- Thermal degradation kinetics of semi-interpenetrating polymer network based on polyurethane and siloxane
-
A series of semi-interpenetrating polymer networks based on linear polyurethane and 1,3-bis(glycidyloxypropyl)-1,1,3,3-tetramethyldisiloxane, which was cross-linked with diethylenetriamine, were obtained. The samples have been submitted to thermal stability investigations at non-isothermal conditions in nitrogen. The kinetic parameters of the degradation process were determined both by isoconversional methods of Friedman and Ozawa-Flynn-Wall as well as by model fitting multivariate non-linear regression method. It was observed that the thermal stability of the semi-interpenetrating polymer networks depends on siloxane content. The best fit of the f(α) function with the experimental data was found for three-step degradation mechanism. Successive stages of thermal decomposition occurred by diffusion, phase-boundary and autocatalysis models, respectively.
- Byczyński, ?ukasz,Dutkiewicz, Micha?,Maciejewski, Hieronim
-
-
Read Online
- (Aminophenyl)porphyrins as precursors for the synthesis of porphyrin-modified siloxanes
-
The present research reports the efficient synthesis of mono- and di-(aminophenyl)porphyrins and their metalation with Zn(II) using microwave irradiation. The subsequent reaction of amino-functionalized porphyrins with siloxane moieties bearing epoxy or carboxyl functional groups provided four new porphyrin-modified siloxanes. The structure of the resulting derivatives was established by 1H-NMR and MALDI-TOF-MS. The optical properties of the porphyrin chromophores were preserved, as proven by comparing the absorption and emission spectra of the initial porphyrins to those of the porphyrin-modified siloxanes.
- Almeida, José,Fortunǎ, Maria E.,Pricop, Lucia,Lobiuc, Andrei,Leite, Andreia,Silva, André M.N.,Monteiro, Rodrigo P.,Rangel, Maria,Harabagiu, Valeria,Silva, Ana M.G.
-
p. 1001 - 1012
(2019/05/22)
-
- Hydrosilylation of Allyl Ethers in the Presence of Supported Sulfur-Containing Platinum(II) Complexes
-
Hydrosilylation of allyl ethyl, allyl butyl, allyl glycidyl, allyl benzyl, and allyl phenyl ethers by 1,1,3,3-tetramethyldisiloxane in the presence of supported sulfur-containing platinum(II) complexes with the general formula [{SiO2}O2S/
- de Vekki,Il’ina,Skvortsov
-
-
- Spectral study of interaction between allyl ethers and hydrosiloxanes
-
Interaction of allyl ethers with hydrosiloxanes in the presence of metal complexes has been investigated by spectral methods (1H NMR, IR, and GC-MS) as well as by gas-liquid chromatography. It has been shown that the anti-Markovnikov addition p
- Il'Ina,De Vekki,Skvortsov
-
-
- FILM FORMING PERSONAL CARE COMPOSITIONS AND METHODS
-
Compositions, kits and methods of preparing a biocompatible film for cosmetic or medical uses are disclosed. The compositions or kits contain polyvinyl acetal (PVA), siloxane and a solvent. The siloxane can have a hydrophilic group. Once the solvent content is reduced, for instance, by evaporation, the mixture of PVA and siloxane is solidified, forming a film. The compositions and kits, optionally, further include one or more of an antimicrobial agent, a pigment, an anti-inflammatory agent, an anesthetic agent or a hemostatic agent. Such a film can be used, for example, in the form of an antimicrobial sealant, a liquid bandage, body paints, scar camouflage, water-proof sun block, makeup sealer, or antimicrobial wipe or spray.
- -
-
-