In response to increasing environmental concerns, significant efforts have been made to reduce our reliance on fossil fuel-based plastics, driving the development of sustainable alternatives such as polyhydroxyalkanoates (PHAs). This study investigates the processing of various PHAs into fibres, focusing on their morphological, thermal, and mechanical properties. Different PHAs were spun into fibres at a 15% (w/v) concentration using wet-spinning techniques. Among the PHAs studied, commercially available PHBHHx, used as a reference, exhibited spongy morphology in the fibres and demonstrated thermal vulnerability due to its rapid degradation. Blended fibres showed enhanced morphological and mechanical properties compared with neat fibres. In Fourier-transform infrared spectroscopy (FTIR), no differences were observed between the unprocessed polymers and the wet-spun polymeric fibres, indicating that the wet-spinning process did not affect the molecular structure of the polymers. Thermal and mechanical evaluations confirmed the miscibility between the polymers in the blends. Overall, these results highlight, for the first time, the successful production of wet-spun fibres from two modified P(3HB) variants, individually, in combination with each other, and in blends with the well-established commercial PHA, PHBHHx. However, this study also underscores the need to optimise feed rates to enhance fibre production efficiency and mechanical strength, thereby broadening their potential for various applications.

In response to the increasing environmental concerns, significant efforts have been made to reduce the reliance on fossil fuel-based plastics, driving the development of sustainable alternatives such as polyhydroxyalkanoates (PHAs). This study investigates the processing of various PHAs into fibres, focusing on their morphological, thermal, and mechanical properties. Different PHAs were spun into fibres at a 15% (w/v) con-centration using wet spinning techniques. Among the PHAs studied, commercially available PHBHHx, used as a reference, exhibited a spongy morphology in the fibres and demonstrated thermal vulnerability due to its rapid degradation. Blended fibres showed enhanced morphological and mechanical properties compared to neat fibres. In Fouri-er-transform infrared spectroscopy (FTIR), no differences were observed between the unprocessed polymers and the wet spun polymeric fibres, indicating that the wet spinning process did not affect the molecular structure of the polymers. Thermal and mechanical evaluations confirmed the miscibility between the polymers in the blends. Overall, these results highlight the potential of polymer blending to enhance fibre functionality and broaden their application potential. However, the study also empha-sizes the need to explore optimized feed rates to improve fibre production efficiency and increase their resistance, to enlarge their suitability for various applications.

Developing sustainable textile finishes that enhance moisture management and breathability remains a significant challenge in designing high-performance apparel. In this study, we propose an eco-friendly coating strategy utilizing an aqueous dispersion of poly(3-hydroxybutyrate)-diol (PHB.E.0), a member of the polyhydroxyalkanoate (PHA) family. This coating was applied to woven polyester (PES) and cotton (CO) fabrics using a low-impact spray-coating technique, aiming to improve functional properties while maintaining environmental sustainability. This solvent-free process significantly reduces chemical usage and energy demand, aligning with sustainable manufacturing goals. Successful deposition of the coating was confirmed by scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), elemental (C/O) analysis, and thermogravimetric analysis (TGA), which also revealed substrate-dependent thermal behaviour. Wettability, water absorption, and permeability tests showed that the coated fabrics retained their hydrophilic character. PHB.E.0 coatings led to a significant reduction in air permeability, particularly after hot pressing at 180 °C, from ≈670 to ≈171 L·m⁻² s⁻¹ for PES and from ≈50 to ≈30 L·m⁻²·s⁻¹ for CO, without compromising water vapor permeability. All coated samples maintained high breathability, essential for wearer comfort. These results demonstrate that PHB.E.0 coatings enhance wind resistance while preserving moisture vapor transport, offering a sustainable and effective solution for functional sportswear.

