Centro Tecnológico, de Ciências Exatas e Educação (CTE), Universidade Federal de Santa Catarina, Rua João Pessoa, 2514, Blumenau, 89036-004, SC, Brazil.
Área do Conhecimento de Ciências Exatas e Engenharias, Universidade de Caxias do Sul, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, RS, Brazil.
Int J Biol Macromol. 2024 Oct;277(Pt 1):133768. doi: 10.1016/j.ijbiomac.2024.133768. Epub 2024 Jul 8.
The aim of this work was to evaluate the influence of halloysite clay nanoparticles - unmodified (Hal) and organically modified (mHal) - and oregano essential oil (OEO), used as an antimicrobial agent in active packaging, on the biodegradation behavior of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) films. Five samples were prepared by melt mixing using 3 wt% clay, and 8 wt% and 10.4 wt% OEO. PHBV compositions containing OEO presented the highest rate of biodegradation, achieving 46% of mass loss after aging for 12 weeks in simulated soil. The addition of clay nanoparticles reduced the polymer's biodegradation to 32%. The compositions containing OEO showed a rough and layered surface with visible cracks, indicating degradation occurring through layer-by-layer erosion from the surface. This degradation was confirmed by the chemical changes on the surface of all samples, with a slight decrease in molar masses. The composition containing 8 wt% OEO presented an increase in the crystallization degree as a result of the preferential consumption of amorphous phase, whereas for the compositions containing clay nanoparticles, both crystalline and amorphous regions were degraded at similar rates. Therefore, the combination of additives allows the biodegradation process of PHBV to be controlled for use in the production of active packaging.
本工作旨在评估海泡石纳米粘土 - 未改性（Hal）和有机改性（mHal） - 以及牛至精油（OEO）的影响，牛至精油作为抗菌剂用于活性包装，对聚（羟基丁酸酯-共-羟基戊酸酯）（PHBV）薄膜的生物降解行为的影响。使用 3wt%粘土和 8wt%和 10.4wt% OEO 通过熔融混合制备了 5 种样品。含有 OEO 的 PHBV 组合物具有最高的生物降解率，在模拟土壤中老化 12 周后达到 46%的质量损失。粘土纳米颗粒的添加将聚合物的生物降解率降低至 32%。含有 OEO 的组合物表面粗糙且呈层状，有明显的裂缝，表明降解是通过从表面逐层侵蚀发生的。所有样品表面的化学变化都证实了这种降解，摩尔质量略有下降。由于非晶相的优先消耗，含有 8wt% OEO 的组合物表现出结晶度的增加，而对于含有粘土纳米颗粒的组合物，结晶区和非晶区以相似的速率降解。因此，添加剂的组合可以控制 PHBV 的生物降解过程，用于生产活性包装。
