaction possibility by DMol3. Reaction dynamics were applied to determine the predominant reaction by transition state research, and the results of X-ray photoelectron spectrum confirmed the simulation results.
A polysilsesquioxane having a bis(2–methoxyethyl)amide group and 15-crown-5-ether ring (MCPSQ) was newly prepared. In the behaviors of hydrophobic aggregation in the aqueous solution containing the chloride of alkali metals, the highest LCST was observed in the solution containing sodium ion as expected from the ring size of the crown ether. By the addition of sodium 4-phenylazobenzoate, the photochemical isomerization affected the aggregation behavior of MCPSQ.
Novel anionic polymerizable surfactants were prepared by reacting maleic anhydride with different benzyl alcohols. These surfmers were evaluated in the emulsion polymerization of styrene in the presence of potassium persulfate as the initiator. Special attention was focused on the effect of the concentration of surfmers on the polymerization kinetic and the final particle size through polymerization conversion particle size and size distribution determination.
Largely improved strength and abrasion resistance for styrene–butadiene rubber (SBR)/silica composites are demonstrated when sorbic acid (SA) is incorporated in the compounds. The abrupt changes in performance are attributed to the strong interactions between silica and SA and the largely improved dispersion of silica, which are realized by SA-intermediated linkages through grafting copolymerization and hydrogen-bonding mechanisms.
The surface-initiated graft polymerization of covalently bound polymer brushes attached to an sp3 random carbon network backbone structure is demonstrated. Poly(ethyl acrylate) (PEA), poly(4-fluorostyrene) (PFS) and poly(acrylonitrile) (PAN) brushes were grafted from the network backbone polymer poly(hydridocarbyne), 1, illustrating the breadth of reactivity of the network backbone. The grafted polymer brushes significantly change the solubility and surface characteristics of the poly(hydridocarbyne) sp3 random carbon network backbone.
