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Differential Scanning Calorimetry and Elasticity of Textured, Heat Set and Mechanical Strained Polylactide Multifilaments

Manich A. M., Carilla J., Miguel R. A. L., Baena B., Lucas J., Martí M., Cayuela D.

Fibres & Textiles in Eastern Europe

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2011

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Vol. 19, no. 6 (89)

22--27

EN

Industrially textured PLA multifilaments were heat set under different conditions at 110 ºC for 1 min and subjected to one cycle of deformation up to 20%. Thermal transitions of the original textured, heat set and cyclic strained filaments were measured using differential scanning calorimetry from 25 to 250 ºC. Cyclic deformation induces an endo-exo transition at peak temperatures between 55 - 60 ºC that is not observed in the original textured and heat set multifilaments. There is another endo-exo transition with peak temperatures between 67 and 72 ºC in all filaments, the intensity of which varies according to texturing conditions, heat setting and cycle strain. Texturing conditions, heat setting and cyclic strain play a role in thermal transitions, the strain at breaking and lastic properties of the filaments. The crystallinity and magnitude of the endo-exo thermal events detected by DSC are related to the strain at breaking and elasticity of polylactide textured multifilaments.

PL

Teksturowane w procesie przemysłowym multifilamenty PLA były podgrzewane w temperaturze 110 °C przez 1 minutę i poddane jednemu cyklowi 20% deformacji. Przemiany, które zaszły we włóknach były badane za pomocą różnicowej kalorymetrii skaningowej przy temperaturze od 25 do 250 °C. Stwierdzono występowanie endo-exo termicznej przemiany w temperaturze 55-60 °C, która nie występuje we włóknach nieobrobionych. Stwierdzono również występowanie kolejnej przemiany endo-exo przy temperaturze 67 i 72 °C we wszystkich filamentach o intensywności zależnej od warunków teksturowania, temperatury i deformacji, które pełnia podstawową rolę w przemianach termicznych, wydłużeniu przy zerwaniu i właściwościach elastycznych włókien. Stwierdzono ze krystaliczność i wielkość przemian endo-exo są funkcją wydłużenia przy zerwaniu i elastyczności wydłużanych włókien.

2

Tensile behaviour of acrylic fibres and yarns: influence of the textile manufacturing process

Manich A. M., Ussman M., Bosch T., Castellar de M. D.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

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2000

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z. 59

135-143

EN

Vonnel Acrylic fibres from FISIPE were submitted to textile manufacturing from row material to dyed yarns. Changes on tensile behaviour along the manufacturing process have been monitorised through viscoelastic modelling using the modified Vangheluwe model. Sonic Modulus on yarns has been also measured and differences from raw to dyed acrylic yarns can be seen and they are in accordance with changes in the model parameters.

3

Measuring flax elementarisation

Castellar de M. D., Ussman M., Bosch T., Manich A. M.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

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2000

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z. 59

211-217

EN

Flax fibres from Celitex have been obtained using a conventional line in Spain. Measurements have been made after tearing and carding. The same fibre has been processed in the Technical University of Lodz and measurements have been made also after tearing, carding and cottonized fibre. Values of fineness and length measured using Image analysis, water absorption and thermal behaviour by DSC are reported on this paper. Some relationships are studied.

4

Characterisation of polyacrylonitrile yarns by thermal analysis

Bosch T., Manich A. M., Ussman M., Carilla J.

Zeszyty Naukowe. Włókiennictwo / Politechnika Łódzka

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2000

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z. 59

145-152

EN

Six polyacrylonitrile yarns of different linear density were characterised by both differential scanning calorimetry and thermomechanical analysis. The DSC technique, when working with a sealed pan, showed a step-like change around 80°C, which was associated with a glass-transition temperature, and a small cold crystallisation peak around 200°C. The DSC thermograms, when working with perfored pans, showed a single glass transition temperature around 95°C in the cooling scan (210 -0°C) and two breaks of the slope in the range 85-105°C in the reheating curve (0-210°C). The TMA scan exhibited two thermal transitions at ≈ 95°C and ≈ 160 °C. The former was very reproducible and was identified with the step-like change observed in the DSC scan. The latter was not very reproducible and, as with the DSC exothermic peak, seemed to be affected by the linear density of the yarn.