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For in-depth analyses of polyolefin microstructures, we have installed the MW-specific light scattering (LS) and viscosity detectors into a home-built hybrid GPC–TREF instrument. Data processing capabilities were developed for this triple-detector system to determine (1) polymer long chain branching (LCB) distribution across the GPC-determined molecular weight distribution (MWD) curve, (2) the GPC-M...
The crystallization behavior of a linear polyethylene has been studied using conventional isothermal hot stage microscopy and with the Ding–Spruiell method of rapid cooling. When studied at rapid cooling rates the polymer generates its own pseudo-isothermal crystallization temperatures, in agreement with Ding–Spruiell's studies on other systems, permitting experiments to be carried out isothermally...
Nonlinear optical polymers with high glass transition temperatures were prepared by covalent functionalisation of polymaleimide copolymers with hydroxyalkyl chromophores via the Mitsunobu reaction. The polymaleimides were obtained by radical polymerisation of maleimide with 4-phenylstyrene (PM1), indene (PM2) or 1-adamantylmethacrylate (PM3). Glass transition temperatures in the range of 222–288°C...
The phase structure of the miscible blends of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV) has been analyzed through DSC measurements and the observations of spherulite growth. Melting temperature and spherulite growth rate of the blends changed depending on the blend composition, which indicates that the extent of phase segregation increases as the HV content...
We report the dynamic infrared spectroscopic studies on segmented poly(urethaneurea). In this study, we take into consideration not only the dynamic dichroic difference spectra but also the dynamic average absorption spectra, in order to detect dynamic change in concentration of hydrogen bondings. As a result, the similarity in shapes of spectra between the static and dynamic dichroic difference and...
To investigate the potential of a fully aromatic, amorphous thermotropic liquid crystalline polyester (CPHNA60) as the in situ reinforcement component for poly(ethylene terephthalate) (PET) fibers, blends containing up to 10wt% of CPHNA60 were prepared, characterized and spun into fibers. DSC measurements of the blends revealed a nucleating effect of CPHNA60 and rheology investigations showed a decreased...
Simple shear of end-tethered Nylon 6–clay nanocomposites and the preservation of these effects into the crystalline state is reported. Typical conditions leading to mesoscopic (clays) and molecular (polymer chains) orientation of these systems at relatively low shear rates and at temperatures immediately above the nominal melting point showed a morphological change proportional to the shear time in...
To elucidate the emergence of liquid crystal (LC) domains during polymerization induced phase separation in a polymer dispersed liquid crystal (PDLC), numerical simulation has been performed by incorporating the kinetics of crosslinking reaction into the time-dependent Ginzburg–Landau (TDGL-Model C) equations in conjunction with the combined Flory–Huggins (FH)/Maier–Saupe (MS) free energies. The TDGL-Model...
A copolymer of the water-soluble hydrophilic monomer N,N-dimethylacrylamide and of the practically water-insoluble hydrophobic t-butylacrylamide was synthesised in aqueous solution in the presence of sodium dodecylsulfate (SDS) micelles. Its behaviour in dilute aqueous solution was compared to the behaviour of its respective counterpart with practically the same composition, prepared under homogeneous...
The study was carried out on nanocomposites consisting of nanoscopic silica fillers embedded in polyamide 6. Various composite systems were prepared through in situ polymerisation, with different elementary particle diameters and filler contents as variables. The morphological investigation demonstrated the non influence of the particle presence on the crystalline phase of such composites. The introduction...
The changes in the dynamic structure during temperature-induced phase transition in poly(vinyl methyl ether) (PVME)/D 2 O solutions and gels in a broad range of concentrations (c=0.1–30wt%) and crosslinking densities, respectively, were studied by 1 H NMR methods. Similar behaviour was found both for linear and crosslinked systems, indicating the formation of compact globular-like...
Compatibilization of blends of an immiscible polymeric system consisting of poly(butylene terephthalate) (PBT) and poly(phenylene ether) (PPE) by a set of low molecular weight epoxy, varying in chain flexibility and functionality, was studied in terms of morphology and mechanical properties. Evidences, such as reduction of epoxide peak in FT-IR spectra and viscosity and glass transition temperatures...
We discuss here the first two stages of the tenter-frame film manufacturing process for HDPE, viz. (a) the extrusion of the polymer onto a cooled cast roll (base sheet) and (b) drawing along the machine direction (MD) using several sets of rolls (referred to as machine draw orientation (MDO) sheet). The structure–property relationships are analyzed for a single resin when the cast-roll temperature,...
Acetylene-containing polymers, obtained by the radical polymerization of 4-substituted aromatic enynes, were subjected to the thermal crosslinking reaction on the basis of the reactivity of the acetylene moieties. The crosslinking occurred from ca. 140°C to give an insoluble product. The crosslinking was supposed to be the irreversible reaction of the acetylene moieties to give new conjugated structure...
Blends of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN) have been analyzed in terms of their crystal structures and morphologies. Wide angle X-ray diffraction (WAXS), small angle X-ray diffraction (SAXS), and density measurements were performed on blend samples crystallized quiescently and on samples strain induced crystallized. For blends quiescently crystallized isothermally,...
Various rheological properties have been studied for two kinds of low-density polyethylenes (LDPEs): one is produced by tubular process (tubular LDPE) and the other by vessel process (vessel LDPE). The latter shows smaller g′-parameter, the ratio of intrinsic viscosity to that of linear polyethylene. It was found that both LDPEs exhibit marked strain hardening behavior, i.e. upturn departure from...
Three series of polydiphenylsiloxane (PDPS)-containing diblock copolymers were synthesized with controlled molecular weight and composition by sequential addition of the corresponding comonomers through a living anionic polymerization. These copolymers included poly(diphenylsiloxane-b-dimethylsiloxane) (PDPS/PDMS), poly(diphenylsiloxane-b-methylphenylsiloxane) (PDPS/PMPS), and poly(diphenylsiloxane-b-methyltrifluoropropylsiloxane)...
Healing of interfaces of amorphous and semi-crystalline poly(ethylene terephthalate) (PET) was carried out above and below the (bulk) glass transition temperature (T g ) of the samples (two amorphous and two semi-crystalline polymers of different molecular weights). The lap-shear strength of the amorphous/amorphous interface was found to develop without discontinuity in the vicinity of the...
Reactive blending of polyamide 6 (PA) with polyethylene (PE) having reactive site, maleic anhydride (MAH), and PE having glycidyl methacrylate (GMA) units was carried out using a gram-scale mixer at 240°C. Morphology of reactive blend was studied by light scattering and transmission electron microscopy (TEM). TEM observation revealed that Y-shape PA–PE graft copolymers in situ-formed in PE-rich system,...
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