The excessive use of plastics, in addition to the limitative capacities available for plastic waste disposal or recycle increased the interest in degradable polymers. Polylactic acid (PLA) and polyhydroxybutyrate (PHB) are among the most studied biobased polymers for packaging applications. However, their biodegradability in real environment is questionable. Therefore, the purpose of this study was to investigate the biodegradation behavior of PLA/PHB blend films and their sandwich-structured composites containing a cellulose paper interlayer, in natural soil environment, exposed to humidity and temperature conditions specific to different seasons. The study was conducted for 8 months and the biodegradation process was evaluated by measuring the morphological changes, weight loss and tensile properties of the samples. The weight loss data showed that materials were able to degrade under the action of soil microorganisms, water and heat. Moreover, the cellulose layer favored the water retention and enhanced the degradation. SEM images highlighted traces of erosion and biodegradation in the case of the buried samples and FTIR spectra revealed the scission of the ester bonds, which proved the degradation of the aliphatic polyesters. The XRD studies showed that the samples recovered from compost soil were more crystalline than those stored at room temperature, which indicates the degradation of the amorphous phase in the samples. In addition, DMA measurements showed a strong reinforcing effect of the cellulose interlayer on the PLA/PHB matrix. In conclusion, PLA/PHB blend is suitable for long packaging application, but the addition of a cellulose paper interlayer is beneficial to accelerate the decomposition rate.

除了可用于处理塑料废物或回收的限制能力之外，过量使用塑料增加了人们对可降解聚合物的兴趣。聚乳酸（PLA）和聚羟基丁酸酯（PHB）是用于包装应用的研究最多的生物基聚合物。但是，它们在实际环境中的生物降解性值得怀疑。因此，本研究的目的是研究PLA / PHB共混膜及其包含纤维素纸中间层的三明治结构复合材料在自然土壤环境中暴露于不同季节的湿度和温度条件下的生物降解行为。该研究进行了8个月，并通过测量样品的形态变化，重量损失和拉伸性能来评估生物降解过程。失重数据表明材料能够在土壤微生物，水和热的作用下降解。此外，纤维素层有利于保水并促进降解。SEM图像突出显示了被埋样品的腐蚀和生物降解痕迹，FTIR光谱揭示了酯键的断裂，证明了脂肪族聚酯的降解。XRD研究表明，从堆肥土壤中回收的样品比室温下保存的样品具有更高的结晶度，这表明样品中非晶相的降解。此外，DMA测量显示纤维素夹层对PLA / PHB基质具有很强的增强作用。总之，PLA / PHB混合物适用于长包装应用，