# Melt-Spun P(3HB)/P(3HB-co-4HB) Monofilaments: Cyclic Loading Behavior and Fabrication into Textile Structures

## TL;DR

Researchers made sustainable textiles from melt-spun P(3HB)/P(3HB-co-4HB) monofilaments, which showed good mechanical resilience and thermal stability.

## Contribution

The study demonstrates the feasibility of processing P(3HB)/P(3HB-co-4HB) monofilaments into textiles with mechanical resilience and thermal robustness.

## Key findings

- Melt-spun P(3HB)/P(3HB-co-4HB) monofilaments have tensile strength of ~138 MPa and elongation at break of ~55%.
- Cyclic loading showed hysteresis that diminishes after the first cycle and can be reset with a 120 s relaxation.
- Adding beta tricalcium phosphate (β-TCP) improved thermal stability but reduced tensile strength.

## Abstract

Melt-spun polyhydroxyalkanoate
monofilaments were successfully
processed into woven and knitted textiles using industrial machinery,
demonstrating their feasibility for textile applications. The filaments,
composed of P­(3HB)/P­(3HB-co-4HB), exhibited an average
tensile strength of ∼138 MPa and an elongation at break of
∼55%, with crystallinity of ∼30%. Cyclic loading of
the filaments revealed pronounced hysteresis during the first cycle,
which diminished in subsequent cycles. However, a relaxation time
of 120 s was sufficient to reset the molecular conformational changes
that occurred during the previous cycles. Furthermore, the incorporation
of beta tricalcium phosphate (β-TCP) particles during melt spinning
reduced tensile strength but improved thermal stability, enhancing
processability. These findings highlight the potential of P­(3HB)/P­(3HB-co-4HB) monofilaments for sustainable textile applications
requiring mechanical resilience and thermal robustness.