改性钢渣/橡胶复合材料导热性能及耐久性研究

利用自制钢渣助磨改性剂处理热闷渣、电炉渣与风淬渣，将改性后的钢渣微粉与炭黑、橡胶基体等复合形成改性钢渣/橡胶复合材料.采用导热系数仪，测定三种改性钢渣/橡胶复合材料热氧老化1、3、5、7、9、11 d的导热系数；根据Young’s与Flory方程计算出三种改性钢渣/橡胶复合材料热氧老化前后的接触角θ与交联密度；采用热重分析仪(TGA)、场发射扫描电镜(SEM)进行热氧老化前后分析.未热氧老化时，在三种改性钢渣/橡胶复合材料中改性电炉钢渣/橡胶复合材料的导热系数最低，为0.187 W·m^-1·K^-1，是因为改性电炉渣粒中位径(d₅₀)最小，即3.49μm，形成更致密的胶裹渣结构，不易形成导热通路，使其导热系数降低.热氧老化时，破坏胶裹渣结构，改性电炉渣/橡胶复合材料形成的孔隙大，分散性最好，降低界面热阻，更易形成导热通路，使其导热系数最高.热氧老化后，橡胶复合材料表面粗糙度变大且存在较长裂纹与较深孔洞，导致橡胶复合材料吸水性增加，接触角下降.由于改性热闷渣的粒径最大，在热作用下氧气更容易进入橡胶复合材料中与橡胶分子链(双键...

Studies on thermal conductivity and durability of modified steel slag/rubber composites

Modified steel slag powder was used to create a modified steel slag/rubber composite material using self-made steel slag grinding modifier and combining it with carbon black and rubber matrix to treat hot braised steel slag, electric furnace steel slag, and air-quenched steel slag. Next, the thermal conductivity of the three types of modified steel slag/rubber composites was measured using a thermal conductivity instrument at 1, 3, 5, 7, 9, and 11 days. The surface contact angle θ and crosslinking density of the above composites were calculated using Young’s and Flory’s equations before and after thermal oxygen aging, and their changes were analyzed using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). As a result, the thermal conductivity of the modified electric furnace slag/rubber composite material was the lowest 0.187 W·m?1·K?1]. Among them, the median diameter (d₅₀) of the modified electric furnace slag particles was the smallest (3.49 μm) without thermal oxygen aging, easily forming a compact structure of rubber-wrapped slag, but more challenging to develop thermal conductivity paths that reduced thermal conductivity. In the process of thermal oxygen aging, the structure of rubber-wrapped slag was destroyed. While the modified electric furnace slag/rubber composite material had large pores and the best dispersibility, which reduced interface thermal resistance and easily formed thermal conductivity paths, its thermal conductivity was the highest. After thermal oxygen aging, it was found that long cracks, deep holes, and increased roughness lying on rubber composite material surface increase the water absorption and decrease the contact angle. Besides, due to the largest particle size of the modified hot braised slag, oxygen is more likely to enter the rubber composite material under the heat action to react with the rubber molecular chain (double bond) to generate free radicals, thus raising molecular weight and growing crosslinking density. The modified air-quenched slag had the highest basicity (3.3), was detrimental to the vulcanization process, and was prone to forming an unstable carbon layer, resulting in more secondary combustion and a lower crosslinking density. Moreover, the mass fraction of residual material called carbon residue was only 1.02% at 800 ℃ and it had the worst durability after thermal oxygen aging.