Soil Degradation of Polylactic Acid/Polyhydroxyalkanoate-Based Nonwoven Mulches
Soil Degradation of Polylactic Acid/Polyhydroxyalkanoate-Based Nonwoven Mulches
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DOI：
10.1007/s10924-015-0716-9
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发表时间：
2015-09-01
影响因子：
5.3
通讯作者：
Wszelaki, Annette L.
中科院分区：
文献类型：
--
作者：
Dharmalingam, Sathiskumar;Hayes, Douglas G.;Wszelaki, Annette L.
使用非织造纺织技术，将由聚乳酸 (PLA) 以及 PLA 和聚 3-羟基丁酸酯-co-4-羟基丁酸酯（聚羟基烷酸酯，或 PHA）的混合物制备的全生物基农用覆盖物的土壤降解情况与商用可生物降解地膜 BioTelo（Dubois Agrinovation，沃特福德，加拿大）的土壤降解情况进行比较。将 PHA 添加到 PLA 原料混合物中，生产出的非织造布具有较低的拉伸强度和分子量，并增加了覆盖物的平均纤维直径。由 PLA-PHA 72/28 w/w 混合物制备的熔喷 (MB) 非织造覆盖物经历了最大程度的降解，在土壤掩埋 10 周和 30 周期间，拉伸强度分别损失了 78%，重均分子量分别下降了 25.9%。 PHA 的质量分数在土壤埋藏过程中下降，表明 PHA 比 PLA 更容易被微生物同化。 BioTelo 的拉伸强度损失了 29%，但其氯仿可溶成分的分子量没有明显变化。相比之下，纺粘 (SB) PLA 覆盖物在 30 周的土壤埋藏研究中没有发生任何明显的降解。结果表明，MB-PLA + PHA 非织造布可作为一种具有潜在价值的可生物降解农业覆盖物，而 SB-PLA 可用作长期农业应用的可堆肥材料，例如行覆盖物和景观织物。 MB-PLA + PHA 的土壤降解研究直接比较了未经处理的富含堆肥的土壤与灭菌的土壤堆肥混合物，结果表明拉伸强度的损失仅发生在未灭菌的土壤中，表明该事件与土壤微生物直接相关。
The soil degradation of fully biobased agricultural mulches prepared from polylactic acid (PLA) and blends of PLA and poly3-hydroxybutyrate-co-4-hydroxybutyrate (polyhydroxyalkanoate, or PHA) using nonwoven textile technology was compared to that of a commercial biodegradable mulch film, BioTelo (Dubois Agrinovation, Waterford, Canada). The addition of PHA to PLA to the feedstock blend produced nonwovens that possessed lower tensile strength and molecular weight and increased the average fiber diameter of mulches. A meltblown (MB) nonwoven mulch prepared from a PLA-PHA 72/28 w/w blend underwent the greatest degradation, achieving a 78 % loss of tensile strength and a 25.9 % decrease of weight-averaged molecular weight during 10 and 30 week of soil burial, respectively. The mass fraction of PHA decreased during soil burial, suggesting the preferential microbial assimilation of PHA over PLA. BioTelo underwent a 29 % loss of tensile strength but no appreciable change of molecular weight for its chloroform-soluble components. In contrast, spunbond (SB) PLA mulches did not undergo any appreciable degradation during the 30 week soil burial studies. The results suggest that the MB-PLA + PHA nonwoven may serve as a potentially valuable biodegradable agricultural mulch, and that SB-PLA may be useful as a compostable material for long-term agricultural applications, such as row covers and landscape fabrics. A soil degradation study of MB-PLA + PHA that directly compared untreated compost-enriched soil to sterilized soil-compost mixture demonstrated that the loss of tensile strength occurred only in the unsterilized soil, suggesting this event is directly associated with soil microorganisms.