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A molecular dynamics (MD) study was performed to analyze the enthalpy of mixing between poly(vinyl chloride) (PVC) and various aliphatic polyesters. The enthalpy of mixing was calculated from the computed cohesive energy densities of: (1) pure PVC; (2) aliphatic polyesters with a molar ratio of CH2/COO groups from 2 to 14; and (3) mixtures of these components. In order to validate the calculation...
Co-continuous morphologies in a blend of poly(ether–ester) and polystyrene break up into a droplet/matrix morphology when subjected to a shear flow in a rheometer with a cone–plate configuration and are therefore not stable under shear. It is shown that the capillary number at these flow conditions is too small to maintain stable extended structures that are necessary for a co-continuous morphology...
The influence of solvent and temperature on the miscibility of poly(methyl methacrylate)/poly(vinyl acetate) (PMMA/PVAc) was investigated. Experiments using differential scanning calorimetry (DSC) and viscometry were performed. LCST curve was determined by measurements of transmitted light intensity against temperature, at several compositions of PMMA/PVAc, 15/85, 25/75, 50/50, 75/25 and 85/15. It...
Dielectric spectroscopy is a technique which is still hardly used for on-line characterization of polymers. In this article we describe its use at medium frequencies (between 10Hz and 1MHz) for on-line monitoring of the morphology of polymer blends during extrusion. A sheet extrusion die containing two electrodes, made it possible to perform the dielectric on-line analysis.A blend of a thermotropic...
The synthesis and polymerisation of 2,3-diazanorborn-5-enes are reported. Reaction of 2,3-diazanorborn-5-ene derivatives 6–9 with molybdenum based initiators 1–3 leads, in most cases to ring opening metathesis polymerization. By contrast, monomers 6–9 are not polymerized by ruthenium based initiator 4. The polymers were characterized by NMR, GPC and MALDI-TOF mass spectrometry and were found to have...
Poly(2-trimethylsilyl-2-propyl methacrylate-co-γ-butyrolactone-2-yl methacrylate) was synthesized and evaluated as a chemically amplified resist for ArF lithography. The polymer has excellent transmittance at 248nm and also has a good transmittance at 193nm. In addition, the polymer possesses good thermal stability up to 200°C, whereas in the presence of an acid the cleavage of the 2-trimethylsilyl-2-propyl...
Macromonomer with styrenic polymerizable group was synthetized by anionic polymerization of ethylene oxide initiated by a mixture of potassium p- and m-vinylbenzyl alcoholate. The corresponding alcohol was prepared by modified two-step method described by Bamford et al. (Polymer 1973;14:330) using vinylbenzyl chloride as a starting material. Emulsion polymerization of styrene was carried out in the...
Nylon-610 membranes were prepared at 25°C by direct immersion of various dope solutions into either formic acid/water or 1-octanol bath. Depending on the dope and bath conditions, the precipitated membranes demonstrated characteristics derived from crystallization and/or liquid–liquid phase separation during the precipitation process. As a good dope solution was immersed in a harsh bath, e.g., water,...
The influence of two natural terpene resins on the morphology, phase structure and isothermal crystallization process of iPP was investigated by optical (OM) and electron microscopy (SEM) and differential scanning calorimetry (DSC). It was found that in dependence on temperature, composition and chemical nature of the resin, one, two or three phases can be present. The isothermal spherulite growth...
The intensities and lifetimes of positrons annihilating in low and high density poly(ethylene) (LDPE and HDPE) were measured. As expected the orthopositronium (oPs) pick-off lifetime and intensity increases with temperature; the relative values of the intensity are consistent with differential scanning calorimetry (DSC) results. Two other components with shorter lifetimes were deconvoluted from the...
The photopolymerization of a diacrylate monomer with an N-aliphaticmaleimide as the photoinitiator has been investigated by photo-differential scanning calorimetry (photo-DSC), real-time infrared (RTIR) spectroscopy, and real-time UV (RTUV) spectroscopy. Photo-DSC exotherm results for relatively thick films (∼150μm) showed an increase in the polymerization reactivity (R) up to a concentration of only...
Processing of a SMA/PMMA blend through a capillary results in a complex change of phase behaviour with deformation rate. Both deformation induced demixing and remixing are observed. This complex phase behaviour as a function of apparent shear rate, is in qualitative agreement with experimental and theoretical results found for a polystyrene/poly vinyl methyl ether (PS/PVME) blend (Fernandez ML, Higgins...
Mobility and orientation of amorphous chains in cold drawn films of isotactic polypropylene (PP) are studied by 2H-NMR as a function of the annealing temperature. It is shown that the deformation is not affine. The relaxation of amorphous chains in materials annealed with free and clamped ends appears respectively at T*≈Tg+50°C and at Tαc≈80°C. Above these transition temperatures, corresponding to...
A new transamidation reaction, between an aliphatic secondary amide and an aromatic nitrile, leading to an aromatic amide and an aliphatic nitrile is described in this article. The best conditions have been established: 300°C, no solvent, 2h, 1wt.% PPA as catalyst. Yields were found to be independent of the nature of para substituents, but strongly decrease for an ortho substituted compound. NMR studies...
In 1964 Kovacs (Kovacs, AJ, Transition vitreuse dans les polymères amorphes. Etude phénoménologique. Fortschr Hochpolym-Forsch 1964;3:394–507) published a paper in which he analyzed structural (volume) recovery data in asymmetry of approach experiments. Kovacs used a parameter referred to as τ-effective (τeff) which is defined in terms of the volume departure from equilibrium δ as τeff−1=−1/δdδ/dt...
The change in mechanical properties induced by irradiation of electron (2MeV), proton (10 and 20MeV), He2+ (20 and 50MeV), and 220MeV C5+ ions were studied for polymer films of polyethylene (PE), bis-phenol A based polysulphone (PSF) and polyethersulphone (PES). There is no difference between the irradiations of proton and electron in the mechanical properties for PE compared by absorbed dose. On...
Copolymers of n-butylvinylether (BVE) and n-octadecylvinylether (OVE) with styrenesulphonate (SS) were obtained by micellar copolymerization in the presence of the cationic detergent CTAB. The polymerization reaction proceeds mainly in the domain of the hydrophobe-containing cationic micelles, to which SS and the initiator are attracted electrostatically. The monomer distribution along the polymer...
In order to enhance the rate of crystallisation of polyhydroxybutyrate (PHB), and copolyhydroxybutyrate-co-valerate (CHB/HV), the effect of various seeding agents was investigated. Solid mixtures of PHB containing either saccharin or phthalimide, and a blend of CHB/HV with PHB were prepared. The effect of these materials as nucleating agents was compared with a commercial nucleating agent, boron nitride...
A novel type of poly(urethane–imide) was prepared by a reaction of a polyurethane prepolymer and a soluble polyimide containing hydroxyl functional group. Polyurethane prepolymer was prepared by a reaction of polyester polyol and 2,4-tolylenediisocyanate and then end-capped with phenol. Soluble polyimide was prepared by the two-step synthesis from 2,2′-bis (3,4-dicarboxyphenyl)hexafluoropropane dianhydride...
The carbonyl groups in eight high-performance polyaryl-etherketones and -thioetherketones were reduced to methylene linkages in high yield by treatment at room temperature with triethylsilane in a mixture of trifluoroacetic acid or methanesulphonic acid with either dichloromethane or chloroform. When the starting polyketone is readily-crystallizable, the reduced polymer also tends to crystallize during...
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