原位生成甲基丙烯酸锌增强天然橡胶的结构和性能

Structure and properties of natural rubber vulcanizates reinforced by in situ prepared zinc dimethacrylate

用ZnO与甲基丙烯酸(MAA)在天然橡胶(NR)基体中原位生成甲基丙烯酸锌(ZDMA),并在硫化剂过氧化二异丙苯(DCP)作用下制备了NR/ZnO/MAA纳米复合材料。用傅里叶变换红外光谱法、X射线衍射法、能量色散X射线法和扫描电子显微镜法分析了NR在混炼和硫化过程中的结构和形态变化,并研究了硫化胶的力学性能。结果表明,在NR混炼过程中加入摩尔比为0.5的ZnO/MAA,可以原位生成ZDMA;在硫化过程中,ZDMA在DCP作用下发生复杂化学反应,形成界面紧密结合的纳米复合材料,导致硫化胶的力学性能显著提高。当ZnO/MAA为40份时,硫化胶的拉伸强度、撕裂强度、扯断伸长率分别为30.6MPa,54.7kN/m,410%,其增强效果优于直接添加ZDMA。

Zinc dimethacrylate (ZDMA) was in situ prepared in mixing process of natural rubber with ZnO and methacrylic (MAA), and used to obtain NR/ZnO/MAA vulcanizates by dicumyl peroxide (DCP) as curing agent. The structure and morphologies of compound were studied by Fourier transform-infrared spectroscopy,X-ray diffraction、energy-dispersion X-ray and scanning electron microscope in rubber mixing and vulcanization process, then the mechanical properties were studied.The results showed that ZDMA could be in situ prepared by ZnO and MAA (ZnO/MAA mole ratio 0.5) added.During the curing process,there had complex chemical reaction,therefore, it could form a kind of nano-composite material with tight combination at interface, the NR vulcanizates could get the good mechanical properties. At the formulation of DCP 1.5 phr and ZnO/MAA 40 phr,the tensile strength,tear strength and elongation at break were 30.6 MPa,54.7 kN/m,410% respectively.The NR vulcanizates reinforced by ZDMA prepared in situ had better mechanical properties than those of reinforced by ZDMA added directly.