Innovative Bio-based Poly(Lactic Acid)/Poly(Alkylene Furanoate)s Fiber Blends for Sustainable Textile Applications

Abstract

This work aims at producing and investigating, for the first time, the microstructural and thermo-mechanical properties of fibers constituted by poly(lactic acid) (PLA)/poly(alkylene furanoate)s (PAFs) blends for textile applications. Two different PAFs have been investigated, i.e., poly(octylene furanoate) (P8F) and poly(dodecylene furanoate) (P12F), which have been blended with PLA in different concentrations and spun through a lab-made wet spinning device. The microstructural investigation of the fiber cross-section evidenced domains of PAFs homogeneously dispersed within the PLA matrix. The immiscibility of the produced blends was also suggested by the fact that the glass transition temperature of PLA was unaffected by the presence of PAF. The thermal stability of PLA was not substantially influenced by the PAF content, whereas the water absorption tendency decreased with an increase in P12F fraction. The mechanical properties of PLA/P8F blends decreased with the P8F amount, while for PLA/P12F fiber blends the stiffness and the strength were approximatively constant by increasing the P12F content. The drawing process, performed at 70 °C and with two different draw ratios, brought an interesting increase in the mechanical properties of PLA fibers upon P12F introduction. These promising results constitute the basis for future research on these innovative bio-based fibers.

Statistical Modeling and Optimization of the Drawing Process of Bioderived Polylactide/Poly(dodecylene furanoate) Wet-Spun Fibers

“…Therefore, the drawing process is very promising to obtain high-performance PLA/PDoF fibers. This is evident despite the high standard deviation of some results, which stems from the non-uniform fiber diameters, the porous microstructure, and the non-complete solvent removal, as explained in our previous work [ 24 ]. More specifically, the selected spinning parameters could be more suitable for one composition (e.g., PLA/PDoF) and less for the other (e.g., PLA), and the residual solvent can affect the two polymer phases in a different way, which could partially explain the large standard deviations and the non-significant difference in elastic moduli of the as-spun fibers.…”

“…The solvent was evaporated for 24 h in air and then the fibers were stored in a desiccator. Further details of the production process are reported in our previous work [ 24 ]. Table 1 reports the values of tensile elastic modulus (E) and strain at break (ε B ) of the produced filaments, as resulted from the characterization performed in our previous work [ 24 ].…”

“…Draw ratios of 50% and 150% were selected, as these values did not lead to fiber breakage at the selected drawing speeds of 50 mm/min and 100 mm/min. Drawing temperatures were chosen according to DSC data on as-spun filaments of PLA and PLA/PDoF blends reported in previous work (see Figure 1 ) [ 24 ]. A temperature of 40 °C was chosen as it is in between the T g of PDoF, i.e., −5 °C [ 20 ], and that of the PLA used in this work, i.e., 55 °C [ 24 ].…”

“…Drawing temperatures were chosen according to DSC data on as-spun filaments of PLA and PLA/PDoF blends reported in previous work (see Figure 1 ) [ 24 ]. A temperature of 40 °C was chosen as it is in between the T g of PDoF, i.e., −5 °C [ 20 ], and that of the PLA used in this work, i.e., 55 °C [ 24 ]. Moreover, a temperature of 70 °C was chosen as it lays in between the T g of PLA and the melting temperature of PDoF, i.e., 103 °C.…”

“…Despite the potentialities and the versatility of PAFs, very few publications dealing with PLA/PAF blends can be found in the open scientific literature. Our group has recently developed blends of PLA and PAFs with different alkyl chain lengths (i.e., with a number of carbon atoms in the diol from 2 to 12), prepared in the form of films and fibers through solvent casting, spinning, and electrospinning [ 23 , 24 , 25 , 26 , 27 ]. Although these blends are generally immiscible, the results showed that the addition of 5–10 wt% of any of the considered PAFs to PLA remarkably increases the strain at break and the fracture toughness, especially for cast films.…”