The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was prepared via a melt transesterification route. The resultant bioactive oligomer was then mixed with a blend of polylactide (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with different loadings to manufacture films to be used as a bioactive, biodegradable mulch to deliver the herbicide to target broadleaf weed species. The biological targeting of the MCPA-PHBV conjugate in the mulch film was investigated under glasshouse conditions using faba bean (Vicia faba) as a selective (nontarget) model crop species having broadleaf morphology. The presence of the MCPA-PHBV conjugate in the biodegradable PBTA/PLA blend was shown to completely suppress the growth of broadleaf weed species while displaying only a mild effect on the growth of the model crop. The degradation of the mulch film under glasshouse conditions was quite slow. The release of the MCPA-PHBV during this process was detected using NMR, GPC, EDS, and DSC analyses, indicating that the majority of the MCPA diffused out after MCPA-PHBV conjugate bond scission. These data provide a strong “proof of concept” and show that this biodegradable, bioactive film is a good candidate for future field applications and may be of wide agricultural applicability.

中文翻译：

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具有生物活性MCPA-PHBV的可生物降解的PBAT / PLA共混物可抑制杂草生长

与聚（3-羟基丁酸酯共轭除草剂2-甲基-4-氯苯氧乙酸（MCPA）共-3-羟基戊酸酯）（PHBV），制备通过熔融酯交换路线。将所得的生物活性的低聚物，然后用聚乳酸（PLA）的共混物混合，并且聚（亚丁基己二酸酯共-terephthalate）（PBAT）具有不同的载荷来制造膜被用作生物活性，可生物降解地膜递送除草剂目标阔叶杂草种类。使用蚕豆（蚕豆）在温室条件下研究了覆盖膜中MCPA-PHBV共轭物的生物靶向性）作为具有阔叶形态的选择性（非目标）模型作物。在可生物降解的PBTA / PLA共混物中存在MCPA-PHBV共轭物，可以完全抑制阔叶杂草的生长，而对模型作物的生长仅表现出温和的作用。在温室条件下，覆盖膜的降解非常缓慢。使用NMR，GPC，EDS和DSC分析检测到此过程中MCPA-PHBV的释放，表明MCPA-PHBV共轭键断裂后大部分MCPA扩散了。这些数据提供了有力的“概念验证”，并表明这种可生物降解的生物活性薄膜是未来田间应用的良好候选者，可能具有广泛的农业应用性。