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 structures of polyethylene filaments prepared by crystallization from solution in extensional flow at different crystallization temperatures as well as of annealed and zone-drawn samples have been characterized by means of X-ray diffraction methods. The lattice distortions in the crystallites of such samples are quantitatively determined for the first time. The results show that a direct correlation between the crystallite dimensions and the amount of lattice distortions on the one hand and the axial Young's modulus on the other hand can be excluded. Based on X-ray, mechanical and shrinkage investigations, some parameters of the structure of the non-crystalline regions are estimated. A structure model for the high-modulus polyethylene filaments is discussed.

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.

Fibers were produced from two commercial grade linear polyethylenes (PE) of different molecular weight by flow-induced crystallization. DSC measurements were carried out with an annealing and melting program lour melting peaks were found. The first peak, at the lowest temperature, can be identified with the melting of lamellar crystallized PE. Peak 2 corresponds to the melting of the main crystalline fraction of the fiber. and peaks 3 and 4 to the melting of constrained crystalline regions. The melting temperature depends on the molecular weight of the fiber material and on the drawing state.

Acta PolymericaVolume 36, Issue 5 p. 296-296 New Book The strength and stiffness of polymers. Hg. von ANAGNOSTIS E. ZACHARIADES und ROGER S. PORTER. Bd. 4 der Reihe „Plastics Engineering”︁. ISBN 0-8247-1846-1. New York/Basel: Marcel Dekker, Inc. 1983. X. 382 S., geb. SFr 149.– D. Zenke, D. ZenkeSearch for more papers by this author D. Zenke, D. ZenkeSearch for more papers by this author First published: May 1985 https://doi.org/10.1002/actp.1985.010360521AboutPDF 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 onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume36, Issue5May 1985Pages 296-296 RelatedInformation

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.

A literature review is presented on the methods of characterization of the mesomorphic structures occuring in solutions of cellulose and cellulose derivatives. Experiments performed by the authors with the aim to characterize the liquidcrystalline states in solutions of cellulose derivatives allow the comparative estimation of the validity of current methods and complete the experience gained with these solutions.

Using the method of hot drawing developed earlier, an attempt has been made to obtain ultra-high modulus and ultrahigh strength PE filaments from original filaments produced by the “surface growth” technique. The average tensile strength of the drawn fibers reaches 5.5 GPa and the value of modulus measured in a dead loading creep experiment is estimated to be 44 GPa. 13 % of the drawn specimens had extremely high tensile strength close to theoretical estimates. The great scatter of the tensile strength data is attributed to the kink-band formation in the specimens due to their bending during preparation or during drawing.

Acta PolymericaVolume 34, Issue 6 p. 380-380 New Book Handbook of multiphase systems. Hg. von G. Hetsroni. Washington/New York/London: Hemisphere Publishing Corporation; New York: Mcgraw-Hill Book Company 1982. XX u. 1505 S., geb. DM 187,10. D. Zenke, D. ZenkeSearch for more papers by this author D. Zenke, D. ZenkeSearch for more papers by this author First published: June 1983 https://doi.org/10.1002/actp.1983.010340618AboutPDF 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 onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume34, Issue6June 1983Pages 380-380 RelatedInformation