Recycling and Reprocessing of Thermoplastic Polyurethane Materials towards Nonwoven Processing

Area of Science:

• Polymer Science
• Materials Science
• Sustainable Materials

Background:

• Thermoplastic Polyurethane (TPU) is a versatile material with tunable properties due to its block-copolymer structure.
• Increasing interest in circular economy and TPU's cost drives the need for effective recycling of production and post-consumer waste.
• Understanding property changes during recycling is crucial for sustainable TPU utilization.

Purpose of the Study:

• To systematically investigate the property alterations of Thermoplastic Polyurethane (TPU) after multiple recycling cycles.
• To characterize the impact of recycling on TPU's molecular characteristics, morphology, and mechanical performance.
• To evaluate the processability and properties of recycled TPU for nonwoven fabric production via melt blowing.

Main Methods:

• Gel permeation chromatography (GPC) to assess molar mass changes.
• Differential scanning calorimetry (DSC) and atomic force microscopy (AFM) to analyze morphological alterations.
• Melt blowing process to produce nonwoven fabrics from recycled TPU, followed by mechanical property evaluation.

Main Results:

• Recycling cycles led to a decrease in molar mass and viscosity, confirmed by GPC and processing load.
• Morphological changes were observed at lower molar masses, characterized by DSC and AFM.
• Molar mass was identified as the primary factor influencing mechanical performance and processing of melt-blown recycled TPU.

Conclusions:

• The study demonstrates that recycling impacts TPU's fundamental properties, primarily molar mass and morphology.
• Recycled TPU can be processed into nonwoven fabrics, with molar mass dictating performance and processability.
• Findings support the sustainable recycling of TPU, providing insights for material design and application development.