Crystallization behaviour of poly(phenylene sulphide)/polystyrene blend
TL;DR: In this paper, the authors investigated the crystallinity of poly(phenylene sulphide) (PPS) blended with polystyrene by an X-ray diffraction technique for samples made by three mixing techniques viz. powder blending, melt blending and solution blending.
About: This article is published in European Polymer Journal.The article was published on 1987-01-01. It has received 14 citations till now. The article focuses on the topics: Phenylene & Crystallinity.
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TL;DR: In this article, the authors investigated the miscibility and domain structure of poly(vinyl alcohol)/poly (vinylpyrrolidone) (PVA/PVP) blends by high-resolution solid-state 13 C nuclear magnetic resonance methods.
84 citations
TL;DR: In this paper, the effect of CaCO3 on polypropylene (PP) crystallization behavior and the modification of structure was investigated using X-ray diffraction and optical microscopy.
Abstract: The effect of CaCO3 on the crystallization behaviour and the modification of structure in polypropylene (PP) has been investigated using X-ray diffraction and optical microscopy. The crystallization half time deduced from spherulitic growth rate was found to vary sharply and decreased considerably from 5–6 min for pure polymer to less than 2 min in the presence of CaCO3. The ultimate spherulite size also decreased considerably for PP containing CaCO3. Its dependance on composition however, showed a plateau region at about 10–15 wt % of additive. The intensities of certain reflections especially the 130 and 040 of the α phase were greatly affected by the presence of CaCO3 and large variations in the crystallinity (Ci) values were observed with composition. The ratio of intensities of 130 and 040 reflections and theCi revealed a maximum at a certain concentration of CaCO3. The above results can be explained on the basis of nucleation and preferential growth of the α phase of PP crystallites.
46 citations
TL;DR: In this paper, a mixture of polyphenylene sulfide (PPS) with a commercial, wholly aromatic, liquid crystal copolyesteramide (Vectra-B950) has been prepared by meltblending.
Abstract: Blends of polyphenylene sulfide (PPS) with a commercial, wholly aromatic, liquid crystal copolyesteramide (Vectra-B950) have been prepared by meltblending. The crystallization behavior of neat and blended PPS has been studied by differential scanning calorimetry (DSC), under both non-isothermal and isothermal conditions. It has been found that blending PPS with Vectra-B leads to an increase of the temperature of non-isothermal crystallization and to a pronounced acceleration of the isothermal crystallization, without any reduction of the degree of crystallinity. All these effects have been found to occur independent of the Vectra-B concentration, within the investigated range (2 to 20%, w/w). The results have been interpreted in terms of an incrased nucleation density of the blends, probably due to heterogeneous substances, initially present in the Vectra-B bulk, which dissolve to saturation in the PPS phase, during melt-blending.
43 citations
TL;DR: In this article, the crystallization of polyethylene oxide/polymethyl methacrylate (PEO/PMMA) blends was investigated with respect to composition and different casting solvents.
38 citations
TL;DR: In this article, the authors investigated the properties of poly(vinyl alcohol)/poly(methacrylic acid) complexes and polyvinyl alkaline/poly(acrylic) blends using high-resolution 13C solid-state NMR method.
Abstract: Miscibility of poly(vinyl alcohol)/poly(methacrylic acid) complexes and poly(vinyl alcohol)/poly(acrylic acid) blends is investigated by high-resolution 13C solid-state NMR method. Observed 13C spectra are discussed in terms of hydrogen-bonding effects on chemical shift. The results indicate that poly(vinyl alcohol) and poly(methacrylic acid) are intimately mixed on a scale of 20–30 A due to intermolecular hydrogen bonding to form equimolar-ratio complexes. For the poly(vinyl alcohol)/poly(acrylic acid)=1/1 blend, the two polymers are also miscible, the crystalline phase of PVA is destroyed completely and no detectable domain can be observed for the blend on a scale of 20–30 A. Poly(vinyl alcohol)/poly(acrylic acid)=2/1 and 1/2 blends are homogenous on a scale of 200–300 A, but heterogeneous on a smaller scale.
27 citations
References
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TL;DR: In this article, the authors present an analysis of macromolekularen MEhrkomponentensystems using computer assisted IR and FTIR spectrometers, under the condition that spectral superposition is valid.
