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Photochromic poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) fibers were prepared by electrospinning from a solution of copolymer and ester-functionalized nitrospiropyran (SPEST) molecules. The surface and internal features of the electrospun (ES) fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and wide-angle X-ray diffraction...
The effects of incorporated amorphous poly(dl-lactide) (PDLLA) on the isothermal crystallization and spherulite growth of crystalline poly(l-lactide) (PLLA) and the structure of the PLLA/PDLLA blends were investigated in the crystallization temperature (T c ) range of 90–150°C. The differential scanning calorimetry results indicated that PLLA and PDLLA were phase-separated during crystallization...
PVC/CaCO 3 polymer nanocomposites of differing compositions were produced using a two-roll mill and compression molding. The morphology was observed using transmission electron microscopy, and the static and dynamic mechanical and fracture properties determined. The presence of nanometer-sized CaCO 3 particles led to a slight decrease in the tensile strength but improved the impact...
Poly(N-isopropylacrylamide)-b-[poly(ethyl acrylate)-g-poly(2-(diethylamino)ethyl methacrylate)] (PNIPAM-b-(PEA-g-PDEAEMA)) double hydrophilic graft copolymers were employed to prepare stable colloidal gold nanoparticles in situ with controllable size in aqueous media without any external reducing agent. PDEAEMA side chains served as reduction agent and stabilizer and PNIPAM segment acted as a hydrated...
Two series of hyperbranched polymers (HP), polyurethanes and polyureas, with aromatic and aliphatic structures, are synthesized in one-pot method using commercially available monomers. The obtained HP samples were characterized by 1 H Nuclear Magnetic Resonance (NMR) spectroscopy, Gel Permeation Chromatography (GPC), Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis...
A systematic procedure has been developed to construct a relaxed dense-phase atomistic structure of a complex amorphous polymer. The numerical procedure consists of (1) coarse graining the atomistic model of the polymer into a mesoscopic model based on an iterative algorithm for potential inversion from distribution functions of the atomistic model, (2) relaxation of the coarse-grained chain using...
The qualitative and quantitative thermal analysis of biodegradable poly(lactic acid) PLA is presented. The glass transition, melting process, and heat capacity of a semi-crystalline poly(lactic acid) are studied utilizing the differential scanning calorimetry and temperature-modulated DSC. The mobile amorphous fraction, W a degree of crystallinity, W c and rigid-amorphous fraction,...
The focus of this study was the effect of spatial confinement on the development of nucleating agent-induced β phase polypropylene (PP) in the dynamically vulcanized thermoplastic elastomers (TPVs) based on dynamically vulcanized PP/ethylene-propylene-diene rubber (EPDM) blend. The melting behaviors, crystalline structures and the morphologies of the blends were studied by differential scanning calorimetry...
By reducing the attraction between the platelets of octadecylammonium chloride modified montmorillonite (OMMT-C18) via pre-intercalation of maleated polypropylene (MAPP), OMMT-C18 was exfoliated in thermoplastic polyurethane (TPU) matrix during melt-mixing. Wide angle X-ray diffraction, transmission electron microscopy and thermogravimetric analysis were used to investigate the microstructure of TPU...
Since its discovery in 2001, copper catalyzed azide–alkyne ‘click’ chemistry has been extensively used in polymer chemistry to modify polymeric materials and create advanced polymer structures by efficient coupling reactions. Surprisingly, the contribution of this Huisgen cycloaddition reaction to industrially important commodity polymers, prepared by step-growth polymerization, was not existing until...
Poly(ɛ-caprolactone)-block-poly(butadiene-co-acrylonitrile)-block-poly(ɛ-caprolactone) triblock copolymer was synthesized via the ring-opening polymerization of ɛ-caprolactone with dihydroxyl-terminated butadiene-co-acrylonitrile random copolymer. The amphiphilic block copolymer was used to toughen epoxy thermosets via the formation of nanostructures. The morphology of the thermosets was investigated...
A water-soluble supramolecular structured photosensitive initiator (SSPI) was developed by the supramolecular self-assembling between the photosensitizer (xanthene dye) and the initiator (Complex A). The structure of SSPI was characterized by static and dynamic fluorescence quenching method. The photolysis properties of SSPI in the film were evaluated. The photopolymerization of AM and bis-AM in the...
Amphipathic hyperbranched polymeric thioxanthone (TX) photoinitiators (AHPTXs) were synthesized by introducing TX, and polyethylene glycol monoethylether glycidyl ether (E-PEO), which contained short poly (ethylene oxide) (PEO) chain, into periphery of hyperbranched poly(ethylene imine) (HPEI), as well as low-molecular weight analogue 2-(2-hydroxy-3-(methyl(2,3,4,5,6-pentahydroxyhexyl)amino)propoxy)...
Polymer nanocomposites can exhibit superior multi-functional properties if they possess phase separated morphology at the nanoscale. Despite the huge potential of these materials, there are several fundamental issues including the ultimate microstructures, which need to be resolved to tailor different physical and mechanical properties required for specific applications. A ‘ternary nanocomposites’...
The effects of annealing on the structure and mechanical properties of mesomorphic isotactic polypropylene have been investigated using wide-angle and small-angle X-ray scattering and rheo-optics in addition to tensile tests. Young's modulus of mesomorphic phase was estimated to be 5GPa using Takayanagi model. The α-crystallitic iPP prepared by annealing the quenched mesomorphic iPP was transparent...
In this paper we describe the production of a polypropylene (PP)/carbon nanofibre (CNF) nanocomposite, and subsequent characterisation of the structure and properties of the nanocomposite material at various stages of blending. Dispersion of the CNF throughout the matrix PP was monitored by scanning electron microscopy (SEM), and analysis of the lengths of the individual CNF was estimated using dynamic...
Hyper-branched polyethylenimine grafted polycaprolactone block mono-methoxyl poly (ethylene glycol) copolymer (hy-PEI-g-PCL-b-mPEG) was obtained through the conjugation of mPEG–PCL with hyper-branched PEI (hy-PEI) based on the Michael addition. mPEG–PCL was synthesized by ring-opening polymerization of caprolactone using mPEG as the initiator. Compared earlier syntheses, this method offered a reduced...
High molecular weight perfluorocyclobutyl-containing polybenzimidazoles (PFCB–PBI) were synthesized from 4,4′-((1,2,3,3,4,4-hexafluorocyclobutane-1,2-diyl)bis(oxy))dibenzoic acid (PFCB diacid) and 3,3′,4,4′-tetraaminobiphenyl (TAB) in phosphorous pentoxide/methanesulfonic acid (PPMA). PPMA was used as a reaction medium to replace PPA due to the higher monomer solubility. High molecular weight polymer...
Different Ethylene–Propylene Diene Monomer (EPDM) elastomers with different crosslink densities have been processed in order to evaluate the influence of gamma irradiation on their properties. In the case of a major phenomenon of chain scissions, the consequences are a decrease in the modulus and also a decrease in the strain at break. This decrease in the strain at break is opposite to what is expected...
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