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Poly(2,2-dimethyltrimethylenecarbonate) (PDTC) and its cyclic monomer 5,5-dimethyl-1,3-dioxan-2-one (DTC) are characterised by X-ray diffraction, calorimetry, dilatometry and conformational energy calculations. Three crystalline modifications are identified for PDTC: form I from solution, form III in melt spun fibers, while form II, obtained from the melt at surprisingly small undercoolings shows...
According to previous studies, the electropolymerization of N-vinyl-2-pyrrolidone fits a cationic mechanism with grafting of the polymer onto the platinum anode.However, this article shows that the pyrrolidone substituent of N-VP is also involved in the anodic reaction in addition to the polymerizable vinyl double bond. This additional reaction in the potential range of interest was confirmed by...
Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the morphology of blends of PA1010 and polypropylene (PP) compatibilized with polypropylene grafted with glycidyl methacrylate (PP-g-GMA). It is found that the morphologies are dependent on the content of glycidyl methacrylate in PP-g-GMA and the mixing time. The size of the dispersed PP particles decreases...
The rheology, mechanical properties and microstructural development during capillary flow of maleic anhydride compatibilized polyamide 6 [PA6(MAP)] blends containing liquid crystalline polymers (LCPs) were studied by means of the capillary rheometer, tensile test and scanning electron microscopy (SEM). The LCPs used were Vectra A950, and a copolyester consisting of 60 mole percent p-hydroxybenzoic...
A general procedure was developed for the synthesis of 1,1 disubstituted electron deficient olefin monomers. The formation of the phenylselenide precursor, followed by hydrogen peroxide oxidation produced the monomers in good yields and purity. Acidic by-products of the oxidation reaction act as stabilizers to prevent polymerization of these base sensitive monomers. The dicyanoacrylate ester of...
Alternating copolyesteramides (APEA's) consisting of mixtures of 1,4-butyleneterephthalamide ester (N,N -bis(p-carbomethoxybenzoyl) diaminobutane) and 1,4-butyleneisophthalamide ester (N,N -bis(m-carbomethoxybenzoyl) diaminobutane) polymerized with ethanediol were synthesised in an ethanediol solution. The bisesterdiamides were prepared from 1,4-butanediamine and dimethyl terephthalate or dimethylisophthalate...
For moderate or high conversion copolymerization data three sorts of peculiar data points are discussed which are disadvantageous in determining the relative reactivity ratios: (a) copolymer contains an unknown quantity of homopolymer because the comonomer was fully consumed before the end of the reaction, (b) estimation error of the conversion is relatively high, (c) estimation error of the copolymer...
Size distribution in methyl methacrylate polymers containing small amounts of randomly distributed dimethacrylate units was studied as a function of branching up to the point of gelation. Size distribution was determined by size exclusion chromatography with refractive index and low angle light scattering detection as well as by dynamic light scattering. Proper handling of experimental data to get...
Cross-linking reagents, divinylbenzene (DVB) in polystyrene-type ion exchange resin precursors with chloromethyl substituents were determined by pyrolysis-gas chromatography (PY-GC) in aiding preliminary reduction of chlorine atoms in the samples. The characteristic peaks of DVB or its derivatives were completely separated on the pyrograms of the reduced precursors. The relative peak intensities...
The flow behaviour of LDPE and its blends with linear LDPE (LLDPE) chemically modified with DCP was studied as a function of blend composition and shear rate at a constant temperature using a capillary rheometer. The effect of chemical modification on the viscous and elastic properties of LDPE and two blend systems LDPE/LLDPE (80:20, 60:40) is reported. Chemical modification which is in essence...
The phase behaviour of poly(ester imide)s (PEI) based on long aliphatic diols and aminobenzoic acid trimellitimide or aminocinnamic acid trimellitimide, respectively, was investigated by means of X-ray scattering. Whereas PEI with shorter spacers form smectic LC-phases which transform into higher ordered smectic phases upon further cooling, PEI with long spacers undergo a direct phase transition...
Graft copolymerization of low density polyethylene (PE) with acrylic acid (AA), ethyl acrylate (EA) and butyl acrylate (BA) using dicumyl peroxide (DCP) as the initiator was studied using differential scanning calorimetry (DSC) under the dynamic (non-isothermal) condition and in the shear mixer of a Brabender plasticorder at 170°C (443°K). DSC studies allowed measurements of the heat of reaction...
In the present work, low conversion acrylic acid (AA)/vinyl acetate (VAc) copolymerizations were carried out in azeotropic ethanol/water solutions containing 93% in weight of ethanol. Reactivity ratios were determined by several methods and shown to be equal to r AA = 2.6 and r VAc = 0.04.
It is well known that the miscibility of dissimilar polymers with high molecular weights arises from specific interaction, such as hydrogen bonding. To discuss the influence of the interaction on a side group rotation and main chain motion of poly(methyl methacrylate) (PMMA) in PMMA/poly(vinylidene fluoride) (PVDF) blends, we investigated the dielectric loss as a function of frequency f. ...
The swelling and porosity change of the pentaerythritol triacrylate (PENTA) homopolymer and PENTA-butyl acrylate (BA) copolymers were investigated as a function of PENTA content (80, 60, 40 and 20 wt%). Polymers were synthesized by the suspension polymerization method using cyclohexanol and 2-ethylhexanol as inert diluents. The solubility parameter of poly(PENTA) (18.2 MPa 12 ) was...
Flow birefringence (FB) of polymaltotriose (pullulan) in water and in dimethylsulfoxide (DMSO) has been studied. Pullulan has a high refractive index increment (Δn/Δc) in water but in DMSO it is low. Accordingly, in water the FB of molecules is mainly determined by the macroform effect and in DMSO by the intrinsic anisotropy of polarizabilities of the polysaccharide chain. The analysis of the dependencies...
Monomer reactivity ratios in free radical copolymerization of styrene and butyl acrylate monomers at 80°C in toluene solution under reduced pressure were determined for low and high conversions. Mayo-Lewis, Finemann-Ross, inverted Finemann-Ross, Kelen-Tudos, extended Kelen-Tudos, Tidwell-Mortimer and Mao-Huglin methods for low conversion and extended Kelen-Tudos and Mao-Huglin methods for high conversion...
Medical grade poly(vinyl chloride) (PVC) sheets and tubes were surface modified by nucleophilic substitution of chlorine atoms of PVC by photoactive N,N-diethyl dithiocarbamate (DTC) in aqueous media in the presence of a suitable phase transfer catalyst (PTC) at 55°C. The modified surface was cross-linked by irradiation with u.v. light in an attempt to create a barrier for the diffusion of the plasticizer...
The numerical integration method was developed to determine the relative reactivity ratios according to the simplified penultimate model (systems with r 2 = 0). It allows one to calculate the copolymer composition for zero conversion level. This procedure was used to verify the Walling-Briggs method. For this purpose literature data for the monomer system styrene/methyl α-cyanocinnamate...
It has been found that 3-(2,4-dichlorophenylazo)-9-(2,3-epoxypropane)carbazole can act as an efficient colourant and thermal stabilizer of poly(vinyl chloride) (PVC). It hinders evolution of hydrogen chloride, thus contributing to the stabilization of the system, probably via an aromatic alkylation reaction. Preliminary kinetic analysis supports the idea that the mechanism of dehydrochlorination is...
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