Periodic Reporting for period 1 - PolyBioDeg (Structure-properties of melt-spun bioplastic fibers in correlation with their biodegradation behaviour and mechanical performance)
Période du rapport: 2023-05-01 au 2025-04-30
The PolyBioDeg project addresses the urgent need for sustainable alternatives to conventional synthetic textile fibers, which are a major source of microplastic pollution and long-term environmental harm. With more than 60% of global textiles made from non-biodegradable fossil-based polymers like PET and PA, the textile industry urgently requires a shift toward circular, bio-based solutions with no persistent microplastics. PolyBioDeg aims to investigate the correlation of structure-properties of melt-spun biodegradable fibers making fibers from different biodegradable polymers and testing in different conditions (including biodegradation).
The project builds upon promising lab-scale results already achieved by Senbis Polymer Innovations, where PLA-based filaments were successfully melt-spun and drawn to create continuous yarns. These early findings serve as proof of technical feasibility and open the pathway for further optimization of mechanical properties and process stability. The project's strategic objective is to understand the requirements for a biodegradable textile fiber while considering the mechanical properties and sustainability in correlation with the chemistry of the polymer, processing parameters, and environmental conditions.
PolyBioDeg aligns with European Green Deal goals and the EU Strategy for Sustainable and Circular Textiles by directly tackling plastic pollution at its source. It will deliver a significant impact by fundamental understanding about the correlation between chemistry-processing-properties-biodegradation while enabling the replacement of conventional synthetic fibers in selected product categories, thereby reducing the environmental footprint and supporting the transition to a bio-based economy. The consortium’s multidisciplinary approach ensures a holistic development trajectory from formulation to application, setting the stage for future market entry and regulatory readiness.
The project builds upon promising lab-scale results already achieved by Senbis Polymer Innovations, where PLA-based filaments were successfully melt-spun and drawn to create continuous yarns. These early findings serve as proof of technical feasibility and open the pathway for further optimization of mechanical properties and process stability. The project's strategic objective is to understand the requirements for a biodegradable textile fiber while considering the mechanical properties and sustainability in correlation with the chemistry of the polymer, processing parameters, and environmental conditions.
PolyBioDeg aligns with European Green Deal goals and the EU Strategy for Sustainable and Circular Textiles by directly tackling plastic pollution at its source. It will deliver a significant impact by fundamental understanding about the correlation between chemistry-processing-properties-biodegradation while enabling the replacement of conventional synthetic fibers in selected product categories, thereby reducing the environmental footprint and supporting the transition to a bio-based economy. The consortium’s multidisciplinary approach ensures a holistic development trajectory from formulation to application, setting the stage for future market entry and regulatory readiness.
A comprehensive selection of biodegradable polymers was sourced from the market, including polylactic acid (PLA), polyhydroxyalkanoates (PHA), polycaprolactone (PCL), polybutylene succinate (PBS), etc. along with a variety of biodegradable copolymers such as PBAT, PBSA, PBEAS, and so on. These polymers were systematically evaluated for their spinnability, mechanical performance, and biodegradability in the context of multifilament yarn production.
Melt-spinning trials were conducted on a dedicated pilot-scale multifilament line, using precisely controlled process parameters tailored for each polymer type/sample. These trials successfully resulted in the production of uniform multifilament yarns wound on spools, demonstrating process feasibility for several formulations. Parameters such as throughput rate, spinneret design, take-up speed, and drawing ratios were optimized to achieve stable yarn formation and acceptable tenacity.
Thermal characterization was performed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to assess polymer crystallinity, thermal stability, and processing windows. Mechanical testing of the yarns included tensile strength and elongation measurements, providing insights into the structural integrity and application potential of the spun fibers.
In parallel, the biodegradation behavior of the selected polymers was assessed in powder and fiber form under simulated environmental conditions. Tests were performed in soil and wastewater matrices, following standard protocols. Additionally, the disintegration of melt-spun yarns was evaluated via mesocosm experiments, where knitted fabrics made from the experimental yarns were exposed to controlled natural environments. These tests allowed for real-time observation of disintegration kinetics and material integrity loss, providing valuable data for end-of-life behavior in realistic scenarios.
Collectively, these technical activities confirmed the suitability of several biodegradable polymer systems for multifilament spinning and provided a foundational dataset for further formulation and process refinement. The outcomes contribute directly to advancing the project's objective of enabling biodegradable alternatives to conventional synthetic yarns, while giving a good understanding about the effect of chemical backbone of the polymers, processing parameters in fiber level, and the environmental conditions in this ambission.
