State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Adv Mater. 2021 Apr;33(13):e2007371. doi: 10.1002/adma.202007371. Epub 2021 Feb 26.
It is challenging to fabricate degradable poly(vinyl alcohol) (PVA)-based plastics that can be used in watery environments because PVA is soluble in water. In this study, PVA-based supramolecular plastics with excellent degradability in soil and high mechanical strength in watery environments are fabricated by the complexation of vanillin-grafted PVA (VPVA), hydrophobic humic acid (HA), and Fe ions (hereafter denoted as VPVA-HA-Fe complexes). Large-area PVA-based plastics can be easily prepared from a solution of VPVA-HA-Fe complexes using a blade-coating method. The high-density of hydrogen bonds and coordination interactions, as well as the reinforcement of self-assembled Fe -chelated HA nanoparticles, facilitate the fabrication of PVA-based plastics with a breaking strength of ≈85.0 MPa. After immersion in water at room temperature for 7 d, the PVA-based plastics exhibit a breaking strength of ≈26.2 MPa, which is similar to that of polyethylene in its dry state. Furthermore, owing to the reversibility of the hydrogen bonds and coordination interactions, the VPVA-HA-Fe plastics are recyclable and can be conveniently processed into plastic products with desired shapes. After being placed under soil for ≈108 d, the PVA-based plastics are completely degraded into nontoxic species without requiring manual interference.
制备可在水相环境中使用的可降解聚乙烯醇（PVA）基塑料极具挑战性，因为 PVA 可溶于水。在这项研究中，通过接枝香草醛的 PVA（VPVA）、疏水性腐殖酸（HA）和 Fe 离子的络合作用，制备了在土壤中具有优异降解性和在水相环境中具有高机械强度的 PVA 基超分子塑料（此后表示为 VPVA-HA-Fe 配合物）。通过使用刀片涂层法，可从 VPVA-HA-Fe 配合物的溶液中轻松制备大面积的 PVA 基塑料。高密度的氢键和配位相互作用，以及自组装的 Fe 配合的 HA 纳米粒子的增强作用，有利于制备断裂强度约为 85.0 MPa 的 PVA 基塑料。在室温下浸入水中 7 d 后，PVA 基塑料的断裂强度约为 26.2 MPa，与干燥状态下的聚乙烯相当。此外，由于氢键和配位相互作用的可逆性，VPVA-HA-Fe 塑料是可回收的，并且可以方便地加工成具有所需形状的塑料产品。在土壤中放置约 108 d 后，PVA 基塑料完全降解为无毒物质，无需人工干预。
