Lin Xiuyi, Yu Jing, Li Hedong, Lam Jeffery Y K, Shih Kaimin, Sham Ivan M L, Leung Christopher K Y
Nano and Advanced Materials Institute, Hong Kong Science Park, Shatin, Hong Kong, China; Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
J Hazard Mater. 2018 Sep 5;357:40-52. doi: 10.1016/j.jhazmat.2018.05.046. Epub 2018 May 26.
As an important portion of the total plastic waste bulk but lack of reuse and recycling, the enormous amounts of polyethylene terephthalate (PET) solid wastes have led to serious environmental issues. This study explores the feasibility of recycling PET solid wastes as short fibers in Strain-Hardening Cementitious Composites (SHCCs), which exhibit strain-hardening and multiple cracking under tension, and therefore have clear advantages over conventional concrete for many construction applications. Based on micromechanical modeling, fiber dispersion and alkali resistance, the size of recycled PET fibers was first determined. Then the hydrophobic PET surface was treated with NaOH solution followed by a silane coupling agent to achieve the dual purpose of improving the fiber/matrix interfacial frictional bond (from 0.64 MPa to 0.80 MPa) and enhancing the alkali resistance for applications in alkaline cementitious environment. With surface treatment, recycling PET wastes as fibers in SHCCs is a promising approach to significantly reduce the material cost of SHCCs while disposing hazardous PET wastes in construction industry.
作为塑料总废弃物中的一个重要部分，但缺乏再利用和回收利用，大量的聚对苯二甲酸乙二酯（PET）固体废弃物已导致严重的环境问题。本研究探讨了将PET固体废弃物作为短纤维用于应变硬化水泥基复合材料（SHCCs）中的可行性，SHCCs在拉伸时表现出应变硬化和多裂缝特性，因此在许多建筑应用中比传统混凝土具有明显优势。基于微观力学建模、纤维分散性和耐碱性，首先确定了回收PET纤维的尺寸。然后用NaOH溶液处理疏水性PET表面，再用硅烷偶联剂处理，以达到双重目的，即改善纤维/基体界面摩擦粘结（从0.64MPa提高到0.80MPa）并增强在碱性水泥环境中应用时的耐碱性。通过表面处理，将PET废弃物作为纤维用于SHCCs是一种很有前景的方法，既能显著降低SHCCs的材料成本，又能在建筑行业中处置有害的PET废弃物。
