Thermal transitions of polylactide false-twist textured multifilaments determined by DSC and TMA

Abstract

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

Effect of UV irradiation on thermal properties of nanocomposites based on polylactide

“…This phenomenon suggests that the presence of poly(e-caprolactone) results in the increase of the crystalline phase ratio in the sample during heating. It is known that the heat of crystallisation (DH c ) is proportional to the surface under the exotherm of crystallisation and depends on both mass of crystalline phase that is formed while the melted sample is being cooled, as well as the quality of this phase [29]. It is noteworthy that after adding poly(e-caprolactone) to polylactide, a significant increase of heat of fusion and degree of crystallinity can be observed in comparison to neat polylactide, which confirms the hypothesis that PCL is the nucleus of crystallisation.…”

Microstructure variations of polylactide fibres with texturing conditions

“…The effect of draw ratio on the differential solubility is independent of the test conditions, whereas the effect of the texturing temperature is more marked for higher testing temperatures. This means that the detection of DS 28.66 2.22 X 4.02 X 5.44 X 0.86 X X 0.17 X 2 with p val 6 10 23 and R 2 0.985 (9) differences in the microstructure between substrates due to changes in texturing temperatures can be improved at higher testing temperatures. There is no clear relationship between differential solubility and crystallinity and orientation and, hence with microstructure.…”

Synthesis of branched poly(lactic acid) bearing a castor oil core and its plasticization effect on poly(lactic acid)

“…[30][31][32][33] Figure 5 shows strain-stress curves of PLLA and PLLA/L50-blended (95:5 wt%) films. The initial elastic moduli of PLLA and the blended films were 1.8 and 1.6 GPa, respectively, indicating that the compliance was slightly improved by the addition of the branched polymer.…”