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

Fischer, Erhard W.; Fakirov, S.

doi:10.1007/bf02396639

Cited by 216 publications

(34 citation statements)

References 59 publications

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“…During the last few years several studies of this kind have been published by several authors (1)(2)(3), but dealing only with PET. PBT, also a polyester in the series of poly(n-glycol terephthalate)s (abbreviated n-GT) like PET, differs in chemical structure only by two additional CH2-groups in the diol component.…”

Section: Introductionmentioning

confidence: 98%

Small angle X-ray scattering studies of poly(ethylene terephthalate) and poly(butylene terephthalate)

Bornschlegl

Bonart

1980

Colloid Polymer Sci

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Section: Introductionmentioning

confidence: 98%

Small angle X-ray scattering studies of poly(ethylene terephthalate) and poly(butylene terephthalate)

Bornschlegl

Bonart

1980

Colloid Polymer Sci

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“…Asano and Seto [4] presented a study on drawn PET where it is shown that kinetics are very sensitive to chains orientation. Fisher and Fakirov [5] confirmed these results by WAXS measurements: quiescent crystallization could not be totally neglected during stretch blow moulding. Strain also induces crystallization of PET during shear or tension loadings.…”

Section: Introductionmentioning

confidence: 65%

Simulation of the stretch blow moulding process: from the modelling of the microstructure evolution to the end-use elastic properties of polyethylene terephthalate bottles

2010

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. Abstract The whole stretch blow-moulding process of PET bottles is simulated at the usual process temperature in order to predict the elastic end-use properties of the bottles. An anisotropic viscoplastic constitutive law, coupled with microscopic variables, is identified from uniaxial tensile tests performed at different strain rates and temperatures. The microstructure evolution is characterised by crystallinity measurements from interrupted tests and frozen samples. For each specimen tested, the Young modulus is measured at room temperature. Numerical simulations of the blow moulding process are run using the C-NEM method. A micromechanical modelling is post-processed after the simulation to predict the elastic properties. Predictions of Young modulus distributions in bottles are in agreement with the ones measured on blow-moulded bottles.

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“…7 that the gradual increase, and then decrease, in the density of the amorphous phase as a function of the anneal temperature takes place in both undrawn and drawn samples [148]. This indicates that as the crystallinity grows at the lower temperature branch of the curve a sufficient local resistance to flow is present in the amorphous phase to force a significant fraction of the chain segments to become taut and remain pinned in a stretched out configuration.…”

Section: Increased Density Of the Amorphous Phasementioning

confidence: 91%

Increased glass transition temperature in motionally constrained semicrystalline polymers

Aharoni¹

1998

Polym. Adv. Technol.

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A large number of experimental results in the literature support and illuminate a model of behavior of chains and chain segments in the amorphous phase of semicrystalline polymers connecting the elevation of the glass transition temperature (Tg) above its normal value to several kinds of motional restrictions imposed on the chains and parts thereof. Accordingly, polymer chain, chain‐segment and chain‐fragment motions of all kinds comprise one or more torsions around main‐chain bonds from one stable conformation to another, known as rotational isomerizations. When impediments are placed in front of thermal fluctuations and larger transversal and longitudinal motions of polymer chains, segments and shorter fragments in the amorphous phase, and the motions are thus restricted, the glass transition temperature is elevated relative to that of the same amorphous phase in the bulk under normal conditions. The obstructions may prevent either the onset of rotational isomerizations or of their completion once started. The completion of the torsional isomerizations and larger motions may be prevented by eliminating the free spaces necessary to accommodate the volumes of the interconverting chain fragments and segments even when they move in concert, or by preventing the creation of such free spaces. Another way to hinder the completion of such motions is by the introduction into the system of many rigid walls and other interfaces with strong attractive interactions with the polymer, that by geometrical constraints and attractive interactions suppress the rotational and larger motions and prevent their completion. Elimination of the necessary free volume is achievable by the application of compressive pressure, while the introduction of rigid attractive walls may be accomplished by the incorporation of crystallites, as in semicrystalline polymers, or by the addition of rigid finely comminuted foreign additives with very large surface areas or confining voids with high tortuosity. It is believed that motional restrictions imposed on the amorphous phase by the growth faces of polymer crystallites, especially in oriented semicrystalline polymers, are more effective than the restrictions imposed by the fold surfaces of these crystallites. The prevention of the onset of rotational isomerizations and larger motions may be achieved by stretching the polymer chains and chain segments in the amorphous phase and, by one means or another, pinning down the taut chains such that essentially all their rotational isomers are in the trans conformation: they cannot interconvert to the gauche conformation since it requires the chain’s end‐to‐end distance to decrease. Parallel alignment of relatively taut chain‐segments may impose additional geometrical restrictions on both the onset and completion of rotational isomeric torsions and, of course, on longer‐range motions. In all cases, the Tg of the motionally constrained parts of the amorphous phase, especially in semicrystalline polymers, is expected to rise. It is likely that the cha...

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

Cited by 216 publications

References 59 publications

Small angle X-ray scattering studies of poly(ethylene terephthalate) and poly(butylene terephthalate)

Small angle X-ray scattering studies of poly(ethylene terephthalate) and poly(butylene terephthalate)

Simulation of the stretch blow moulding process: from the modelling of the microstructure evolution to the end-use elastic properties of polyethylene terephthalate bottles

Increased glass transition temperature in motionally constrained semicrystalline polymers

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