基于FTIR与XRD的改性脱硫灰取代部分炭黑制备复合橡胶的补强机理研究

Study on Reinforcement Mechanism of Composite Rubber Using Modified Desulfurization Ash Replacing Partial Carbon Black by FTIR and XRD

脱硫灰是半干法脱硫的主要副产品,其利用难度大且成本高,导致大量脱硫灰以直接堆放和填埋的方式处理,不但造成环境污染,而且浪费潜在资源。炭黑(8000元·t^-1)与白炭黑(6000元·t^-1)是常用的橡胶补强填料,生产工艺繁杂,消耗大量能源和资源,导致成本较高。面对上述问题,如何利用脱硫灰开发一种价格低廉的无机橡胶补强填料,既是固体废弃物高附加值利用的重要途径之一,也是橡胶企业大幅降低填料成本提高经济效益的重要途径之一。由于脱硫灰属于无机材料,橡胶属于有机材料,为了更好的降低脱硫灰界面与橡胶界面(无机界面/有机界面)的不相容性,需要对脱硫灰进行化学改性处理,以提高脱硫灰代替部分炭黑制备橡胶的力学性能。该研究创新性以硅烷偶联剂Si69、硅烷偶联剂KH550与脱硫灰制备改性脱硫灰,然后以改性脱硫灰取代部分炭黑制备复合橡胶。根据国家与行业标准测试复合橡胶的力学性能,如拉伸强度、撕裂强度和硬度。利用扫描电子显微镜(SEM)对复合橡胶的微观形貌进行测试与分析,傅里叶变换红外光谱仪(FTIR)对改性脱硫灰的组成结构进行测试与分析,X射线衍射仪(XRD)对改性脱硫灰的矿物组成进行测试与分析,以揭示硅烷偶联剂Si69与硅烷偶联剂KH550协同对脱硫灰的改性机理,以及改性脱硫灰对复合橡胶的补强机理。结果表明:采用硅烷偶联剂KH550与硅烷偶联剂Si69协同改性脱硫灰,其取代炭黑的增强效果最佳,即复合橡胶的拉伸强度为20.36MPa、撕裂强度为45.71kN·m^-1和邵尔A硬度为66;硅烷偶联剂KH550与硅烷偶联剂Si69协同改性脱硫灰,不仅保持脱硫灰依然良好的碱性,有利于对复合橡胶起到增强效果;而且可以改善脱硫灰的表面特性与结构,提高改性脱硫灰与丁苯橡胶的无机界面/有机界面相容性。

As main by-product of semi-dry desulfurization technology, desulfurization ash is very difficult in utilizing and cost consumable, which cannot be disposed in direct stacking and landfill, causing environmental pollution and the waste of potential resources. Carbon black(8 000 yuan·ton^-1) and white carbon black(6 000 yuan·ton^-1), as the commonly used rubber reinforcing filler, can only be prepared by using complicated process and always leads to large consumption of energy and resources, resulting in higher costs. Thus, the development of desulfurization ash into low-cost inorganic rubber reinforcing fillers has become one of main methods to achieve the sustainable development of resources and enhance economic performance by using high value-added utilization of solid wastes and reduce cost of fillers in rubber industry to a great extent, respectively. The desulfurization ash is organic while rubber is inorganic. Therefore, it is necessary to conduct chemical modification for desulfurization ash to weaken incompatibility of interface(organic/inorganic) between them. In this paper, the modified desulfurization ash was prepared by silane coupling agent Si69, silane coupling agent KH550 and desulfurization ash. Then, composite rubber was prepared by replacing part of carbon black with modified desulfurized ash. Next, mechanical properties of composite rubber, such as tensile strength, tear strength and shore hardness of composite rubber was tested by referring to national and industry standards. Specially, microstructure of composite rubber was characterized and analyzed by scanning electron microscope(SEM), composition structure of modified desulfurization ash was characterized and analyzed by using fourier transform infrared spectrometer(FTIR), and mineral composition of modified desulfurization ash was characterized and analyzed by using X-ray diffractometer(XRD), so as to reveal the modification mechanism of both agents as well as reinforcement mechanism of desulfurization ash for composite rubber. The results show that when desulfurization ash was modified by applying both silane coupling agent Si69 and silane coupling agent KH550, the best enhancement effect occurs with tensile strength, tear strength and shore A hardness as 20.36 MPa, 45.71 kN·m^-1 and 66, separately. The desulfurization ash is modified by combined action of both silane coupling agent Si69 and silane coupling agent KH550 not only can still maintain good alkalinity, which can enhance reinforcement effect of composite rubber, but also can improve surface property and structure of desulfurization ash, so as to enhance the compatibility of organic/inorganic interface between modified desulfurization ash and styrene butadiene rubber.