Effects of distortional components in biaxial stretching of poly (ethylene terephthalate) sheets on dimensional stability and structure

Mascia, L.; Fekkai, Zakia; Guerra, Gaetano; Parravicini, Lidia; Auriemma, Finizia

doi:10.1007/bf00356656

Cited by 4 publications

(4 citation statements)

References 25 publications

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“…In addition, crystallinity plays an important role in the shrinkage property. As the crystallite formed during stress‐induced crystallization in the drawing processing of a film increases, shrinkage is decreased 28–30. Note that the crystallinity itself does not contribute to shrinkage behavior, although the increase of crystallinity leads to more resistance to shrinkage due to reduction of amorphous regions and a formed network structure.…”

Section: Resultsmentioning

confidence: 99%

Creep and shrinkage behavior of improved ultrathin polymeric films

Higashioji

Bhushan

2002

J of Applied Polymer Sci

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Long-term creep-deformation and shrinkage characteristics of improved ultrathin polymeric films for magnetic tapes are presented. These films include poly-(ethylene terephthalate) (PET), poly(ethylene naphthalate) (PEN), and aromatic polyamide (ARAMID). PET film is currently the standard substrate used for magnetic tapes, and thinner tensilized-type PET, PEN, and ARAMID have recently been used as alternate substrates with improved material properties. The thickness of the films ranges from 6.2 to 4.8 m. More dimensional stability is required for advanced magnetic tapes, and the study of creep and shrinkage behavior is important for estimating the dimensional stability. Creep measurements were performed on all available substrates at 25, 40, and 55°C for 100 h. Based on these data, master curves were generated using time-temperature superposition to predict dimensional stability after several years. The amount of creep deformation is considerably smaller for ARAMID and tensilized-type PET than for PEN, although Standard PET shows the largest amount of creep. In addition, creep measurements under high humidity also show similar trends. Shrinkage measurements at 55°C for 100 h show that the shrinkage of ARAMID is lower than that of PET and PEN. The relationship between the polymeric structure and dimensional stability are also discussed. Based on the creep and shrinkage behavior, ARAMID and tensilized-type PET seem to be suitable for advanced magnetic tapes.

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Section: Resultsmentioning

confidence: 99%

Creep and shrinkage behavior of improved ultrathin polymeric films

Higashioji

Bhushan

2002

J of Applied Polymer Sci

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“…Many researchers have investigated how the structures of polymer films obtained by biaxial stretching vary in a number of aspects [2,3] for crystalline polymers [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27], polymer blends [28,29,30,31,32,33,34] and composites [35,36,37]. The dimensional stability is enhanced due to the increase in the degree of the stress-induced crystallinity [4], surface morphology is changed [5,6], hardness is enhanced [7], and high toughness polylactide film can be obtained by development of highly-oriented small crystallites [8] in the crystalline polymers. The mechanical property is improved in the uncompatibilized polymer blends by addition of the interfacial modifier due to suppression of the interfacial voiding [28], oxygen barrier property is improved in the multi-layered polypropylene (PP)/polyethylene oxide system [29], and microporous structure is developed in the PP/nylon 6 blends [30].…”

Section: Introductionmentioning

confidence: 99%

“…The silica nanofillers are elongated parallel or perpendicular to the deformation directions depending on the type of nanofiller [35] and biaxial stretching of a PP/clay nanocomposite results in delamination and orientation of clay stacks [36,37]. Orientation by biaxial stretching is characterized by wide-angle x-ray diffraction [4,9,10,11,12,13,14,15,16,17,28,31,32], birefringence [9,13,14,15,16,17,18,19,20], infrared spectroscopy [13,20,21,22,23], fluorescence anisotropy [24], stress-strain behavior [14,16,17,25,26,27,32,33]. Isotropic plane film can be produced by simultaneous biaxial stretching, in which films are stretched in the X and Y directions at the same time, so that the properties of the stretched specimen thus produced are isotropic in the in-plane direction [14,16,32].…”

Section: Introductionmentioning

confidence: 99%

Structural Evolution of Two-Phase Blends of Polycarbonate and PMMA by Simultaneous Biaxial Stretching

Kobayashi

Saito

2018

Polymers

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We investigated the structural evolution of the two-phase blends of polycarbonate (PC) and poly(methyl methacrylate) (PMMA) at various blend compositions by simultaneous biaxial stretching, using optical microscopy and SEM observation. The spherical PMMA domains and PC matrix of 30/70 PC/PMMA were enlarged uniformly at the all in-plane direction, while the anisotropic-shaped co-continuous structure in 50/50 PC/PMMA was deformed to a crosshatched structure by the in-plane bimodal orientation. In 70/30 PC/PMMA, the phase inversion was found to occur by simultaneous biaxial stretching; that is, the spherical PMMA domains were changed to a crosshatched matrix by the in-plane bimodal orientation due to coalescence of the PMMA domains during the stretching. Owing to the phase inversion, the surface hardness estimated by the pencil hardness test became harder, from 2B to 2H, increasing the strain from 1.0 to 2.0.

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“…This force originates from a change in entropy with length. Shrinkage arises from the disorientation of the oriented amorphous phase into the state of most random conformation [8].…”

Section: Introductionmentioning

confidence: 99%

Shrinkage Behavior of Orientedpoly(ethylene Terephthalate)

Mody¹,

Lofgren²,

Jabarin³

2001

Journal of Plastic Film and Sheeting

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The kinetics of thermal shrinkage of poly(ethylene terephthalate) films have been characterized and related to various parameters of the stretching process. Amorphous orientation functions and levels of crystallinity have been found to be of major importance to the shrinkage process. As film extension ratios increase, shrinkage behavior passes through five different regions. Shrinkage first increases with extension ratio, decreases with further extension to reach a minimum, and then increases again as extension is continued to higher levels. A schematic model has been proposed to describe molecular changes in polymer chain structures, within each of the shrinkage regions. Activation energies of shrinkage have been determined in addition to equilibrium shrinkage and shrinkage rate constants.

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Effects of distortional components in biaxial stretching of poly (ethylene terephthalate) sheets on dimensional stability and structure

Cited by 4 publications

References 25 publications

Creep and shrinkage behavior of improved ultrathin polymeric films

Creep and shrinkage behavior of improved ultrathin polymeric films

Structural Evolution of Two-Phase Blends of Polycarbonate and PMMA by Simultaneous Biaxial Stretching

Shrinkage Behavior of Orientedpoly(ethylene Terephthalate)

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