Developing sustainable textile finishes that enhance moisture management and breathability remains a significant challenge in designing high-performance apparel. In this study, we propose an eco-friendly coating strategy utilizing an aqueous dispersion of poly(3-hydroxybutyrate)-diol (PHB.E.0), a member of the polyhydroxyalkanoate (PHA) family. This coating was applied to woven polyester (PES) and cotton (CO) fabrics using a low-impact spray-coating technique, aiming to improve functional properties while maintaining environmental sustainability. This solvent-free process significantly reduces chemical usage and energy demand, aligning with sustainable manufacturing goals. Successful deposition of the coating was confirmed by scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), elemental (C/O) analysis, and thermogravimetric analysis (TGA), which also revealed substrate-dependent thermal behaviour. Wettability, water absorption, and permeability tests showed that the coated fabrics retained their hydrophilic character. PHB.E.0 coatings led to a significant reduction in air permeability, particularly after hot pressing at 180 °C, from ≈670 to ≈171 l/m²/s for PES and from ≈50 to ≈30 l/m²/s for CO, without compromising water vapor permeability. All coated samples maintained high breathability, essential for wearer comfort. These results demonstrate that PHB.E.0 coatings enhance wind resistance while preserving moisture vapor transport, offering a sustainable and effective solution for functional sportswear.

Functionalized wet-laid nonwovens were developed from recycled cotton fibres, including spinning process residues (SPRs) and cotton fabric scraps (CFSs), blended with refined bleached eucalyptus kraft pulp (BEKP), demonstrating the valorisation of textile waste into high-performance materials. A two-step surface functionalisation strategy was applied, combining spray deposition of a polyamide-amine wet-strength resin with padding using carnauba wax, polyurethane dispersion and their combination. SEM and ATR-FTIR analyses confirmed successful functionalization of the cellulosic nonwovens without affecting their structure. The surface modification induced a hydrophilic-to-hydrophobic transition, with SPR-based nonwovens showing higher contact angles (>130°), lower water uptake and slower liquid penetration. The applied functionalization strategies suppressed liquid strike-through (STT) across both nonwovens’ formulations. Mechanical performance was also enhanced. SPR-based nonwovens modified with the combined agents showed increases of 59% and 90% to 30/70% SPR/BEKP and 70/30% SPR/BEKP, respectively, while CFS-based nonwovens exhibited increases of 148% and 207% for the same formulations. Wet strength was noticeably improved, exceeding instrumental limits in SPR systems functionalized with polyurethane dispersion alone as well as with the combined agents. Therefore, this functionalization strategy effectively overcomes the intrinsic hydrophilicity and wet weakness of cellulosic nonwovens, enabling to be applied in packaging, household and other technical applications, while promoting the circular economy.

Footwear is traditionally manufactured using non-biodegradable polymers and leather, raising well-documented environmental and health concerns related to their production and disposal. This study explores polyhydroxyalkanoates (PHAs) as sustainable alternatives for bio-based footwear components. A stable aqueous suspension of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) was successfully formulated and applied to cotton fabrics via knife-coating. Various formulations, with and without additives and employing natural or synthetic thickeners, were evaluated in terms of surface morphology, wettability, permeability, and durability. The 10% PHBHHx formulation provided the best balance between material efficiency, coating uniformity, and surface performance. Additives and thermal treatment both influenced wettability, reducing contact angles and enhancing water vapor permeability. Notably, coatings with additives and hot pressing exhibited the highest permeability (68.0 ± 3.1 L/m²/s; 651.0 ± 5.4 g/m²/24 h), while additive-free, non-pressed coatings showed significantly lower values (19.5 ± 4.4 L/m²/s; 245.6 ± 66.2 g/m²/24 h), likely due to excessive compaction. Abrasion resistance remained excellent across all samples, especially with thermal treatment, withstanding 51,200 cycles. Washing resistance results revealed a synergistic effect between additives and heat, promoting long-term hydrophobicity and coating adhesion. Overall, PHBHHx coatings demonstrated potential to enhance water resistance while maintaining breathability, representing a sustainable and effective solution for functional and technical footwear applications.