Bio-Based PBS for the Textile Industry
Abstract
In recent years, bio-based polymers have received increasing attention. For a true transition to a green economy, polymers should not only come from renewable sources but also be biodegradable. One such polymer is polybutylene succinate (PBS), which is labeled as home compostable—meaning it can break down at lower, less controlled temperatures, such as those found in a typical garden compost heap.
This article explores PBS's potential in textile applications, focusing on tape and multifilament extrusion, coloring, and small-scale fabric processing. Alongside virgin PBS, blends with 25% and 50% PLA were also evaluated.
Introduction
"Biodegradable" refers to materials that can decompose in a relatively short period under specific conditions. These conditions can vary significantly (Figure 1).
For instance, PLA (polylactic acid) requires industrial composting conditions (50–60°C), while some polymers are home compostable at ambient temperatures (<35°C). This characteristic is valuable not only environmentally but also technically—especially in applications like agrotextiles.
PBS is one such polymer. It is produced via the polycondensation of succinic acid and 1,4-butanediol. Succinic acid, traditionally petroleum-derived, can now be obtained from renewable sources, making PBS a partially bio-based polymer with potential to become fully bio-based.
Thanks to its renewable origin, biodegradability, and physical properties comparable to polyolefins, PBS is considered a promising material for the future. While it is already used in the plastics industry (e.g., packaging), its application in textiles is still emerging. The PBSTex project by Centexbel investigated this potential.
Materials
Various grades of PBS were tested in the PBSTex project: FZ 71 PB and FZ 91 PB, both produced by PTTMCC. These are 50% bio-based—the succinic acid component is renewable, while the 1.4-butanediol remains petroleum-based (with future plans for full bio-based production).
PBS melts at 113°C and starts degrading around 300°C.
- FZ 91 PB: Low melt flow index (MFI) of 5 g/10 min (190°C); ideal for monofilament and tape extrusion.
- FZ 71 PB: Higher MFI of 22 g/10 min (190°C); better suited for multifilament extrusion.
Capillary rheology testing of FZ 71 PB shows shear thinning behavior: viscosity decreases as shear rate and temperature increase.
Tape Extrusion
Trials on a semi-industrial tape extrusion line showed that although PBS has a low melting point, high extruder temperatures (>200°C) are necessary for proper processing.
At the optimal cold draw ratio (4.8x):
- Tenacity: 0.22–0.23 N/tex
- Young’s modulus: 1.4–1.5 N/tex
Blending PBS with 25% or 50% PLA (grade 6400D) improved mechanical properties (Table 1). Notably, the Young’s modulus increased significantly from 1.4 to 4.0 N/tex.
Mechanical Properties of Tapes
| Composition | Tenacity (N/tex) | Modulus (N/tex) |
|---|---|---|
| 100% PBS | 0.22–0.23 | 1.4–1.5 |
| 75% PBS / 25% PLA 50% | 0.24–0.25 | 2.4–2.5 |
| 50% PBS / 50% PLA | 0.28–0.29 | 3.9–4.0 |
Multifilament Extrusion
Trials were also done on a semi-industrial multifilament line. The filaments were air-cooled and then stretched over four heated rollers, with a final relaxation roll. For bulked continuous filaments (BCF), a texturizing chamber transformed the filaments into a bulked form.
- Continuous filament (CF): Extruder temp ~230°C
- BCF (trilobal die): Extruder temp lowered to 210–200°C
Mechanical Properties of Multifilaments
Crimp behavior, which affects the bulkiness and appearance in carpets, was better in PBS compared to PLA—indicating potential for specific performance-based applications when blended.
| Type | Tenacity (N/tex) | Modulus (N/tex) |
|---|---|---|
| 100% PBS CF | 0.16–0.20 | 1.0–1.3 |
| 100% PBS BCF | 0.11–0.12 | 0.6–0.7 |
Colouring PBS Yarns
PBS yarns were colored using two techniques:
- Solution dyeing – A 1% PLA-based masterbatch was added during tape extrusion. PBS tapes showed similar light fastness to PLA in Xeno tests for indoor (ISO 105B02) and outdoor (ISO 105B04) use (Figure 3).
- Package dyeing – Disperse dyes (Dianix range) were applied at 70°C, based on PLA dye recipes. Results (Table 3) showed that PBS yarns dyed at 70°C achieved intense colors, while PLA yarns appeared very pale unless dyed at 110°C. This is likely due to PBS’s lower glass transition temperature (Tg ≈ -30°C), allowing better dye penetration.
Yarn-to-Fabric Processing
As demonstration materials:
- Knitted and nonwoven fabrics were made from multifilaments
- Woven fabric was produced from PBS tapes
Both knitted and woven fabrics showed good abrasion resistance (ISO 12947-2). The knitted fabric also had positive pilling resistance (ISO 12945-2).
Conclusions
PBS demonstrates strong potential for textile applications. It can be processed using standard industrial equipment for tape and multifilament extrusion, enabling integration into products like agrotextile tapes and interior BCF yarns.
PBS properties can be tailored by blending with bio-based polymers like PLA, enhancing specific performance traits.
Additionally, the combination of home compostability and bio-based content offers major environmental benefits—reducing fossil fuel reliance and CO₂ emissions, while enabling efficient end-of-life options aligned with the circular economy.
