High strength/high modulus fibres can be prepared by cold drawing of UHMW-PE gel fibres. It is shown that the crystalline order in this fibres is not perfect. The supermolecular structure is characterized by a shish-kebab morphology. Results of X-ray and mechanical investigations permit to explain the drawing process by a three-step mechanism of molecular orientation and stretching coupled with molecular and fibrillar sliding.

Nascent high-molecular-weight (UHMW) polyethylene (PE) samples of different origins show a rather high crystallinity of about 70-75% and contain both a major portion of orthorhombic extended chain crystallites and a minor portion of triclinic crystallites. The triclinic content is greater the higher the molecular weight of the sample and the higher the activity of the used catalyser. A melting/recooling treatment results in a reduction of crystallinity by about 15-25% and disappearance of the triclinic phase. Further, an irreversible conversion of nascent orthorhombic extended chain crystallites to orthorhombic folded chain crystallites of increased lateral dimensions and crystalline perfections takes place during the melting/recooling treatment. The results are compared to those obtained for lower-molecular-weight PE samples and for high-strength/modulus PE fibers of different origins.

Starting from the fundamental opportunities and regularities to produce high strength/high modulus materials from polymers, results will be presented concerning the mechanical properties and the structure formation of fibres and foils obtained by different methods of preparation as well as aspects of application. The zone-drawing of poly(ethylene terephthalate), the flow-controlled crystallization of polyethylene in solution, and the gel-spinning of ultrahigh molecular weight polyethylene will be described in detail.

The supermolecular structure of two commercial and two laboratory gel-spun/hot-drawn high-modulus polyethylene (PE) fibres is characterized using wide-angle and small-angle X-ray scattering, electron microscopy and mechanical methods. Two of these samples are composed of smooth microfibrils, while the other two materials reveal a shish kebab morphology. Crystallite sizes, lattice distortions and crystalline orientations are given. For the non-crystalline regions of smooth fibrillar fibres the contents of trapped entanglements, tie and taut-tie molecules are determined. The shish kebab materials are discussed using the crystal continuity model of Ward et al. The structural parameters are correlated with the axial Young's modulus of the samples.

The morphology of surface grown polythylene fibres before and after zone-drawing is studied by electron microscopy using various preparation techniques, mainly chlorsulfonation staining and ultra-thin sectioning. Computer processing is applied in order improve the detectability of image details. Image analysis is carried out by digital or optical diffraction. It is found that, to a first approximation, the average lateral core size of the fibrils (≈ 4 nm) remains nearly constant during drawing. This is consistent with a successive “reeling in” process of chain segments from the molten shish kebab overgrowth and from the interfibriller matrix into the extended-chain backbone fibrils. The structural data derived by electron microscopy enable us to calculate the Young's moduli of the fibres within the scope of an unidirectional fibre composite model. Comparing these estimates with the results of mechanical testing yields quite a good agreement. On the other hand, the existance of gross morphological defects like kink bands, disordered boundary regions, voids, and distortions and terminations of fibril bundles, prove to cause a considerable deterioration of the fibre properties. Die Morphologie oberflächengewachsener Polyethylenfäden vor und nach einer Zonenreckung wird elektronenmikroskopisch unter Verwendung verschiedener Präparationstechniken, hauptsächlich der Kontrastierung durch Chlorsulfonierung und der Ultramikrotomie, untersucht. Computer-Bildverarbeitung wird angewandt, um die Erkennbakeit von Abbildungsdetails zu verbessern. Die Bildanalyse wird durch digitale oder optische Beugung vorgenommen. In erster Näherung wird gefunden, daß die mittlere laterale Kerngröße der Fibrillen (≈ 4 nm) während des Reckens etwa konstant bleibt. Diese Beobachtung entspricht einem allmählichen „Auffädeln”︁ von Kettensegmenten der geschmolzen “shish kebab” -Überwachunsungen und der interfibrillären Matrix auf die gestrecktkettigen Rückgrat-Fibrillen. Die elektronenmikroskopisch gewonnenen Strukturdaten ermöglichen es, die Young-Moduli der Fasern im Rahmen eines Modells für einen gerichteten Faserverbund zu berechnen. Die Übereinstimmung dieser Abschäzungen mit den Ergebnissen der mechanischen Messungen ist gut. Andererseits zeigt sich, daß die Existenz grober morphologischer Detekte, wie Kinkbänder, fehlgeordnete Grenzbereiche, Hohlräume und Verdrehungen und Abrisse von Fibrillenbündeln, eine beträchtliche Verschlechterung der Fasereigenschaften bewirkt.