Melt-spinning trials were conducted on a dedicated pilot-scale multifilament line, using precisely controlled process parameters tailored for each polymer type/sample. These trials successfully resulted in the production of uniform multifilament yarns wound on spools, demonstrating process feasibility for several formulations. Parameters such as throughput rate, spinneret design, take-up speed, and drawing ratios were optimized to achieve stable yarn formation and acceptable tenacity.
Thermal characterization was performed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to assess polymer crystallinity, thermal stability, and processing windows. Mechanical testing of the yarns included tensile strength and elongation measurements, providing insights into the structural integrity and application potential of the spun fibers.
In parallel, the biodegradation behavior of the selected polymers was assessed in powder and fiber form under simulated environmental conditions. Tests were performed in soil and wastewater matrices, following standard protocols. Additionally, the disintegration of melt-spun yarns was evaluated via mesocosm experiments, where knitted fabrics made from the experimental yarns were exposed to controlled natural environments. These tests allowed for real-time observation of disintegration kinetics and material integrity loss, providing valuable data for end-of-life behavior in realistic scenarios.
Collectively, these technical activities confirmed the suitability of several biodegradable polymer systems for multifilament spinning and provided a foundational dataset for further formulation and process refinement. The outcomes contribute directly to advancing the project's objective of enabling biodegradable alternatives to conventional synthetic yarns, while giving a good understanding about the effect of chemical backbone of the polymers, processing parameters in fiber level, and the environmental conditions in this ambission.
This project achieved significant progress in the development and validation of biodegradable multifilament yarns through extensive melt-spinning, material characterization, and environmental degradation testing. The results provide strong evidence for the technical feasibility and environmental relevance of replacing fossil-based synthetic fibers with biodegradable alternatives in textile applications.
A diverse portfolio of biodegradable polymers was selected for evaluation, including PLAs, PHAs, PBS, PGA, and PCL, along with copolymers such as PBAT, PBSA, PBST, PBEAS, PBSeT, and PLGA etc. These materials were subjected to rigorous screening to assess their processability, mechanical properties, and degradation behavior.
Melt-Spinning and Yarn Production:
Pilot-scale melt-spinning trials were conducted to produce continuous multifilament yarns from the selected polymers. Processing parameters—such as temperature, take-up speed, draw ratio, throughput etc. were optimized for each material to ensure stable filament formation. PLA, PBS, and PGA demonstrated particularly good spinnability, resulting in uniform yarns with acceptable tenacity and elongation. The yarns were collected on spools and prepared for further textile processing and testing. PHAs, and some copolymers e.g. PBSA, PBST, and PBAT faced challenges in the spinning process (mostly due to slow crystallization or low melt strength).
Mechanical and Thermal Characterization:
The produced yarns were tested for tensile strength, elongation at break, and Young’s modulus. While PLA and PGA-based yarns showed higher tensile strength, while PCL, PBS, and copolymer yarns were lower in tenacity and higher in elongation. Thermal analysis using DSC and TGA revealed insights into melting behavior, crystallinity, and thermal degradation profiles, critical for defining processing windows and end-use stability.
Abiotic Hydrolysis:
To evaluate polymer stability under abiotic conditions, hydrolysis experiments were conducted at controlled conditions using an NMR-assisted monomer identification method. Hydrolytic degradation, particularly of ester bonds, was significant in polymers such as PLA, PLGA, and PGA, which are known to undergo bulk erosion. On the other hand, the fast biodegradation of some polymers such as PHAs and cellulose is showing that they follow enzymatic hydrolysis pathway.
Biodegradation in Soil and Wastewater:
The biodegradation potential of the polymers was assessed under simulated environmental conditions, specifically in soil and wastewater environments. Testing followed standard protocols (e.g. ISO 17556, ISO 14851) and focused on CO2 evolution (soil) and BOD (wastewater), and physical disintegration (mesocosm). The results showed that PHAs have a high biodegradation rate (even faster than cellulose in some cases) although their abiotic hydrolysis rate is not significant (even slower than PLA). Afterward, some copolymers (especially non-aromatic and less crystalline) e.g. PBSA, PBEAS, PLGA, etc. had faster degradation. The next orders were for PCL and then PBS. The aromatic containing polymers such as PBSeT, and mostly PBAT were before PLA as the last one. Another result was achieved by testing different fibers, showing that the more orientation and crystallization in the fiber or yarn level, the slower the biodegradation rate. This was confirmed by testing fully drawn yarns (FDY) and partially oriented yarns(POY) of PGA and PBS versus each other and the polymer powder. The outcome was clear that polymer powders degraded faster than the POY and then FDY sample.
