To enhance the degradability of poly(butylene adipate-co-terephthalate) (PBAT), reed fiber (RF) was blended with PBAT to create composite materials. In this study, a fifteen day degradation experiment was conducted using four different enzyme solutions containing lipase, cellulase, Proteinase K, and esterase, respectively. The degradation process of the sample films was analyzed using an analytical balance, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The PBAT/RF composites exhibited an increased surface hydrophilicity, which enhanced their degradation capacity. Among all the enzymes tested, lipase had the most significant impact on the degradation rate. The weight loss of PBAT and PBAT/RF, caused by lipase, was approximately 5.63% and 8.17%, respectively. DSC analysis revealed an increase in the melting temperature and crystallinity over time, especially in the film containing reed fibers. FTIR results indicated a significant weakening of the ester bond peak in the samples. Moreover, this article describes a biodegradation study conducted for three months under controlled composting conditions of PBAT and PBAT/RF samples. The results showed that PBAT/RF degraded more easily in compost as compared to PBAT. The lag phase of PBAT/RF was observed to decrease by 23.8%, while the biodegradation rate exhibited an increase of 11.8% over a period of 91 days. SEM analysis demonstrated the formation of more cracks and pores on the surface of PBAT/RF composites during the degradation process. This leads to an increased contact area between the composites and microorganisms, thereby accelerating the degradation of PBAT/RF. This research is significant for preparing highly degradable PBAT composites and improving the application prospects of biodegradable green materials. PBAT/RF composites are devoted to replacing petroleum-based polymer materials with sustainable, natural materials in advanced applications such as constructional design, biomedical application, and eco-environmental packaging.

Poly (butylene adipate-co-terephthalate) (PBAT) and PBAT/reed fiber (RF) mulch films were prepared. The molecular structural changes and surface morphological evolution during the degradation process were systematically characterized using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The prepared PBAT/RF mulch film biodegradation rate reached 90.43% within 91 days under controlled composting conditions, which was 9.52% higher than a pure PBAT mulch film. The effects of adding PBAT and PBAT/RF microplastics on soil properties and soybean physiological indicators were dynamic. The study demonstrated that the incorporation of 5% PBAT/RF mulch film fragments into soil led to a 5.1% reduction in soil pH and a 17.2% increase in soluble organic carbon content. While the effects of 5% PBAT/RF on soil urease and neutral phosphatase activities were non-significant, sucrase activity decreased by 7.4% and catalase activity was reduced to 0.38 U/g. Additionally, the addition of 5% PBAT/RF resulted in a soybean germination rate of 93.74%, which was 4.0% higher than that observed in the group treated with 5% PBAT alone. The experimental data revealed a 7.2% reduction in leaf chlorophyll content, with concomitant growth inhibition in the soybean seedlings. The study demonstrated that the PBAT/RF composite film achieved 89% biodegradation within 180 days under field conditions, effectively mitigating post-application effects on agroecosystems compared to conventional polyethylene mulch.