Membranes of acrylonitrile polymers formed by the so-called bicomponent principle were treated with a low temperature plasma. From transport data and by electron-microscopical investigations correlations between the parameters of plasma treatment and structural changes are derived and discussed. Plasma treatment is show to be a powerful tool of modifying the properties of PAN-membranes.

With PE gel-fibres can be achieved draw rations over 20 by cold drawing. The strength level is lower than in the case of hot drawing. First data refer to a modified deformation model of high strength fibres.

The preparation of polyethylene-surface-films on high strength polyethylene fibres is studied. The effects of the substrate and of the growth conditions on the cover morphology as well as the kinetics of the growing processes are discussed.

AbstractDie Quellung monodisperser PVC/E‐Partikeln im Weichmacher DOP wird mit einer Reihe unabhängiger Methoden untersucht. Auf Grundlage eines einfachen Diffusionsmodells werden aus viskosimetrisch an verdünnten Dispersionen bestimmten Quellungskuren Koeffizienten für die Diffusion des Weichmachers in die PVC‐Partikeln berechnet. Elektronenmikroskopische, Röntgen‐ und Lichtstreuuntersuchungen sowie eine beschriebene Druckfiltrationsmethode liefern zusätzliche Angaben zum Diffusionsmechanismus.

Under the condition of inhibited shrinking the dynamic melting and recrystallization was investigated by differential scanning calorimetry with polyethylene. The melting of regions having different order was found to be not independent.

The structure formation of polyamide 6 is explained by model experiments based on the polymorphy of the polymer.

Acta PolymericaVolume 33, Issue 1 p. 86-87 Short Communication Untersuchung zum Abbauverhalten dünner PA-6-Sphärolithfilme in einer HF-Entladung E. Schulz, E. Schulz Akademie der Wissenschaften der DDR, Institut für Polymerenchemie, DDR-1530 TeltowSearch for more papers by this author E. Schulz, E. Schulz Akademie der Wissenschaften der DDR, Institut für Polymerenchemie, DDR-1530 TeltowSearch for more papers by this author First published: January 1982 https://doi.org/10.1002/actp.1982.010330117AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume33, Issue1January 1982Pages 86-87 RelatedInformation

The film formation, annealing and drawing properties of thin films of PA-6, PETP and PA-6/PETP have been investigated by scanning electron microscopy. The film formation of unipolymer systems was found to be essentially affected by the substrate. Contrarily, in the film formation from multicomponent polymer systems the intermolecular forces of the components play the most important part and superimpose the effect of the substrate on the morphological structure being formed. Annealing of the films causes rearrangement of the morphological structure and affects the deformation behaviour.

Scanning electron microscopic investigations on the stress-break relationship of polymer bicomponent systems are described. The experiments show the mechanical properties of the samples to depend on the properties of the interface of the two polymer phases.

Acta PolymericaVolume 30, Issue 1 p. 61-62 Kurze mitteilungen REM-Untersuchungen zum Deformationsverhalten von PA-6/PETP-Bikomponentensystemen E. Schulz, E. Schulz Akademie der Wissenschaften der DDR, Institut für Polymerenchemie, DDR - 153 Teltow-SeehofSearch for more papers by this authorZ. Pelzbauer, Z. Pelzbauer Tschechoslowakische Akademie, der Wissenschaften, Institut für Makromolekulare Chemie, 16206 Prag/ČSSRSearch for more papers by this author E. Schulz, E. Schulz Akademie der Wissenschaften der DDR, Institut für Polymerenchemie, DDR - 153 Teltow-SeehofSearch for more papers by this authorZ. Pelzbauer, Z. Pelzbauer Tschechoslowakische Akademie, der Wissenschaften, Institut für Makromolekulare Chemie, 16206 Prag/ČSSRSearch for more papers by this author First published: January 1979 https://doi.org/10.1002/actp.1979.010300114Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume30, Issue1January 1979Pages 61-62 RelatedInformation