Moreno-Bohorquez Elizabeth, Arias-Tapia Mary Judith, Martínez-Villadiego Keydis, Rhenals-Julio Jesús D, Jaramillo Andrés F
Chemical Engineering Program, School of Engineering, Universidad Tecnológica de Bolívar, Parque Industrial y Tecnológico Carlos Vélez Pombo km 1 Vía Turbaco, Cartagena 130010, Colombia.
Departamento de Ingeniería Mecánica, Universidad de Córdoba, Cr 6 #76-103, Montería 230002, Colombia.
Polymers (Basel). 2025 May 8;17(10):1295. doi: 10.3390/polym17101295.
In this study, the aerobic degradation of sweet potato (; ) and diamond yam (; ) thermoplastic starch (TPS) blends, combined with polylactic acid (PLA) and varying ratios of citric acid (CA) as a crosslinker, was investigated in compost and seawater environments. After 50 d of composting, weight losses in the SP-TPS/CA/PLA blends were 56.9%, 52.3%, and 77.5%, while those of DY-TPS/CA/PLA were 55.8%, 52.2%, and 62.2% for 0%, 1%, and 5% CA, respectively. In seawater, the SP-TPS/CA/PLA blends showed weight losses of 52.9%, 46.8%, and 61.5%, and the DY-TPS/CA/PLA blends lost 35.2%, 32.1%, and 43.9% for the same CA ratios, respectively. In both media, SEM revealed structural damage, holes, cracks, and changes in coloration, reflecting microbial activity. Additionally, in compost and seawater, TGA results showed that PLA remained the predominant component after 50 d, as most of the degradation occurred on TPS due to its amorphous structure and higher hydrophilicity. In both media, the SP-TPS/CA5/PLA and DY-TPS/CA5/PLA blends exhibited faster degradation, whereas SP-TPS/CA1/PLA and DY-TPS/CA1/PLA displayed higher stability and lower disintegration. Additionally, all blends required over 50 d to degrade completely, as evidenced by the absence of a plateau phase in the biodegradability curves. Statistical analysis showed that, in seawater, the degradation behavior of the blends was similar to cellulose. However, the CA ratio had a greater impact on the compost degradation of the blends with SP-TPS than on DY-TPS. Therefore, the critical factors influencing the degradation of these blends are the starch source and the CA ratio.
在本研究中，对红薯（；）和紫薯（；）热塑性淀粉（TPS）共混物与聚乳酸（PLA）以及不同比例柠檬酸（CA）作为交联剂的有氧降解情况，在堆肥和海水环境中进行了研究。堆肥50天后，对于0%、1%和5%的CA，SP-TPS/CA/PLA共混物的失重分别为56.9%、52.3%和77.5%，而DY-TPS/CA/PLA的失重分别为55.8%、52.2%和62.2%。在海水中，对于相同的CA比例，SP-TPS/CA/PLA共混物的失重分别为52.9%、46.8%和61.5%，DY-TPS/CA/PLA共混物的失重分别为35.2%、32.1%和43.9%。在两种介质中，扫描电子显微镜（SEM）显示结构破坏、孔洞、裂缝以及颜色变化，反映了微生物活性。此外，在堆肥和海水中，热重分析（TGA）结果表明，50天后PLA仍然是主要成分，因为由于TPS的无定形结构和较高的亲水性，大部分降解发生在TPS上。在两种介质中，SP-TPS/CA5/PLA和DY-TPS/CA5/PLA共混物表现出更快的降解，而SP-TPS/CA1/PLA和DY-TPS/CA1/PLA显示出更高的稳定性和更低的崩解性。此外，所有共混物完全降解都需要超过50天，这在生物降解曲线中没有平稳期得到了证明。统计分析表明，在海水中，共混物的降解行为与纤维素相似。然而，CA比例对含SP-TPS共混物在堆肥中的降解影响比对DY-TPS的影响更大。因此，影响这些共混物降解的关键因素是淀粉来源和CA比例。
