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| Derombise, Guillaume; Van Schoors, L. Vouyovitch; Klop, E. A.; Schotman, A. H. M.; Platret, G.; Davies, Peter. |
| Aramid fibres are high-performance materials proposed in geotextiles for alkaline ground reinforcement. To study their durability in such environments, accelerated ageing has been carried out at pH 9 and at pH 11 for up to one and a half years. First, the lateral and longitudinal crystallite sizes have been determined before and after ageing under these conditions by Wide-Angle X-ray diffraction. Next, the tensile fracture surfaces have been observed after different ageing times by scanning electron microscopy. Finally, molecular weight changes have been evaluated by size exclusion chromatography. This study highlights the dependence of structural changes on the ageing conditions. A structural degradation scheme is proposed. |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00065/17614/15305.pdf |
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| Derombise, Guillaume; Van Schoors, Laetitia Vouyovitch; Davies, Peter. |
| Technora fibres are high performance aramid fibres which have been used in ropes and protective clothing for many years. They are also now being proposed as geotextiles for soil reinforcement. However, there is a lack of experience on the long-term behaviour of Technora fibres in an alkaline environment (lime-treated ground.). Consequently, aging studies have been performed under different conditions (deionised water, pH9 and pH11). Hydrolytic degradation has been evaluated by FTIR, viscometry, TGA, density measurements, SEM, and by tensile measurements. Some chain degradation and finish rearrangements have been highlighted, but Technora fibres retain their mechanical properties for all the conditions considered here. |
| Tipo: Text |
Palavras-chave: Aramids; Fibres; Technora; Hydrolysis; Long-term behaviour. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00002/11289/8052.pdf |
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| Derombise, Guillaume; Van Schoors, Laetitia Vouyovitch; Messou, Marie-fleur; Davies, Peter. |
| Aramid fibers are high-performance materials which have been used in ropes and protective clothing for many years. They are also now being proposed in geo-textiles for ground reinforcement. The influence of the surface finish composition and content has been studied in the field of cables and textiles, but there is no published data concerning the effect of a finish treatment on the hydrolytic degradation. Aramid fibers with different finish contents have been aged in an alkaline environment. The degradation has been identified by FTIR, viscosimetry, TGA, SEM, and tensile tests. For Technora fibers, the presence of finish appears to limit the tensile strength loss of aramid fibers at pH 11 by limiting abrasion, as well as bulk and surface degradation. For... |
| Tipo: Text |
Palavras-chave: Aramids; Fibers; Aging; Finish; Hydrolysis. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00006/11702/8987.pdf |
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| Derombise, Guillaume; Chailleux, Emmanuel; Forest, Bertrand; Riou, Luc; Lacotte, Nicolas; Van Schoors, L. Vouyovitch; Davies, Peter. |
| Aramid fibers are today proposed in ropes and cables for marine applications. As these highly crystalline materials are loaded in tension for a longer period in seawater, their long-term mechanical behavior has to be understood. However, the response is time-dependent and exhibits a nonlinear effect with stress. In this study, two types of aramid fibers are studied: Twaron and Technora. Mechanical properties are measured using static tensile tests and creep-recovery tests. A nonlinear viscoelastic-viscoplastic model, based on the Schapery formulation, allows discriminating between the instantaneous and the time-dependent response as well as the reversible and nonreversible phenomena (plasticity). First, this procedure allows the overall mechanical behavior... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00039/15049/12604.pdf |
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