Influence of environmentally friendly curing system on properties of railway rubber pad
Chunjiang He, Chuanzhi Chen, Guowen Zhang, Tao Bai, Yongsheng Ji, Dingfeng Pei, Ming Gao, Wei Wang
Abstract
Abstract Improving the aging resistance and elasticity of rubber materials can increase the service life of rubber pads and reduce railway operation costs. The purpose of this work was to improve aging resistance, decrease compression set and ratio of dynamic stiffness to static stiffness ( R d/s ) of railway rubber pads by using environmentally friendly accelerators N‐t‐butyl‐2‐benzothiazole sulfenimide (TBSI) and tetrabenzylthiuram disulfide (TB z TD). The influence of the curing system on the properties of rubber pads was assessed using multiple techniques. Compared to sulfur/tetramethylthiuram disulfide (TMTD) /N‐cyclohexyl‐2‐benzothiazole sulfenamide (CZ), compression set of S/TBSI/TB Z TD decreased to 29.5% from 35.7%, retention of elongation at break after hot air aging increased to 77.7% from 66.1%, and R d/s decreased to 1.82 from 1.85. Thermogravimetry (TG) and derivative thermogravimetry (DTG) analysis indicated that maximum thermal decomposition temperature of TBSI/TB Z TD was higher, which was the reason for the good aging resistance and low compression set results. Rubber processing analysis (RPA) demonstrated that the loss factor of TBSI/TB Z TD was smaller. The rubber cured by TBSI/TB Z TD had a higher crosslinking density and smaller loss factor, which decreased the R d/s . This study provides a reference for preparing of environmentally friendly rubber pads with a low R d/s and long service life.