Two highly sulfonated micro/mesoporous polymers, P(1,3‐DEB)‐SO3H and P(1,4‐DEB)‐SO3H, with permanent porosity, the specific surface area about 550 m2 ⋅ g−1 and the content of SO3H groups of 2.7 mmol ⋅ g−1 were prepared as new acid Porous Polymer Catalysts, PPCs. The PPCs were achieved by easy sulfonation of parent hyper‐cross‐linked micro/mesoporous polyacetylene‐type networks resulting from a chain‐growth homopolymerization of 1,3‐ and 1,4‐diethynylbenzenes. New PPCs are reported as highly active and reusable heterogeneous catalysts of esterification of fatty acids with methanol and ethanol, Prins cyclization of aldehydes with isoprenol and intramolecular Prins cyclization of citronellal to isopulegol. The catalytic activity of the micro/mesoporous PPCs (TON values up to 522 mol ⋅ mol−1) was higher than that of commercial polymer‐based heterogeneous catalyst Amberlyst 15 possessing gel texture without permanent pores and that of p‐toluenesulfonic acid applied as a homogeneous catalyst.
Kinetic regularities of epoxy resins chemical modification by aliphatic and aromatic dibasic acids have been studied. The commercial dianic resins ED-20 and ED-24 were used as epoxy resins. Oxalic, malonic, succinic, sebacic, maleic, terephthalic and isophthalic acids were used as dibasic carboxylic acids. The effective rate constants and activation energies of the reactions between epoxy resin and acids by different nature have been calculated. The synthesis method for oligomers with epoxy and carboxy groups has been suggested. The structure of synthesized oligomers was confirmed by chemical analyses and IR-spectroscopy.
The mechanism of diepoxide and adipic acid (AA) reaction in the presence of benzyltriethylammonium chloride and 1,4-diazobicyclo[2,2,2] octane has been proposed. The thermal stability of the oligoester obtained via chemical modification of the dioxydiphenylpropane diglycidyl ether with AA and epoxy-oligoesteric mixtures with its participation has been studied. The viscoelastic properties of films based on epoxy-oligoesteric mixtures containing Epidian-5 epoxy resin, TGM-3 oligoesteracrylate, AA modified Epidian-5 and polyethylpolyamine have been determined.
Polymer
brush coatings are effective in preventing blood coagulation
or bacterial attachment, but their chain conformation, while vital
for this effect, was never characterized in high spatial resolution.
Here, we report mid-infrared spectroscopic nanoscopy studies of few-nanometer-thin
poly(ethylene oxide) (PEO) films which reveal marked spectral variations
along the surface at a length scale smaller than 100 nm and originating
only from the physical conformation of the chains. The conformation
and average orientation of the polymer chains in the layer is extracted
from the spectra with the aid of theoretic modeling, confirming the
spontaneous formation of a crystalline phase. This result suggests
spectroscopic nanoscopy as a powerful new tool to characterize polymer
brush coatings.
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