Ling Zhao, Chang Su, Qian Wang, Hai-Lin Fei, Yu-Jia Fan, Liang-Jun Chen, Yi-Qun Fang, Yan Bai, Hao Zhang, Hong-Ming Long
Controlling the consumption of talc powder (TP) and promoting the resource utilization of pressurized-hot steel slag (PSS) have become urgent tasks under current environmental policies. An innovative interfacial modification strategy based on free-radical chemistry was used to modify PSS, obtaining modified pressurized-hot steel slag (MPSS) with a lower contact angle and surface energy and enhancing the compatibility of MPSS with the wood-plastic matrix through both physical and chemical crosslinking to improve the mechanical properties and thermal stability of wood-plastic composites (WPCs). Particularly, the MPSS replacing TP at 50% (W2) achieved the highest crosslinking density (0.40 mol cm-3). Meanwhile, MPSS also served as a heterogeneous nucleation site, increasing crystallinity by 34.4% compared with the sample without MPSS (W0, as a control). Consequently, W2 exhibited optimal mechanical properties, including tensile, flexural, and impact strengths improved by 33%, 30.7%, and 91.4% relative to W0, respectively. Notably, the flexural strength of W2 was 31.9MPa,20MPa higher than the requirement in GB/T 24137-2009 standard and 30 MPa higher than the value in JGJ/T 478-2019 standard, demonstrating its potential for indoor and outdoor decorative panels and constructive boards. Besides, W2 with high crystallinity facilitated the formation of dense and stable carbon layers. In MPSS, the high-melting Al2O3 and MnO acted as the framework for carbon layers, and FexOy,CaO, and MgO accelerated its formation, further enhancing thermal stability. PSS was successfully applied in WPCs by partially replacing expensive and non-renewable TP as a filler in WPCs.