Key Insights and Conclusions:
The results demonstrate that biodegradable polymers can be effectively processed into multifilament yarns and used in textile applications while also offering measurable environmental benefits at their end-of-life. Material selection plays a critical role in balancing mechanical performance with biodegradability. PLA and PBS emerged as lead candidates due to their favorable spinning behavior and degradation profiles. The study also highlights the need for application-specific matching of polymer properties, as degradation kinetics vary with environmental conditions. Also addressing the durability in the textile application (considering the contradiction with the biodegradation and performance drop) is a key for prospect works.
Overall, the project’s outcomes contribute valuable technical data to guide material selection, regulatory frameworks, and industrial adoption of biodegradable yarns, supporting the broader transition to sustainable textiles.
A diverse portfolio of biodegradable polymers was selected for evaluation, including PLAs, PHAs, PBS, PGA, and PCL, along with copolymers such as PBAT, PBSA, PBST, PBEAS, PBSeT, and PLGA etc. These materials were subjected to rigorous screening to assess their processability, mechanical properties, and degradation behavior.
Melt-Spinning and Yarn Production:
Pilot-scale melt-spinning trials were conducted to produce continuous multifilament yarns from the selected polymers. Processing parameters—such as temperature, take-up speed, draw ratio, throughput etc. were optimized for each material to ensure stable filament formation. PLA, PBS, and PGA demonstrated particularly good spinnability, resulting in uniform yarns with acceptable tenacity and elongation. The yarns were collected on spools and prepared for further textile processing and testing. PHAs, and some copolymers e.g. PBSA, PBST, and PBAT faced challenges in the spinning process (mostly due to slow crystallization or low melt strength).
Mechanical and Thermal Characterization:
The produced yarns were tested for tensile strength, elongation at break, and Young’s modulus. While PLA and PGA-based yarns showed higher tensile strength, while PCL, PBS, and copolymer yarns were lower in tenacity and higher in elongation. Thermal analysis using DSC and TGA revealed insights into melting behavior, crystallinity, and thermal degradation profiles, critical for defining processing windows and end-use stability.
Abiotic Hydrolysis:
To evaluate polymer stability under abiotic conditions, hydrolysis experiments were conducted at controlled conditions using an NMR-assisted monomer identification method. Hydrolytic degradation, particularly of ester bonds, was significant in polymers such as PLA, PLGA, and PGA, which are known to undergo bulk erosion. On the other hand, the fast biodegradation of some polymers such as PHAs and cellulose is showing that they follow enzymatic hydrolysis pathway.
Biodegradation in Soil and Wastewater:
The biodegradation potential of the polymers was assessed under simulated environmental conditions, specifically in soil and wastewater environments. Testing followed standard protocols (e.g. ISO 17556, ISO 14851) and focused on CO2 evolution (soil) and BOD (wastewater), and physical disintegration (mesocosm). The results showed that PHAs have a high biodegradation rate (even faster than cellulose in some cases) although their abiotic hydrolysis rate is not significant (even slower than PLA). Afterward, some copolymers (especially non-aromatic and less crystalline) e.g. PBSA, PBEAS, PLGA, etc. had faster degradation. The next orders were for PCL and then PBS. The aromatic containing polymers such as PBSeT, and mostly PBAT were before PLA as the last one. Another result was achieved by testing different fibers, showing that the more orientation and crystallization in the fiber or yarn level, the slower the biodegradation rate. This was confirmed by testing fully drawn yarns (FDY) and partially oriented yarns(POY) of PGA and PBS versus each other and the polymer powder. The outcome was clear that polymer powders degraded faster than the POY and then FDY sample.
Key Insights and Conclusions:
The results demonstrate that biodegradable polymers can be effectively processed into multifilament yarns and used in textile applications while also offering measurable environmental benefits at their end-of-life. Material selection plays a critical role in balancing mechanical performance with biodegradability. PLA and PBS emerged as lead candidates due to their favorable spinning behavior and degradation profiles. The study also highlights the need for application-specific matching of polymer properties, as degradation kinetics vary with environmental conditions. Also addressing the durability in the textile application (considering the contradiction with the biodegradation and performance drop) is a key for prospect works.
Overall, the project’s outcomes contribute valuable technical data to guide material selection, regulatory frameworks, and industrial adoption of biodegradable yarns, supporting the broader transition to sustainable textiles.