Department of Chemical Engineering, Indian Institute of Technology, Guwahati, Assam, India.
Department of Civil Engineering, Indian Institute of Technology, Guwahati, Assam, India.
J Environ Manage. 2020 May 1;261:110211. doi: 10.1016/j.jenvman.2020.110211. Epub 2020 Mar 2.
The current study evaluates aerobic biodegradation of melt extruded poly(lactic acid) PLA based blends under composting conditions. Samples of neat PLA (NPLA) and bio-based polyblend composites of PLA/LLDPE (linear low-density polyethylene) having different concentration of MCC (microcrystalline cellulose crystal) were analyzed to understand the biodegradation behavior of these blends under simulated composting conditions. Biodegradation kinetics revealed that higher content of MCC and PLA accelerated the biodegradation process of the polymeric blends. Increase in the spherulite growth size and decrease in the spherulite density of the biodegraded samples confirmed the decline in amorphous portion of the test samples due to microbial assimilation, leaving behind the crystalline portion. Surface morphological analysis revealed that the samples of PLA/LLDPE/MCC blends underwent surface erosion prior to bulk biodegradation (50-80%) until the 90th day and the PLA formed fibril-like structures after degradation. This study would help in the design and preparation of biodegradable bio-based commercial blends in the future.
本研究评估了在堆肥条件下熔融挤出聚乳酸（PLA）基共混物的需氧生物降解性能。对纯 PLA（NPLA）和不同 MCC（微晶纤维素晶体）浓度的 PLA/LLDPE（线性低密度聚乙烯）生物基共混复合材料进行了分析，以了解这些共混物在模拟堆肥条件下的生物降解行为。生物降解动力学表明，较高含量的 MCC 和 PLA 加速了聚合物共混物的生物降解过程。生物降解样品中球晶生长尺寸的增加和球晶密度的降低证实了由于微生物同化，测试样品的无定形部分减少，留下结晶部分。表面形貌分析表明，在 90 天之前，PLA/LLDPE/MCC 共混物的样品在进行体相生物降解（50-80%）之前经历了表面侵蚀，降解后 PLA 形成了纤维状结构。这项研究将有助于未来设计和制备可生物降解的生物基商业共混物。
