Jia Xuehua, Wen Qilin, Sun Yanjun, Chen Yinghong, Gao Dali, Ru Yue, Chen Ning
State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
Sinopec (Beijing) Research Institute of Chemical and Industry Co., Ltd., Beijing 100013, China.
Polymers (Basel). 2024 Oct 20;16(20):2942. doi: 10.3390/polym16202942.
Replacing traditional disposable, non-biodegradable plastic packaging with biodegradable plastic packaging is one of the key approaches to address the issue of "white pollution". PBAT/PLA/inorganic filler composites are widely utilized as a biodegradable material, commonly employed in the field of packaging films. However, the poor dispersion of inorganic fillers in the polymer matrix and the limited compatibility between PBAT and PLA have led to inferior mechanical properties and elevated costs. In this work, we propose a simple and effective strategy to improve the dispersion of nano-CaCO in a PBAT/PLA matrix through solid-state shear- milling (SM) technology, combined with mechanochemical modification and in situ compatibilization to enhance the compatibility between PBAT and PLA. The impact of varying milling conditions on the structure and performance of the PBAT/PLA/CaCO composites was investigated. During the milling process, PBAT and PLA undergo partial molecular chain fragmentation, generating more active functional groups. In the presence of the chain extender ADR during melt blending, more branched PBAT-g-PLA is formed, thereby enhancing matrix compatibility. The results indicate that the choice of milling materials significantly affects the structure and properties of the composite. The film obtained by milling only PBAT and CaCO exhibited the best performance, with its longitudinal tensile strength and fracture elongation reaching 22 MPa and 437%, respectively. This film holds great potential for application in the field of green packaging.
用可生物降解塑料包装取代传统的一次性、不可生物降解塑料包装是解决“白色污染”问题的关键途径之一。PBAT/PLA/无机填料复合材料作为一种可生物降解材料被广泛应用，常用于包装薄膜领域。然而，无机填料在聚合物基体中分散性差以及PBAT与PLA之间的相容性有限，导致其机械性能较差且成本较高。在这项工作中，我们提出了一种简单有效的策略，通过固态剪切磨（SM）技术改善纳米CaCO₃在PBAT/PLA基体中的分散性，结合机械化学改性和原位增容来增强PBAT与PLA之间的相容性。研究了不同研磨条件对PBAT/PLA/CaCO₃复合材料结构和性能的影响。在研磨过程中，PBAT和PLA发生部分分子链断裂，产生更多活性官能团。在熔融共混过程中加入扩链剂ADR时，会形成更多支化的PBAT-g-PLA，从而增强基体相容性。结果表明，研磨材料的选择对复合材料的结构和性能有显著影响。仅研磨PBAT和CaCO₃得到的薄膜性能最佳，其纵向拉伸强度和断裂伸长率分别达到22 MPa和437%。该薄膜在绿色包装领域具有巨大的应用潜力。
