Röntgenographische Untersuchungen über das Schmelz- und Kristallisationsverhalten vom Polyterephthalsäureglykolester (PTGE)

Kilian, H. G.; Halboth, H.; Jenckel, Ernst

doi:10.1007/bf01515800

Cited by 126 publications

(16 citation statements)

References 16 publications

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“…These samples were selected as representative of the low , ' V Thus it is seen t h a t the increase in crystallite size is not appreciable in the range of T, = 105 "C t o T, = 150 "C whereas in the range of T, = 150 "C to T, = 235 "C the crystallite size increase is appreciable. KILIAN et al 2) measured the percentage crystallinity of P E T as a function of Tc, and found t h a t above T, = 145°C the crystallinity increases rapidly and reaches a maximum value a t T, = 240 "C. Our observation of the growth of crystallite size as a function of Tc agrees with the above result.…”

Section: Resultssupporting

confidence: 89%

A study of the crystallization of polyethylene terephthalate using differential scanning calorimetry and X‐ray techniques

Fielding‐Russell

Pillai

1970

Makromol. Chem.

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Differential scanning calorimetry has been used to study the kinetics of the crystallization processes of polyethylene terephthalate over a wide temperature range, 95-110°C and 230-240°C. The rates of crystallization of the two processes are in agreement with earlier dilatometric measurements. Nonintegral values of the AVRAMI exponent, n = 4.5 and n = 3.4, found for the low temperature and pre-melt processes, respectively, are not in agreement with reported values of n = 2.0 and n = 4.0 for these processes. The value of n = 4.5 for the low temperature crystallization is surprising and not easily accounted for; one possible explanation is that the time dependence of the nucleation process is greater than first order. Because of their fractionality the n values yield little information on the mechanism of crystallization. Some mechanistic information is available since the low temperature crystallization isotherms are superposable along the log-time axis, whereas the pre-melt isotherms are not.Additional X-ray data have indicated the existence of one crystalline form. The X-ray data show no significant crystallite size increase for samples crystallized at 150°C over those crystallized at 105°C. Samples crystallized a t 235°C show a larger and more ordered crystalline structure than those crystallized at 105 and 150°C.The relationship between the crystalline melting points and the temperatures of crystallization is as predicted by MANDELKERN. ZUSAMMENFASSUNG:Die Kinetik der Kristallisation von Poly(athylenterephtha1at) wurde mit einem Differentialkalorimeter in einem weiten Temperaturhereich (95-110°C und 230-240°C) untersucht. Die Kristallisationsgeschwindigkeiten der beiden Prozesse sind in Ubereinstimmung mit fruheren dilatometrischen Messungen. Die nicht ganzzahligen Werte fur den AVRAMI-Exponenten, n = 4,5 und n = 3,4 fur die Kristallisation bei niederen Temperaturen bzw. vorgeschmolzenen Proben, stimmen nicht mit den veroffentlichten Werten von n = 2,O und n = 4,O uberein. Der Wert von n = 4,5 fur die Kristallisation bei niederen Temperatusen ist uberraschend. Eine mogliche Erklarung besteht darin, die Kristallisationskeimbildung als eine Funktion hoherer Ordnuug anzunehmen. Da die n-Werte keine ganzen Zahlen sind, geben sie nur geringe Hinweise uber den Mechanismus der Kristallisation. Hinweise uber den Mechanismus geben die Isothermen der Kristallisation bei niederen Temperaturen. Diese sind entlang der log-T-Achse deckungsgleich, was fur die Isothermen der vorgeschmolzenen Proben nicht zutrifft.Zusatzliche rontgenographische Untersuchungen zeigen die Anwesenheit von nur einer Kristallform. Sie zeigen ferner keine wesentliche Zunahme der KristallitgroRe in Proben, die 263 G. S. FIELDING-RUSSELL and P. S. PILLAI bei 150 bzw. 105°C kristallisiert wurden; bei 235°C kristallisierte Proben zeigen hingegen eine besser ausgebildete und hoher orientierte Struktur als die vorgenannten.Der Zusammenhang zwischen den Schmelzpunkten der kristallisierten Proben und der Kristallisationstemperatur stimmt mit den Ergebnissen...

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Section: Resultssupporting

confidence: 89%

A study of the crystallization of polyethylene terephthalate using differential scanning calorimetry and X‐ray techniques

Fielding‐Russell

Pillai

1970

Makromol. Chem.

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“…Fig. 16a to g show the improvement of order with increasing annealing temperature [9, [29][30][31]. Some of the relevant features of the X-ray patterns will be discussed later.…”

Section: -To0000-mentioning

confidence: 97%

Structure and properties of polyethyleneterephthalate crystallized by annealing in the highly oriented state

1976

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The structure of polyethyleneterephthalate bristles drawn about five times in the amorphous state and subsequently crystallized at temperatures between 100 and 260 ~ C has been studied by means of small-angle X-ray scattering. In addition density, heat of fusion and wide-angle scattering behaviour were measured. For comparison, similar experiments were carried out with undrawn samples. The results showed that the degree of crystallinity of PET cannot be calculated from density data on the basis of a simple two-phase model, since the effective densities pc and Pa of the crystalline and amorphous regions depend strongly on crystallization and drawing conditions. With rising crystallization temperature the size of the mosaic blocks building up the crystalline layers and their longitudinal mutual order increase whereas the volume fraction of the crystalline region is only rather slightly effected by the annealing temperature. The difference between the effective density Pc and the "X-ray density" Pc of the crystalline layers is supposed to be caused by lattice vacancies in the boundaries of the mosaic blocks.

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“…For the density of the noncrystalline phase Qa in PET different values in the range between 1.333 and 1.337 Mg/m 3 are reported in the literature [16][17][18]. According to the equations (1)- (3) with 4 unknown quantities the volume ratio of the crystalline regions and the microvoids can be calculated dependent upon the density of the noncrystalline phase.…”

Section: Discussion Of Resultsmentioning

confidence: 99%

Change of structure and orientation of semicrystalline drawn poly(ethyleneterephthalate) films on simultaneous thermal and mechanical treatment

Scherz

Hinrichsen

1985

Colloid & Polymer Sci

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Highly oriented semicrystalline PET films are exposed to uniaxial statical load both parallel and perpendicular to the preferential orientation direction at various temperatures.The loading of the specimens parallel to the preferential orientation direction leads to an increase in orientation of the chain segments within the amorphous interlayers and to a decrease of density of the amorphous regions which in combination with a rise of the microvoid volume ratio effects a significant increase of the mean square density fluctuation. Thereby chain segements may emerge from the crystalline regions and may pass into the amorphous interlayers.

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Röntgenographische Untersuchungen über das Schmelz- und Kristallisationsverhalten vom Polyterephthalsäureglykolester (PTGE)

Cited by 126 publications

References 16 publications

A study of the crystallization of polyethylene terephthalate using differential scanning calorimetry and X‐ray techniques

A study of the crystallization of polyethylene terephthalate using differential scanning calorimetry and X‐ray techniques

Structure and properties of polyethyleneterephthalate crystallized by annealing in the highly oriented state

Change of structure and orientation of semicrystalline drawn poly(ethyleneterephthalate) films on simultaneous thermal and mechanical treatment

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