一步法制备可再生塑料薄膜及性能研究

目的利用餐厨垃圾四季豆,制备可再生塑料包装膜。方法以餐厨垃圾四季豆为模型,采用三氟乙酸(TFA)为溶剂,一步法将其浸泡溶解制备可再生塑料薄膜。采用红外光谱(FT-IR)、扫描电镜(SEM)和原子力显微镜(AFM)对薄膜结构和形貌进行表征;利用电感耦合等离子体-质谱仪(ICP-MS)、X射线光电子能谱(XPS)和X射线衍射光谱(XRD)对膜中存在矿物质元素的含量、存在形式及晶体结构进行探究和分析。结果得到四季豆可再生塑料薄膜中存在纤维素和木质素特征的红外图谱;在薄膜的断面,纤维素和木质素以不规则条纹状孔道分布;薄膜表面存在无机颗粒聚集体,薄膜表面粗糙度为29.6 nm;可再生塑料薄膜中存在多种微量矿物质元素,并主要以Ca3(PO4)2,MgO,MgCO3,KBr的形式存在于可再生塑料薄膜中,从而将植物中天然的矿物质元素引入可再生塑料薄膜。通过对可再生塑料薄膜力学性能的探讨,发现与微晶纤维素复合后,四季豆可再生塑料薄膜的拉伸强度由1.5MPa到37.7 MPa,断裂伸长率由133%到13%。结论四季豆废料可以在极大尺度内调控强极性可再生膜材的性能。复合膜的模量处于工程聚合物和弹性体与淀粉基天然聚合物之间的空白地带,填补了合成聚合物和淀粉基聚合物的性能差距。为我国餐厨垃圾的再利用提供了新的思路,也为仿生材料和生物质材料的制备提供了新参考。

Preparation and Characterization of Renewable Plastic Film via Direct Immersion

The work aims to prepare renewable plastic packaging film from kitchen garbage kidney bean. The renewable plastic film was prepared by kitchen garbage kidney bean via direct immersion in trifluoroacetic acid (TFA). FTIR, SEM and AFM were used to characterize the structure and morphology of the film. The content, existence form and crystal structure of mineral elements in the film were studied and analyzed by ICP-MS, XPS and XRD. The FTIR indicating the existence of cellulose and lignin in kidney bean renewable plastic film was obtained. The irregular stricture channels were distributed in the cross-section of the film. The aggregation of inorganic particles was found on the film and the surface roughness of the film was 29.6 nm. Various kinds of trace mineral elements existed in the renewable plastic film, mainly in the form of Ca3(PO4)2, MgO, MgCO3 and KBr, so that natural mineral elements in the plant were introduced into the renewable plastic film. From the discussion on the mechanical properties of renewable plastic film, compounded with microcrystalline cellulose, the tensile strength of kidney bean renewable plastic film ranged from 1.5 MPa to 37.7 MPa and the elongation at break ranged from 133% to 13%. The kidney bean wastes can greatly regulate the properties of strong-polar renewable films. The modulus of its composite film lies in the gap between engineering polymers, elastomers and starch-based natural polymers, filling the performance gap between synthetic polymers and starch-based polymers. This study provides a new idea for the recycling of kitchen garbage in China, and new reference for the preparation of biomimetic and biomass materials.