充油SEEPS/SEBS的力学性能和动态力学性能与结构的关系

Relationship Between Mechanical Properties and Dynamic Thermomechanical Properties and Structure of Oil-Filled SEEPS/SEBS

对具有代表性的多种SEEPS和SEBS进行了结构分析和相对分子质量检测,筛选出化学结构不同但苯乙烯含量相同且相对分子质量接近而具有可比性的SEEPS Kuraray-4055和SEBS YH-502T。通过小角X射线散射、透射电镜和原子力显微镜表征了充油SEEPS与SEBS体系的微观结构,显示SEEPS体系的相尺寸(49.1 nm)和相间距(47.9 nm)比SEBS体系的相尺寸(38.3 nm)和相间距(38.1 nm)大,前者具有更完整的微相分离;结合核磁共振氢谱的结果,发现这是由于SEEPS软段中氢化异戊二烯链段单元的存在使其链段柔顺性高于SEBS所致。根据Instron万能材料试验机和动态力学性能分析结果可知,相同条件下微相分离程度更高的SEEPS体系所具有的力学性能和储能模量均大于SEBS体系。研究结果表明,SEEPS/SEBS的分子结构是影响其充油体系微观结构、力学性能及动态力学性能的主要因素。

A variety of representative SEEPS and SEBS were analyzed for structure and molecular weight.SEEPS Kuraray-4055 and SEBS YH-502T,which have different chemical structures but the same styrene content and similar molecular weight,were selected.The microstructures of oil-extended SEEPS and SEBS systems were characterized by small-angle X-ray scattering(SAXS),transmission electron microscopy(TEM),and atomic force microscopy(AFM).It shows that the phase size(49.1 nm)and phase spacing(47.9 nm)of the SEEPS system are larger than the phase size(38.3 nm)and phase spacing(38.1 nm)of the SEBS system,the SEEPS system has a more complete microphase separation.Combined with the 1H-NMR results,it is found that due to the hydrogenated isoprene segment units in the SEEPS soft segments,which makes the segments more flexible than SEBS.According to the results of the Instron universal material testing machine and DMA,the mechanical properties and storage modulus of the SEEPS system,with a higher degree of microphase separation,are greater than the SEBS system.The results show that the molecular structure of SEEPS/SEBS is the main factor affecting the microstructure,mechanical properties,and dynamic thermomechanical properties of the oil-extended system.The results provide a theoretical basis for the popularization and application of the new SEEPS,and propose new ideas and ways for the preparation of advanced elastomer materials.