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We investigated the effect of silica nanoparticles on the mechanical property and fracture toughness of two epoxy systems cured by Jeffamine D230 (denoted J230) and 4,4′-diaminodiphenyl sulfone (denoted DDS), respectively. Toughening mechanisms were identified by a tailor-loaded compact tension method which quantitatively recorded the deformation of a damage zone in the vicinity of a sub-critically...
A polybutadiene 19 -block-poly(ethylene oxide) 94 (PB–PEO) has been modified by free-radical additions of 2-ethylhexanethiol, 1-decanethiol, and 1-dodecanethiol separately to the PB block. The block copolymers were characterized by DSC, SAXS, XRD and AFM measurements. Above the melting temperature of PEO, PB–PEO showed hexagonal morphology having PB cylinders in the PEO matrix. The...
The dispersion of magnetic nanoparticles (NPs) in homopolymer poly(methyl methacrylate) (PMMA) and block copolymer poly(styrene-b-methyl methacrylate) (PS-b-PMMA) films is investigated by TEM and AFM. The magnetite (Fe 3 O 4 ) NPs are grafted with PMMA brushes with molecular weights from M=2.7 to 35.7kg/mol. Whereas a uniform dispersion of NPs with the longest brush is obtained in...
A new polyradical containing polyallene backbone and stable pendant nitroxyl radicals was synthesized using 4-hydroxyl-2,2,6,6-tetramethylpiperidine as starting material. Firstly, a new allenyl ether monomer, 4-allenyloxyl-2,2,6,6-tetramethyl piperidine was prepared by 2 steps. Next, BPO initiated the traditional free radical polymerization of 4-allenyloxyl-2,2,6,6-tetramethyl piperidine at 100°C...
We present a systematic theoretical investigation of star-like polymers of various architectures near adsorbing surface, using a new numerical self-consistent mean field theory. The comparison of the experimentally reported adsorption profiles with the predictions of our method shows excellent agreement. The study of the structural properties of the formed brushes indicates that as the number of branches...
We report the synthesis of higher-molecular-weight hyperbranched polyethylenes containing cross-linking structures via chain walking copolymerization of ethylene with a diacrylate cross-linker, 1,4-butanediol diacrylate, using a Pd-diimine catalyst, [(ArNC(Me)–(Me)CNAr)Pd(CH 3 )(NCMe)]SbF 6 (Ar=2,6-(iPr) 2 C 6 H 3 ). The hyperbranched chain topology of these...
In this paper, we compare two procedures for the synthesis of palladium (Pd)/polycarbonate (PC) nanocomposites as well as their morphological, optical, thermal and electrical properties. Pd nanoclusters were produced by the reduction of palladium chloride using a variation of Brust's method. Discrete Pd nanoclusters of ∼15nm size were formed in the absence of PC in the reaction mixture (ex situ method)...
In this paper, we report novel crosslinking systems for surfactant-free artificial latexes based on anhydride-containing polymers. Surfactant-free latexes with average particle diameters of about 150nm and a ζ-potential of −70mV have been successfully obtained from anhydride-containing polymers with various T g s and polarities, including poly(octadecene-alt-maleic anhydride) (POMA) and maleinized...
Acrylamido boronic acids are important building blocks for functional polymers but suffer from poor synthetic strategies and unwanted polymerisation. A two-step deprotection of pinacolato methacrylamido phenylene boronic esters to generate 2-, 3- and 4-methacrylamido phenylboronic acids in good yield and purity is reported. Boronic acid containing methacrylamido monomers are now available in good...
Thermal- and photo-oxidation processes occurring in poly(1,4-butylene terephthalate) (PBT) were investigated and compared in order to find out potential dissimilarities in the oxidation pathways of this polymer. The oxidized compounds were analyzed by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Applications of MALDI to the study of polymer photo- and...
Destruction and formation of the carbon nanotube network in polymer melts have been investigated by a combination of conductivity spectroscopy and dynamic-mechanical analysis for polycarbonate (PC) containing multiwalled carbon nanotubes. The combined setup allows simultaneous time-resolved measurements of electrical conductivity, dielectric permittivity and dynamic shear modulus. Furthermore, well-defined...
Single molecule force spectroscopy (SMFS) is a powerful means in studying the intramolecular and intermolecular interactions in polymer and supramolecular systems, thus opening new horizons for nanomechanic chemistry. This feature article concerns mainly how to employ AFM-based SMFS to obtain some of the important information which is not available by conventional characterizing methods, including...
Atom transfer radical polymerization (ATRP) of acrylonitrile (AN) with ethyl 2-bromoisobutyrate (EBiB) as the initiator was firstly approached in the absence of any ligand in three novel ionic liquids, 1-methylimidazolium acetate ([mim][AT]), 1-methylimidazolium valerate ([mim][VT]) and 1-methylimidazolium caproate ([mim][CT]), respectively. All the polymerizations in the ionic liquids proceeded in...
Temperature-responsive hollow poly(N-isopropylacrylamide) (PNIPAAm) microspheres were prepared by a two-stage distillation precipitation polymerization to afford a core–shell microspheres with subsequent removal of poly(methacrylic acid) (PMAA) core. PMAA@PNIPAAm core–shell microspheres were synthesized by the second-stage polymerization of NIPAAm in the presence of PMAA as core with N,N′-methylenebisacrylamide...
Twin-screw extrusion using a co-rotating Berstorff ZE25 extruder was applied to disperse multi-walled carbon nanotubes (MWNT) in poly(lactic acid) (PLA). The masterbatch dilution technique was used whereas four different masterbatches were produced under variation of MWNT content, screw profile, temperature profile, and rotation speed which then were diluted to composites with 0.75wt% MWNT under varied...
The effects of flow-altering inserts and mold cavity geometry on the mechanical properties of an injection molded liquid crystalline polymer were studied to produce parts with properties approaching macroscopically isotropic state. By inserting fine metal mesh barriers to the gates of the mold cavities, a large number of highly oriented microstreams are produced. After their creation these highly...
The enthalpy relaxation of bisphenol A (BPA) and copolycarbonates of BPA and trimethylcyclohexylidene bisphenol (TMC) is studied using low heating rate DSC measurements. The glass transition behavior of the polycarbonates shifts to higher temperatures with increasing TMC content. The relaxation behavior of BPA is characterized by large and narrow peaks whereas the copolycarbonates exhibit a broader...
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