Suntako Rudeerat
Department of Physics, Faculty of Liberal Arts and Science, Kasetsart University Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.
Polymers (Basel). 2022 Apr 27;14(9):1767. doi: 10.3390/polym14091767.
The interaction between silica and rubber is very important for the production of high performance rubber. Silica surface modification with silane is a general method that aims to enhance the reinforcement efficiency of silica. In this study, a new surface modification of silica with silane and the chemical reaction with sulfenamide accelerator were investigated. The (gamma-glycidoxypropyl) trimethoxysilane (GPTMS) was used as a silane. The N-cyclohexyl-2-benzothiazole sulfenamide (CBS) and N-tert-butyl-2-benzothiazole sulfenamide (TBBS) were used as sulfenamide accelerators. The FTIR spectra results indicate that the GPTMS and sulfenamide accelerators (CBS and TBBS) could successfully form on the silica surface. The new modification is capable of significantly enhancing the reinforcement efficiency; more than the conventional silica surface modification by GPTMS (m-silica). In particular, modifying silica with GPTMS and TBBS (m-silica-TBBS) is capable of increasing the crosslink density and mechanical properties more efficiently than modified silica with GPTMS and CBS (m-silica-CBS), m-silica, silica (unmodified), and unfilled natural rubber. This is due to the presence of GPTMS, which plays an important role in increasing the chemical cross-linking in the rubber chain, while TBBS, as a sulfenamide accelerator, provides a high accelerator to sulfur ratio, which is able to give a more efficient vulcanization. With the reinforcement of a rubber rail pad with silica surface modification, the results indicate that the increment of m-silica-TBBS loading could reduce the deformation percentage of the rubber rail pad more than m-silica and m-silica loading. This is mainly due to the static spring improvement, which results in a stiffer material.
二氧化硅与橡胶之间的相互作用对于高性能橡胶的生产非常重要。用硅烷对二氧化硅进行表面改性是一种旨在提高二氧化硅增强效率的常用方法。在本研究中，研究了一种用硅烷对二氧化硅进行的新型表面改性以及与亚磺酰胺促进剂的化学反应。使用（γ-缩水甘油氧基丙基）三甲氧基硅烷（GPTMS）作为硅烷。使用N-环己基-2-苯并噻唑亚磺酰胺（CBS）和N-叔丁基-2-苯并噻唑亚磺酰胺（TBBS）作为亚磺酰胺促进剂。傅里叶变换红外光谱（FTIR）结果表明，GPTMS和亚磺酰胺促进剂（CBS和TBBS）能够成功地在二氧化硅表面形成。这种新型改性能够显著提高增强效率；比通过GPTMS进行的传统二氧化硅表面改性（m-二氧化硅）更有效。特别是，用GPTMS和TBBS改性的二氧化硅（m-二氧化硅-TBBS）比用GPTMS和CBS改性的二氧化硅（m-二氧化硅-CBS）、m-二氧化硅、未改性的二氧化硅和未填充的天然橡胶更能有效地提高交联密度和机械性能。这是由于GPTMS的存在，它在增加橡胶链中的化学交联方面起着重要作用，而TBBS作为亚磺酰胺促进剂，提供了高促进剂与硫的比例，能够实现更有效的硫化。对橡胶轨枕进行二氧化硅表面改性增强后，结果表明，与m-二氧化硅和二氧化硅负载量相比，增加m-二氧化硅-TBBS负载量可以降低橡胶轨枕的变形百分比。这主要是由于静态弹簧性能的改善，从而使材料更硬。
