改性天然沸石对橡胶复合材料性能的影响

Effect of modified natural zeolite on the properties of rubber composites

摘要:

为了提高沸石在橡胶中的分散，增强沸石与橡胶的界面相互作用，本文采用硝酸（H）和双-（γ-三乙氧基硅基丙基）四硫化物（S）对天然沸石（NZ）进行复合改性（S-HNZ），然后将改性沸石与天然橡胶（NR）混炼制备沸石/天然橡胶复合材料，研究不同改性沸石对天然橡胶性能的影响。采用FTIR、XRD、SEM等测试手段对改性前后NZ的结构进行表征，研究了橡胶复合材料的硫化性能，动态热机械性能（DMA）及力学等性能。结果表明：经酸处理后天然沸石（HNZ）骨架脱铝呈疏水性，且硅烷成功接枝到天然沸石表面。添加S-HNZ的橡胶复合材料焦烧时间和正硫化时间均缩短，硫化反应速率加快；另外，与NR相比，NR/S-HNZ的300%定伸应力和抗拉强度分别提高了46.7%和10.8%；DMA结果显示，NR/S-HNZ储能模量（E'）和玻璃化转变温度（Tg）均高于NR，表明经复合改性后，复合材料的交联密度增加，形成较强的交联网络，极大提高了沸石与橡胶大分子链之间的界面结合力。

Abstract:

In order to improve the dispersion of zeolite in rubber and enhance the interfacial interaction between zeolite and rubber. In this paper, natural zeolite (NZ) was modified by bis - (γ -triethoxylsilyl propyl) tetrasulfide (S) and nitric acid（H）, and then modified zeolite (S-HNZ) and natural rubber (NR) were mixed to prepare modified NR/NZ composites. The effects of different modified zeolite on the properties of natural rubber were studied. The structure of natural rubber and modified zeolite was characterized by Fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). The vulcanization properties, dynamic thermal mechanical properties (DMA) and mechanical properties of the rubber composite were investigated. The results showed that the framework of natural zeolite (HNZ) was dealuminated and becomes hydrophobic after acid treatment, and silane was successfully grafted onto the surface of natural zeolite. The scorch time and curing time of rubber composite with S-HNZ were shortened, which was accelerated the curing reaction rate of rubber composite. In addition, compared with those of NR composites, the stress at 300% strain and tensile strength and properties of NR/S-HNZ composites were increased by 46.7% and 10.8%, respectively. DMA results revealed that NR/S-HNZ storage modulus (E') and glass transition temperature (Tg) were higher than NR, indicating that after compound modification, the cross-linking density of the composite material increases, forming a stronger cross-linking network, which greatly improves the interfacial bonding strength between zeolite and rubber macromolecular chain.