Kristallisation von Polycarbonaten. I. Lichtmikroskopische Untersuchungen
01 Jan 1964-Macromolecular Chemistry and Physics (John Wiley & Sons, Ltd)-Vol. 75, Iss: 1, pp 112-121
TL;DR: The rate of spherulite growth, measured by means of polarisation microscope, depends on the chemical structure of the polycarbonate as mentioned in this paper, which is a relatively high tendency to crystallize.
Abstract: Polycarbonate auf der Basis 4,4′-Dioxy-diphenyl-2,2-propan, 4,4′-Dioxy-diphenylmethan und 4,4′-Dioxy-diphenyl-sulfid kristallisieren mit athermischer Keimbildung aus der Schmelze spharolithisch. Es wurden verschiedene morphologische Strukturen beobachtet.
Die lichtmikroskopische Bestimmung der Spharolith-Wachstumsgeschwindigkeit last eine unterschiedliche Kristallisationsneigung der betrachteten aromatischen Polycarbonate erkennen. Danach zeigt das Polycarbonat auf Basis 4,4′-Dioxy-diphenyl-2,2-propan ein stark gehemmtes und verzogertes Kristallisationsverhalten, wahrend die Polycarbonate auf Basis 4,4′-Dioxy-diphenyl-methan und 4,4′-Dioxy-diphenylsulfid als relative kristallisationsfreudig zu bezeichnen sind. Als Ursache fur das unterschiedliche Kristallisationsverhalten wird der verschiedenartige molekular Aufbau diskutiert.
Polycarbonates from 4,4′-Dioxy-diphenyl-2,2-propan, 4,4′-Dioxy-diphenylmethan, and 4,4′-Dioxy-diphenyl-sulfid crystallize from the melt with spherulitic structure and athermal nucleation. Depending on crystallization conditions different morphological textures were observed.
The rate of spherulite growth, measured by means of polarisation microscope, depends on the chemical structure of the polycarbonate. The crystallization of polycarbonates from 4,4′-Dioxy-diphenyl-2,2-propan is hindered by the spacefilling isopropyl-group. On the other hand, polycarbonates from 4,4′-Dioxy-diphenyl-methan and 4,4′-Dioxy-diphenyl-sulfid have a relatively high tendency to crystallisation.
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TL;DR: In this paper, the growth rates of spherulites were measured in poly(p-phenylene sulphide) crystallized from the melt and the quenched glass over the temperature range 100°C-280°C, possibly the most extensive overall range yet reported for any polymer and, as such, most propitious for study of regime III crystallization.
178 citations
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TL;DR: In this paper, a chemical reaction occurs during the mixing process between the salt and the ester links of the macromolecules, which produces ionic end-groups which are responsible for the acceleration of the crystallization rate.
90 citations
TL;DR: In this article, differential scanning calorimetry studies of the temperature and molar mass dependences for the primary and secondary crystallization behavior of bisphenol A polycarbonate was performed.
Abstract: In this paper, we report differential scanning calorimetry studies of the temperature and molar mass dependences for the primary and secondary crystallization behavior of bisphenol A polycarbonate ...
78 citations
TL;DR: The morphology of glassy amorphous thin polycarbonate film cast from solution is affected by thermal treatments as mentioned in this paper, which results in an increase in the size of the ordered regions, nodules, up to several hundred Angstroms.
Abstract: The morphology of glassy amorphous thin polycarbonate film cast from solution is affected by thermal treatments. Annealing above 80° C and below Tg results in an increase in the size of the ordered regions, nodules, up to several hundred Angstroms. The crystallization process from the glass, taking place at 145° C, is divided into three major steps. At first the nodules merge into patches which aggregate to form lamellar planar structures. In some cases the planar structures are well-formed single crystals. Following this, spherulitic arms develop from the planar structures as centers. These arms at first consist of aggregates of large nodules which recrystallize to form lamellae; the final morphology is spherulitic in nature. The effect of film thickness and of several substrates on the morphology has been observed. Applying stress at room temperature to the crystalline film results in a breaking up of the lamellae into small blocks.
73 citations