The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The synthesis of amphiphilic diblock copolypeptides consisting of poly(α-l-glutamic acid) (PLGA) and poly(γ-methyl-l-glutamate-ran-γ-stearyl-l-glutamate) with 30mol % of stearyl substituents (PMLGSLG) and their monolayer behavior at the air–water interface have been studied. PLGA-b-PMLGSLG was synthesized via a diblock copolymer precursor consisting of poly(γ-tert-butyl-l-glutamate) (PtBuLG) and PMLGSLG...
Addition of styrene (S)/4-hydroxystyrene (HS) block, blocky gradient, or blocky random copolymer to 80/20wt% polystyrene (PS)/polycaprolactone (PCL) blends is examined as a compatibilization strategy. Four copolymers are synthesized by controlled radical polymerization, each with an S block and the other block being a HS block or S/HS random or gradient copolymer. Compatibilization depends on copolymer...
An environmentally benign process, which uses supercritical carbon dioxide (sc-CO 2 ) as a processing aid, is developed in this work to help exfoliate and disperse nanoclay into the polymer matrices. The process relies on rapid expansion of the clay followed by direct injection into the extruder where the mixture is dispersed into the polymer melt. Results from the mechanical properties, rheological...
Styrene (S)/4-hydroxystyrene (HS) copolymers are synthesized by hydrolysis of S/4-acetoxystyrene copolymer precursors; two gradient copolymer precursors are made by semi-batch, nitroxide-mediated controlled radical polymerization, and a random copolymer precursor is prepared by conventional free radical polymerization. Conventional heat curves from differential scanning calorimetry indicate two glass...
Styrene/4-hydroxystyrene block and gradient copolymers containing the organic dye Disperse Red 1 (S/HSDR) were synthesized using nitroxide-mediated controlled radical polymerization, and a random copolymer was made using conventional free radical polymerization. The three types of S/HSDR copolymer, with similar molecular weight and composition but different S/HSDR sequence distributions along each...
Styrene/4-methylstyrene (S/MS) random and gradient copolymers were synthesized by nitroxide-mediated controlled radical polymerization (NM-CRP) and compared to random copolymers made by conventional free radical polymerization (ConvFRP). The gradient copolymers have molecular weight (MW) values approaching 85,000 g/mol, making these some of the higher MW gradient copolymers reported to date. Due to...
The initiation efficiency of acylphosphine-oxides has been evaluated in different types of UV-curable resins. Real-time infrared spectroscopy was used to monitor in situ the polymerization process in thin coatings exposed to UV-radiation. When compared to typical radical photoinitiators, acylphosphine oxides proved to be the most efficient ones with respect to both the polymerization rate and the...
Interpenetrating polymer networks (IPNs) have been synthetized by light-induced cross-linking polymerization of a mixture of acrylate and epoxide monomers. The consumption of each monomer upon UV-irradiation in the presence of radical and cationic-type photoinitiators was monitored in situ by real-time infrared spectroscopy. The acrylate monomer was shown to polymerize faster and more extensively...
A thermoplastic elastomer, polystyrene-block-polybutadiene-block-polystyrene (SBS) with a high vinyl content (59%), was crosslinked within a fraction of a second by UV-irradiation in the presence of a trifunctional thiol and an acylphosphine oxide photoinitiator. The curing process was followed by IR spectroscopy, insolubilization and hardness measurements. Both the thiol and the photoinitiator concentrations...
Permeation fluxes of water and acetic acid from water-acetic acid mixtures were independently monitored as a function of time in differential permeation with dual detection. Two successive permeation waves were detected for water permeation and only one for acetic acid permeation in the transient regime. The onset of the second permeation wave for water coincides with that of acetic acid permeate...
The temperature of crystallization and of melting of water in poly(vinyl alcohol) (PVA) membranes with various degrees of acetylation have been measured at different cooling and heating rates, and compared to the glass transition temperature (T g ) of the swollen materials. Above a certain critical concentration of water, c * , when water begins to crystallize upon cooling, the T...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.