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.
A series of triptycene-based copolyimides with varying backbone rigidity was synthesized and evaluated for chain packing behavior and gas transport properties. These copolymers were composed of a rigid element with the triptycene skeleton directly linked to imide rings and a relatively flexible element containing ether linkage and CF3 substituent groups. The ratio of the two components was systematically...
We realised spring/spacer elements, which are crucial components of capacitive energy harvesters, by syringe printing of polyurethane diacrylate and ethylhexyl acrylate based high (HIPE) and medium (MIPE) internal phase emulsion templates followed by UV polymerisation. The resulting micropatterned poly(merised)H/MIPEs are very flexible and reversibly compressible to a strain of 50% as cyclic compression...
Covalent triazine-based frameworks (CTFs) are a subclass of conjugated microporous polymers (CMPs) that can be used as organic photocatalysts for photocatalytic hydrogen evolution from water. Seven materials with varied spacer units from phenylene to quarterphenylene were synthesized, either by trifluoromethanesulfonic acid (TfOH) catalysis from nitriles or by Suzuki-Miyaura polycondensation. The...
This paper describes the feasibility of achieving melt-processable polyacrylonitrile copolymer precursors for producing high strength carbon fibers. High molecular weight poly(acrylonitrile-ran-methyl acrylate) (PAN-MA) copolymers with high acrylonitrile content were mixed were various binary melting point modifiers with one component being water to produce systems that formed stable melts at temperatures...
Microfibrillated cellulose (MFC) fibers were alkylated by propargyl bromide, allyl bromide and propyl bromide in an aqueous medium without any stirring. The chemical modifications were confirmed by Fourier transform infrared spectroscopy (FTIR), solid-state 13C nuclear magnetic resonance spectroscopy (NMR) and X-ray photoelectron spectrometry (XPS). The alkylated MFC fibers were obtained with degrees...
The deposition of porous polymer membranes was patterned using poly(dimethylsiloxane) (PDMS) masks. The porous polymer was deposited by introducing the monomer and initiator sequentially to allow for the temperature, pressure, and duration of each step to be controlled independently. The porosity and thickness of the membranes was controlled by varying the substrate temperature during monomer deposition...
The present study investigates the thermomechanical behavior of TPU foams. Different densities were tested, including the compact state, which ensures a relevant characterization of the relative effect of the void volume fraction. A series of cyclic uniaxial tensile tests was carried out at different loading rates and different specimen densities. The effects of the density and the loading conditions...
Optically transparent poly(methyl methacrylate) (PMMA)-based blends with significantly enhanced mechanical and shape memory properties have been successfully prepared via in-situ formation of micro-scale polylactide stereocomplex crystallites (sc-PLA) in the PMMA matrix in this work. To achieve this goal, a certain content of poly(l-lactide) (PLLA) was firstly melt-blended with PMMA to obtain completely...
We report sequential self-assembly of low molecular weight asymmetric star-like polymers from nanometric spherical micelles (core diameter 8–12 nm) to colloidal spherical superstructures (d > 500–1000 nm) in aqueous media, as directed by quadruple hydrogen bonding moieties activated by solvent exchanges. The molecules consist of a rigid asymmetric steroidal cholic acid (CA) core, whose hydroxyl...
Triple-shape memory polymers (triple-SMPs) have one permanent and two temporary shapes, which enable more complex actuation than traditional dual-SMPs. This work reports a novel polyolefin elastomer (POE)/stearic acid (SA) composite with excellent triple-shape memory and dual-responsive properties. SA displays two well-separated thermal transitions when melt-blending with POE, and is capable of memorizing...
Development of ionically crosslinked superabsorbent polyacrylic acid (PAA) self-healing hydrogels using trivalent aluminum ions was investigated. The PAA hydrogels exhibited excellent self-healing behavior depending on the amount of the aluminum within the matrix. The migration of these ions within the polymer matrix was responsible for the physical crosslinking of the hydrogel and the origin of self-healing...
The development of highly functionalized porous materials for protein separation is important for biotech processes. We report the preparation of highly porous polytriazole with sulfonic acid functionalization. The resulting ion exchange membranes are selective for protein adsorption. The starting material was a hydroxyl-functionalized polytriazole, which is an advantageous platform for further modification...
A rigorous model is developed to predict the configurations of the branched polymers formed by the copolymerization of linear monomers in the presence of multifunctional branching units. Conventional studies on the configuration of branched polymers generally consider the statistical properties of the growth of only one element or polymerization from one component (e.g., dendrimers, hyperbranched,...
We propose here a liquid foam templating route using microfluidic techniques to produce biobased monodisperse chitosan foams from aqueous chitosan solutions which are stabilized with a biobased sugar surfactant. The foaming solution contained 1.5 wt % chitosan and was stabilized by 0.1 wt % surfactant. We show how microfluidics allows for the generation of bubble sizes from 200 μm to 800 μm with the...
We report on the phase separation behaviors of polymerization mixtures containing a polylactide macro-chain transfer agent (PLA-CTA), styrene, divinylbenzene, hydroxyl-terminated PLA (PLA-OH), and a molecular chain transfer agent which enable the ability to tune the pore size of a cross-linked polymer monolith in a facile manner. Cross-linked monoliths were produced from the mixtures via reversible...
The concept of a Structurally Tailored and Engineered Macromolecular gel (STEM gel) is presented. A STEM gel is comprised of a network with latent initiating sites allowing for the post-synthesis, spatially specific modification of the matrix. A direct synthetic method was employed and photo-active STEM gels based on (meth)acrylates were synthesized by free radical copolymerization of different monomers,...
Polyelectrolyte multilayers gain their importance from their applicability to a wide variety of functional building blocks. The ability to create these multilayers as laterally nano-patterned films, which has only been scarcely investigated so far, augments the functionality of the multilayer and makes it valuable for applications that require nanoscale features or periodic arrangement, such as photonic...
Herein, we aim to develop a simple method for the fabrication of well-ordered nanoporous materials from polystyrene-block-poly(dimethylsiloxane) (PS-PDMS) diblock copolymer. By taking advantage of the intrinsic strong segregation strength between PS and PDMS, gyroid-structured PS-PDMS can be simply acquired from initially lamellae-forming PS-PDMS (i.e., PS-PDMS with almost equal volume fractions for...
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.