Borelbach Pia, Kopitzky Rodion, Dahringer Jörg, Gutmann Patrick
Fraunhofer Institut für Umwelt-, Sicherheits- und Energietechnik UMSICHT, 46047 Oberhausen, Germany.
Indorama Ventures Fibers Germany GmbH, 86399 Bobingen, Germany.
Polymers (Basel). 2023 Jul 6;15(13):2959. doi: 10.3390/polym15132959.
In open environment applications, fibers are increasingly being used that are expected to biodegrade in the soil after their desired service life. Biodegradable polymer fibers are a versatile alternative to natural fibers. In this study, the degradation behavior of fibers made from polylactic acid (PLA) and a polyhydroxy alkanoate (PHA) blend with PLA, as well as a bicomponent fiber (BICO) made from polybutylene succinate (PBS) and PLA, was investigated. The fibers were stored in topsoil at 23 °C for 12 weeks. In addition, fibers were stored in compost at 58 °C for 4 weeks to investigate the degradation behavior in an industrial composting plant. Reference materials were also stored without substrate under the same temperatures and humidity conditions. Samples were taken regularly, and mechanical testing, scanning electron microscopy (SEM), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and infrared spectroscopy (IR) were used to study the degradation of the fibers. After 12 weeks in soil at ambient temperatures, the PLA and BICO fibers showed no degradation. The PHA fibers showed cracks in SEM, a decrease in molecular weight, and changes in the IR spectrum. No evidence of biological influence (bacteria or fungi) was found. Under industrial composting conditions, all fibers showed a decrease in strength and molecular weight. For the BICO and the PHA fibers, the SEM images show significant changes. Especially in the PHA fibers, fungal mycelia can be seen. The studies provide a better insight into the processes involved in the degradation behavior under different environmental conditions.
在开放环境应用中，越来越多地使用预期在达到其预期使用寿命后能在土壤中生物降解的纤维。可生物降解的聚合物纤维是天然纤维的一种通用替代品。在本研究中，对由聚乳酸（PLA）和与PLA共混的聚羟基烷酸酯（PHA）制成的纤维，以及由聚丁二酸丁二醇酯（PBS）和PLA制成的双组分纤维（BICO）的降解行为进行了研究。将这些纤维在23℃的表土中储存12周。此外，将纤维在58℃的堆肥中储存4周，以研究在工业堆肥厂中的降解行为。参考材料也在相同温度和湿度条件下无基质储存。定期取样，并使用力学测试、扫描电子显微镜（SEM）、凝胶渗透色谱（GPC）、差示扫描量热法（DSC）和红外光谱（IR）来研究纤维的降解情况。在环境温度下于土壤中放置12周后，PLA和BICO纤维未显示出降解。PHA纤维在SEM中显示出裂纹、分子量降低以及红外光谱发生变化。未发现生物影响（细菌或真菌）的证据。在工业堆肥条件下，所有纤维的强度和分子量均降低。对于BICO和PHA纤维，SEM图像显示出显著变化。特别是在PHA纤维中，可以看到真菌菌丝体。这些研究更好地洞察了不同环境条件下降解行为所涉及的过程。
