促进剂DPG在白炭黑填充天然橡胶胶料混炼中加料顺序对胶料性能的影响

Effect of Adding Sequence of Accelerator DPG in the Mixing of Silica-filled Natural Rubber Compound on Compound Properties

研究促进剂DPG在白炭黑填充天然橡胶(NR)胶料混炼中加料顺序对胶料性能的影响。结果表明:促进剂DPG与NR、白炭黑和硅烷偶联剂同时加入混炼能够参与和促进硅烷化反应,改善白炭黑与NR之间的相容性,减轻白炭黑聚集,因此可降低Payne效应,提高胶料的耐热老化性能,但因其参与硅烷化反应而减小了参与硫化反应的量,导致硫化速率降低,焦烧时间延长,同时由于交联密度下降导致硫化胶的耐磨性能、300%定伸应力和撕裂强度降低及60℃时的损耗因子增大,在配方开发和混炼工艺设计时,应考虑适量补充促进剂DPG在前期混炼阶段加入时的损耗。

The effect of the adding sequence of the accelerator DPG in the mixing of silica-filled natural rubber(NR)compounds on the properties of the compound was studied.The results showed that the accelerator DPG participated in and promoted the silanization reaction when it was mixed with NR,silica and silane coupling agent at the same time,and thus the compatibility between silica and NR was improved,and the silica aggregation was reduced.Therefore,the Payne effect was reduced and the heat aging resistance of the compound was improved.However,due to its participation in the silanization reaction,the amount involved in the vulcanization reaction was reduced,resulting in a decrease in the vulcanization rate and a prolonged scorch time.At the same time,due to the decrease in cross-linking density,the wear resistance,modulus at 300%elongation and tear strength of the vulcanizate decreased,and tanδat 60℃increased.Therefore,appropriate supplementary accelerators should be considered during formulation development and mixing process design.