4 Conclusions - POLYTECH - ETH Zürich

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ABFIGURE 6Extrusion with filament-forming dies f1 (A) and f2 (B). Scale bar corresponds to 5 mm.The data presented further reveal that die f1 was the more efficient one in orienting theliquid-crystalline polymer, as it consistently yielded material of superior stiffness andstrength.TABLE 3 Mechanical properties of as-spun filaments produced with filament-forming dies f1 andf2. λ refers to the draw-down ratio applied.die λ diameter E σ ε- μm GPa GPa %f11.7 76 50 0.8 1.72.5 63 56 0.7 1.3f21.7 77 26 0.5 3.12.6 62 43 0.6 2.14.3 Filament-fusing DiesNext, results are presented in Figure 7 of experiments in which the above filamentformingdies f1 and f2 where employed in combination with slit dies s1 and s2,respectively (referred to as “filament-fusing” dies f1-s1 and f2-s2) in attempts to guideand at least partially fuse the filaments formed with them into liquid foils prior tosolidification. While it was pleasing to note that the foils produced were of excellentappearance and no fibrillation or splitting occurred, it was disappointing to find thatthe development of the Young’s modulus with draw-down ratio - which was highlyefficient when employing the filament-forming dies alone - was significantly lesspronounced, and essentially as observed when using the simple reference slit diesalone.-78-
f1-s11 2 4 913f2-s2A6560555045401 3 4819B656055504540E (GPa)35302520151050110 20 30 40 50 60λ (-)E (GPa)353025201510500.0 0.2 0.4 0.6 0.8 1.0W ratio(-)FIGURE 7 Top: Reflected-light optical photographs and corresponding WAXD patterns ofextrudates produced with die sets f1-s1 ( upper series) and f2-s2 ( lower series). The width of thephotographs represents 15 mm; draw-down ratios, λ, are indicated in lower right corners of the X-raypatterns. Extrusion direction and product axis are horizontal. Bottom: Development of the Young’smodulus, E, with λ (A) and width ratio, W ratio , (B; see text) of foils extruded using die sets f1-s1 ()and f2-s2 (). For comparison, data obtained for products formed with reference slit-die s1 are plottedin gray ().-79-
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Diss. ETH No. 17603Ultra-high-perfo
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«I do not propose to say much abou
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Ultra-high-performance unidirection
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Hauptketten wirken bei den Aramidfa
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Planare HochleistungsfolienWie bere
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Feuilles de polymères hautes-perfo
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1 BackgroundThe use of polymers in
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A third process for the production
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2 From Fiber to Fabric and Film and
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iaxially oriented polymer films. Su
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(often assumed to be equal to that
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expressed as: 61 21 1 El( El + Et
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The properties of such laminated st
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5 References and Notes1. Carothers,
Page 35: 68. The Composite Materials Handboo
Page 39 and 40: 1 IntroductionIt has long been reco
Page 41 and 42: - unlike the present work - focused
Page 43 and 44: allowed to evaporate under air flow
Page 45 and 46: Dynamical mechanical thermal analys
Page 47 and 48: solid-state compressed films of vir
Page 49 and 50: Following pseudo-affine orientation
Page 51 and 52: shown E-λ plots for foils with dif
Page 53 and 54: 55A B C5444333σ D (MPa)2σ D(MPa)2
Page 55 and 56: esulting thermograms are presented
Page 57 and 58: A100 μmλ = 510 2030 40 5070 90 10
Page 59 and 60: A B CD E1 cmFσ (MPa)45403530252015
Page 61 and 62: polymer foils is determined princip
Page 63 and 64: AdhesionIn order to promote adhesio
Page 65 and 66: FIGURE 14 Scanning electron microgr
Page 67 and 68: foil is shown in Figure 15B, and fo
Page 69 and 70: Small deviations from quasi-isotrop
Page 71: 56. Smith, P. ; Lemstra, P. J. J. M
Page 75 and 76: 1 IntroductionIn this chapter, effo
Page 77 and 78: TABLE 1 Young’s modulus, E, and t
Page 79 and 80: s12A-A0.50.1B-B17BAABs2BA13A-A0.1B-
Page 81 and 82: ABextruder20 mmFIGURE 4 A. Schemati
Page 83 and 84: and planar foils were tested in ten
Page 85: s11 3 10 33 120s2504540353013 1729
Page 89 and 90: 4.4 Air-gap ExtrusionIn view of the
Page 91 and 92: A100B1001010W ratio / T ratio (-)10
Page 93 and 94: ABCDFIGURE 11 A. Photographs of as-
Page 95 and 96: A70B1.2601.0500.8E (GPa)40302010σ
Page 97 and 98: Finally, the mechanical characteris
Page 99: 6 References and Notes1. Kwolek, S.
Page 103 and 104: 1 IntroductionIt was already discus
Page 105 and 106: 2 ExperimentalMaterials. The polyme
Page 107 and 108: 3 Results and Discussion3.1 Foil Ex
Page 109 and 110: 3.2 Heat TreatmentAs already demons
Page 111 and 112: Expectedly, the Young’s modulus o
Page 113 and 114: the experimentally observed angular
Page 115: 5 References1. Aoki, H. ; Onogi, Y.
Page 119 and 120: 1 IntroductionCellulose is the main
Page 121 and 122: 2 ExperimentalMaterials. The nutrie
Page 123 and 124: A0.5 mmBCFIGURE 1 Bacterial cellulo
Page 125 and 126: Finally, the test-angle dependence
Page 127: 5 References1. Meyer, K. H. ; Lotma
Page 131 and 132: 1 ConclusionsThe results presented
Page 133 and 134: 10,0001,000σ (MPa/(g/cm 3 ))100101
Page 135 and 136: 1.4 Final ConclusionIn the literatu
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precursor fibers, which, however, a
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3 References1. Gordon, J. E. Proc.
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Group for great unforgettable teamw
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4 Conclusions - POLYTECH - ETH Zürich

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