A partially oriented melt-extruded PLA multifilament was false-twist textured to stabilize its structure. Conventional DSC analysis showed a relaxation peak at the end of glass transition. Simultaneous consideration of the TMA curve enabled us to evaluate both the relaxation and the cold crystallisation produced during the DSC scan. The periodic load applied during TMA experiments also enabled us to examine the evolution of Young’s modulus along the glass transition, relaxation and cold crystallisation phenomena. Increases in Young’s modulus and in enthalpy are related because of crystallisation. Texturing increased crystallinity and decreased cold crystallisation of PLA during the DSC scan.Postprint (published version

A polyester fabric has been heatset in an industrial plant over a wide range of temperatures (160-220°C) to study the influence of this variable in the modification of the fine structure produced hy this thermal treatment. For this purpose, the weft of (he fabric has been characterised through physico-chemical tests such as critical dissolution time, differential solubility and iodine sorption. The heatsetting effective temperature has heen determined by differential scanning calorimetry and the crystallinity calculated from density measurements in a density gradient column. Both parameters have been correlated. The fine structure parameters deduced from the above mentioned techniques have heen correlated with the effective temperatures of heatsetting.

Polylactide multifilament yarns were textured in order to be endowed with properties of natural staple fibre yarns for textile applications. Texturing promotes the formation of stable secondary links between the macromolecular chains. A polylactide 167/68 dtex multifilament yarn was textured under different conditions. Relaxation experiments at yield, strain softening, strain hardening and just before breaking were performed. The relaxation behaviour was studied by the application of the generalized Maxwell model. The initial stress induced when stretched, the final non-relaxed stress after relaxation and the stress relaxed at different times were determined. Variations in the relaxation behaviour were related to texturing conditions and stretching.

A merino wool top was bleached in both alkaline and acidic media, varying the hydrogen peroxide concentration in the bleaching bath. For the same peroxide concentration, bleaching in an alkaline medium leads to a whiter and more chemically attacked wool than bleaching in an acidic medium. For the same chemical attack, wool bleached in an alkaline medium is whiter than for bleaching in an acidic medium.

This work is based on the analysis of the influence of dispersing agents on the non-isothermal kinetics, thermomechanical behaviour and dispersing action of PET/TiO 2 nanocomposites. The influence of two montanic waxes and an amide wax used as dispersing agents in the nucleating effect of the nanoparticles is studied. The dispersing agents are the following: a) a partly saponified ester of montanic acids (PSEMA), b) an ester of montanic acids with multifunctional alcohols (MAWMA) and c) an amide wax based on N,N'-Bisstearoyl ethylenediamine (AW). The non-isothermal kinetics based on the Avrami method revealed that MAWMA and PSEMA favours the nucleating effect of the nanoparticles when are included in PET. Birefringence microscopy points out the good dispersing capacity of MAWMA and AW and the termomechanical analysis confirmed that the ester of montanic acids with multifunctional alcohols MAWMA shows the best dispersing properties and best promotes the nucleating effect of the TiO 2 nanoparticles when used for PET/TiO 2 nanocomposites production.