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Multiwalled carbon nanotubes (CNTs) filled polymer composite based on polycarbonate (PC) and polyethylene (PE) was fabricated by shear controlled orientation in injection molding (dynamic samples) and conventional injection molding (static samples). The morphological observation by scanning electronic microscope (SEM) indicated that PC phase in situ generated more and finer microfibrils in the dynamic...
By adding a small amount of acid treated multi-walled carbon nanotubes (MWCNTs) into poly(p-phenylene sulfide)/polyamide 66 (60/40w/w) blends, the morphology was found to change from sea–island to co-continuous structure. As the MWCNT content was increased, the morphology came back to sea–island but with increased domain size. It was very interesting to note that the MWCNTs were found to be selectively...
This study aims to assess the relative influence of microstructure, molar mass and morphology on the local α relaxation of isotactic polypropylene (iPP). For that purpose, three families of samples have been prepared. The Ziegler–Natta type provides a wide molar mass range where both the isotactic average length (n 1 ) and the nature of the isotacticity interruptions change according to chain...
A series of novel low-dielectric constant (low-κ) polyimide (PI) composite films containing the SBA-15 or the SBA-16-type mesoporous silica were successfully prepared via in situ polymerization and following thermal imidization. Their morphologies, dielectric constants, and thermal and dynamic mechanical properties were investigated. It is found that the dielectric constants of the composite films...
The microstructure of Triton X-100 (TX-100)/poly (ethylene glycol) (PEG) complex has been investigated by fluorescence resonance energy transfer (FRET), dynamic light scatter (DLS), freeze-fractured transmission electron microscopy (FF-TEM) and 1 H NMR technology. The nonionic surfactant TX-100 and pyrene are employed as energy donor and acceptor respectively, and the average distance between...
The composites of polypyrrole (PPy) and poly(vinyl alcohol) (PVA) with aligned 3-dimensional (3D) microstructures have been fabricated via vapor deposition polymerization (VDP) of pyrrole onto the microstructured composites of PVA and FeCl 3 (PVA–FeCl 3 ) formed by directional freezing. In these composites, the microstructures of PVA act as the frameworks and the conducting polymer...
Free-standing polypyrrole films have been stretched or cold rolled to produce uniaxially and biaxially textured films. The oriented films show an increase in conductivity up to 3× when compared to unprocessed films, due to polymer chain alignment. Highly anisotropic active stress and strain are observed for the textured films, with up to 7× larger active strains transverse to the orientation direction...
The relationship between microstructure and toughness of biaxially stretched semicrystalline polyester films was investigated. Optically transparent films were prepared by simultaneous biaxial stretching of melt-cast sheets near the glass transition temperature. Copolyesters of polyethylene terephthalate (PET) with different compositions of two diols: ethylene glycol (EG) and cyclohexane dimethanol...
Dispersion, distribution, and alignment of carbon nanotubes (CNT) in polycarbonate (PC) composites are quantified by means of statistical analysis of transmission electron microscopy (TEM) images. The analysed images originate from samples with 0.875 and 2wt% CNT, processed by compression and injection moulding, respectively. The composites exhibit different microstructures with different electrical...
Segmented polyurethane block copolymers were synthesized using 4,4′-methylenediphenyl diisocyanate (MDI) and 1,4-butanediol (BDO) as hard segments and various soft segments derived from poly(hexamethylene oxide) (PHMO) and poly(dimethylsiloxane) (PDMS)-based macrodiols and mixtures thereof. The microstructure and degrees of phase separation were characterized using a variety of experimental methods...
The microstructures of lamellae-forming diblock copolymer melts confined in nanorod arrays are investigated using the real-space self-consistent field theory. The nanorod array leads to the incomplete confinement at each direction so that the confinement-dimension is fractional between zero and two. This incomplete confinement can yield a rich variety of mixture microstructures by varying its fractional...
This article describes the focused ion beam (FIB)-tomography as a high-resolution three-dimensional (3D) technique to study the morphology of polymer/clay nanocomposites. To establish the structure–property relationship of such composite material, it is very important to visualize the 3D-structure and distribution of clay particles in the polymer matrix. The sequential two-dimensional sectioning by...
We investigate the gradual changes of the microstructure of two blends of high-density polyethylene (HDPE) and polyamide 6 (PA6) at opposite composition filled with increasing amounts of an organomodified clay. The filler locates preferentially inside the polyamide phase, bringing about radical alterations in the micron-scale arrangement of the polymer phases. When the host polyamide represents the...
Two polypropylene homopolymers, samples A and B, synthesized with heterogeneous Ziegler–Natta catalysts, are studied in this work. Both samples show improved impact properties at low temperature than isotactic PP. Particularly, sample B exhibits better toughness, higher molecular weight and slight lower flexural properties than sample A. Then, these two samples were fractionated into six fractions...
Large amount of work has been reported on the annealing of polypropylene (PP) and the related changes in mechanical properties. However, the structure–property correlations and the physical origin of annealing induced microstructural evolution are still not very clear. In this work, taking β-form PP (β-PP) as example, the microstructural changes induced by annealing were investigated from macromolecular...
Commercial polyethersulfone (Udel ® 1800) based on 4,4′-dihydroxy-2,2-diphenylpropane (bisphenol-A) and dichlorodiphenylsulfone was post-sulfonated using trimethylsilyl chlorosulfonate under mild conditions. The partially sulfonated polyethersulfones were investigated by 1 H and 13 C NMR in their acid and/or sodium salt form. Several 13 C NMR signals could be assigned...
The dependence of the fluorescence quenching of electropolymerized poly(aniline-co-m-chloroaniline) with polymer composition has been investigated. Fluorescence emission in polyaniline is quenched when the polymer is oxidized (brought to emeraldine state); the copolymers exhibit decreasing quenching as chloroaniline contents increases. Quenching shows a strong decrease in the presence of 0.1% m-chloroaniline...
A predictive multiscale computational framework has been proposed to study the viscoelastic properties of polymeric materials. Using the Inverse Boltzmann Method, both the static structures and dynamic behavior of all-atomistic models of polymers can be reproduced by a simple coarse-grained model, which bridges the scale from nano to meso. On this coarse-grained level, the entangled network of polymer...
The influences of free volume and temperature on the viscoelastic properties of polycarbonate (PC)/multi-walled carbon nanotube (MWNT) composites were investigated by positron annihilation lifetime spectroscopy (PALS) and dynamic mechanical analysis (DMA). Three methods, including PALS, DMA and differential scanning calorimetry were used to determine the glass transition temperature (T g )...
One of the most promising aspects of the anodic aluminium oxide (AAO) template is the ability to generate a variety of different hierarchical one-dimensional (1D) polymer morphologies with structural definition on the nanometric scale. In-situ polymerization of monomers in reduced space of porous AAO template nanocavities can give rise to the direct production of versatile polymer nanostructures....
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