Poly(lactic acid) (PLA) films with 1 wt% of amber extract (AbE) as a bio-additive were obtained through solvent mixing using 1,4-dioxane, which was later evaporated. The extract, derived from the residual amber generated during jewelry manufacturing in the Gdansk region (Poland), was evaluated for its morphology and thermal response. The resulting films were transparent, and the addition of AbE imparted a yellow hue. The crystallinity characteristics of the PLA/AbE films were analyzed through FTIR, DSC, POM, and XRD results. The cold crystallization ability of PLA in the presence of AbE was assessed by comparing the films with their annealed counterparts. The annealed films demonstrated a slight increase in the crystalline phase without any change in transparency. The presence of amber extract particles impeded the formation of stable polymorph crystals within the PLA structure, leading to an expanded size distribution of spherulites and a reduced crystallization rate. Furthermore, the addition of AbE showed promise in enhancing the UV–vis blocking of PLA, as AbE particles decreased the transmission rate across the entire UV–vis spectrum.

中文翻译：

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琥珀提取物作为聚乳酸薄膜的生物添加剂：结晶度和稳定性的多方法分析

通过使用 1,4-二恶烷进行溶剂混合，然后蒸发，获得含有 1 wt% 琥珀提取物 (AbE) 作为生物添加剂的聚乳酸 (PLA) 薄膜。该提取物取自格但斯克地区（波兰）珠宝制造过程中产生的残留琥珀，对其形态和热响应进行了评估。所得薄膜是透明的，并且 AbE 的添加赋予了黄色色调。通过 FTIR、DSC、POM 和 XRD 结果分析了 PLA/AbE 薄膜的结晶度特征。通过将薄膜与其退火对应物进行比较，评估了在 AbE 存在下 PLA 的冷结晶能力。退火后的薄膜显示出结晶相略有增加，但透明度没有任何变化。琥珀提取物颗粒的存在阻碍了 PLA 结构内稳定多晶型晶体的形成，导致球晶尺寸分布扩大和结晶速率降低。此外，AbE 的添加有望增强 PLA 的紫外-可见光阻挡能力，因为 AbE 颗粒降低了整个紫外-可见光谱的透射率。