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This work reports on the preparation of UV-light responsive nanocapsules based on cross-linked polyamide, obtained by miniemulsion interfacial polymerization. The photo-triggered E-Z transition of azobenzene moieties of the polymer backbone enabled controlled release of encapsulated molecules. Appropriate selection of emulsion conditions allowed tailoring size distribution of the resulting nanocapsules...
Polypropylene (PP) foams are important in various industrial applications due to their unique mechanical and electrical properties. However, fabrication of microcellular PP foams is still limited because of polymer's rheological properties. In this work, the influence of rheological properties and the layer confinement effect on the microcellular morphology of foam/film structure and the mechanical...
Oxidative polymerization of pyrrole on the surface of platelets of graphene oxide (GO) was demonstrated to generate polypyrrole/GO (PPy/GO) hybrid assemblies. The polymerization reactions were performed in GO acid dispersions using ammonium persulfate (APS) as an oxidant. Model kinetic reactions were carried out by 1H NMR spectroscopy with APS at low temperatures. Evidence was found for an increase...
In this paper, crosslinking process and thermo-mechanical properties of epoxy materials containing diglycidyl ether bisphenol-A (DGEBA) as the epoxy resin and JEFFAMINE® D-230 polyoxypropylenediamine as the hardener have been studied using molecular dynamics simulation. An algorithm to create the crosslinked epoxy has been developed, and the crosslinking process is monitored. The simulation results...
This article describes the preparation of hybrid gradient porous surfaces by using the breath figures approach. In a first step gradient porous surfaces were created from polymeric blends consisting of a linear polystyrene as major component and amphiphilic copolymers of poly(styrene-co-acrylic acid) as minor component. THF was used as solvent conducting to porous surfaces with a gradual variation...
In this paper we report a facile process to introduce ionic interactions to polypropylene (PP) based on Zn-neutralization and amine modification reactions of maleic anhydride grafted PP (PP-g-MAH) for the preparation of high melt strength PP (HMSPP). A series of PP ionomers with different structures and ionic properties were synthesized via the choice of the pendant groups, and their effects on the...
A series of cardo poly(ether ketone imide)s (PEKI-C) containing large-volume bulky phthalide groups were prepared by aromatic nucleophilic substitution reaction of commercially available phenolphthalein and 4,4′-bis(4-fluorophthalimido)diphenyl ether/4,4′-difluorobenzophenone. The glass transition temperatures (Tgs) increased from 221 to 278 °C with increasing the content of 4,4′-bis(4-fluorophthalimido)diphenyl...
We propose a microscopic structural deformation model of hard elastic polypropylene (HEPP) during uniaxial stretching using time-resolved simultaneous wide- and small-angle X-ray scattering measurements. It is found that ‘double’ yielding point, characteristic of HEPP in the tensile deformation, corresponds to the formation of the voids with a fine chain slip within the lamellae, followed by the fragmentation...
A novel macromonomer composed of poly(α-l-glutamic acid) was used as a stabilizer for dispersion polymerization of styrene in DMF–water medium with AIBN initiator, giving narrowly-distributed functional polystyrene particles on which the poly(α-l-glutamic acid) was grafted. The resultant particles had 0.54–2.12 μm in size and 0.2–2.6 residue/nm2 in surface density and showed a pH-responsive colloidal...
The electromechanical properties of graphene/gelatin hydrogel composites were investigated under the effects of graphene surface area, electric field strength and temperature towards bio-actuator applications. The highest surface area of an embedded graphene (MG; grade M) in the gelatin hydrogel composites induced the highest dynamic modulus (G′) under applied electric field. The 0.1 vol% graphene...
Silica/PS and silica/PMMA heterodimers were obtained in very good yields using 80 nm silica particles first functionalized with a polymerizable alkoxysilane and then used as seeds for the emulsion polymerization of either styrene or methyl methacrylate. Aiming at a one-pot and scalable process, a commercial silica sol was used and the grafting reaction of silica with the functional silane was directly...
In this work, the regular usage of conventional dynamic mechanical analyzer (DMA) has been extended through the characterization of rubber elasticity and dynamic viscoelasticity of the TPV composites based on natural rubber, ethylene octene copolymer and carbon black (NR/EOC/CB). Two independent theoretical approaches viz. rubber index and damage parameter, have been adopted in order to evaluate the...
Condensation on the surfaces of single-walled carbon nanotube (SWCNT) buckypaper and polymer single crystal-decorated buckypaper was monitored in situ using an environmental SEM (ESEM). Water vapor was pumped into the chamber, and backside cooling was used to control sample surface temperature. In this way, condensation could be imposed on the sample. It was found that, due to the different wetting...
A unique crystalline signature not reported previously for atactic poly(methyl methacrylate) PMMA was observed in the X-ray diffraction of single wall carbon nanotubes (SWNT)/PMMA bucky papers indicating ordered PMMA wrapping on SWNT. This ordered PMMA wrapping was not observed in few wall carbon nanotubes (FWNT)/PMMA and multiwall carbon nanotube (MWNT)/PMMA bucky papers.
With the emergence of scientific interest in graphene oxide (GO) in recent times, researchers have endeavored to incorporate GO in thermoset polymeric matrix to develop composites with extraordinary set of properties. The current state of research in graphene/thermoset polymer composites is highlighted here with a focus on the role of interface in dictating the overall properties of the composites...
Here, the synthesis of a galactosylated amphiphilic copolymer bearing rhodamine (RhB) moieties and its use for the preparation of polymeric fluorescent nanoparticles for potential applications in therapy and diagnosis are described.To do this, firstly, a fluorescent derivative of α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) was synthesized by chemical reaction with RhB, and with polylactic acid...
In this article, a multiscale modeling technique is developed to determine the effective elastic moduli of CNT-reinforced epoxy composites containing either well-dispersed or agglomerated carbon nanotubes (CNTs). Two aspects of the work are accordingly examined. In the first, molecular dynamics simulations are carried out to determine the atomic-level elastic properties of a representative volume...
Stable polypropylene, PP – low molecular weight modifier systems were prepared in order to analyze the influence of the physical state of the amorphous phase on thermo-mechanical properties. The modifier was introduced into solidified material by diffusion to the amorphous phase regions. The change of state of stress of the transmitters connecting adjacent crystals caused by substantial increase of...
Among various polymer wastes, management of crosslinked plastics is a major environmental problem requiring a solution. Among various crosslinked plastics, recycling of crosslinked polyethylenes is of a great importance due to the presence of a three-dimensional network. To solve this problem, novel environmentally friendly technologies for decrosslinking of the crosslinked polymers are developed...
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