Abstract: Die Einfuhrung computerunterstutzter IR- und FTIR-Spektrometer hat die Moglichkeiten der qualitativen und quantitativen Analyse von makromolekularen Mehrkomponentensystemen erheblich erweitert. Wenn die Forderung der spektralen Superposition erfullt ist, last sich mit Hilfe gespeicherter Standardspektren der Komponenten durch Differenzspektrometrie die Zusammensetzung eines Systems ermitteln. Da diese Forderung sehr oft nicht erfullt ist, wahlt man fur die Differenzspektrometrie eines Systems aus n spektral definierten Komponenten n Punkte aus dem empirisch zu ermittelnden optimalen Bereich im Innern des (n-1)-dimensionalen Gibbsschen n-Ecks. Bei realen Polymergemischen mit kristallisierbaren Komponenten ist deren Kristallinitatsgrad niedriger als in den ungemischten Polymeren; dies ist wahrscheinlich auf gegenseitige Durchdringung der nichtkristallinen Bereiche zuruckzufuhren. Hochgefullte Kunststoffe lassen sich differenzspektrometrisch noch gut identifizieren, wenn der Fullstoff monodispers ist (Zahnzemente). Organisch gefullte Werkstoffe mit niederem Bindemittelanteil (Hartfaserplatten mit Holzschliff) lassen sich nur dann differenzspektrometrisch identifizieren, wenn die charakteristischen Absorptionen des Bindemittels in Bereichen liegen, in denen der Fullstoff nicht stark absorbiert. —Artefakte konnen ein differenzspektrometrisches Ergebnis verfalschen. Ursachen und Auswirkungen von Artefakten werden diskutiert.
The introduction of computer-assisted IR and FTIR spectrometers has greatly enlarged the possibilities of qualitative and quantitative analysis of macromolecular multi-component systems. By using the digitally stored standard spectra of the components of a system the composition of this system can be evaluated under the condition that spectral superposition is valid. Since this condition is frequently invalid it is preferable, for the analysis of a system with n spectroscopically defined components, to choose n compositions within an optimal range within the (n — 1) dimensional Gibbs diagram. In real polymer blends with crystallizable components the degree of crystallinity of these components will be lower than in the unmixed polymers. This is probably due to the mutual interpenetration of the noncrystalline ranges of the different polymers. Highly filled materials can be identified quite reliably when the filler or reinforcing material is monodisperse. This ist the case, e.g., with dental cements (fillings). Organically filled construction materials with low concentrations of binder (e.g., fiber board) can be identified by difference spectrometry when the characteristic absorptions of the binder will not coincide with strong bands of the filler. — Artefacts may falsify a difference spectrum. Origins and consequences of artefacts will be discussed.
5 citations
TL;DR: In this article, the crystalline content in high pressure compacted polymeric powders has been investigated as a function of molding pressure, and it has been noted that the crystallinity Cp varied with the pressure as [C 0 − βPα] where α and β were material dependent constants.
Abstract: The crystalline content in high pressure compacted polymeric powders has been investigated as a function of moulding pressure. It has been noted that the crystallinity Cp varied with the pressure as [C0 — βPα] where α and β were material dependent constants. There also appears a correlation between α, β, and an empirically defined factor which is related to the glass transition temperature, melting point, and compressive yield strength for all the polymers studied. The results have been discussed in terms of various processes taking place during the high pressure compacting step.
Der Kristallinitatsgrad in unter hohem Druck gepresten Polymerpulvern wurde in Abhangigkeit vom Presdruck untersucht. Es ergab sich, das die Kristallinitat Cp vom Druck in Form der Funktion [C0 — βPα] abhangt, wobei α und β materialabhangige Konstanten darstellen. Weiterhin wurde eine Korrelation zwischen α, β und einem empirisch bestimmten Faktor erhalten, die mit der Glastemperatur, dem Schmelzpunkt und der Kompressionsfliesgrenze fur alle untersuchten Polymere verbunden ist.
Die Ergebnisse wurden unter Berucksichtigung verschiedener Prozesse, die wahrend des Hochdruckpressens stattfinden, diskutiert.
5 citations