不同金属氧化物在原位生成技术改性HNBR中的作用研究

Influence of different metal oxides on HNBR modified by in-situ synthesis

分别采用氧化镁(MgO)、氧化钙(CaO)、氧化锌(ZnO)与丙烯酸(AA)原位生成丙烯酸盐改性氢化丁腈橡胶(HNBR),研究不同金属氧化物对原位生成技术改性HNBR的影响。采用傅里叶红外光谱分析3种原位生成不同丙烯酸盐改性HNBR的结构;采用扫描电子显微镜观测丙烯酸盐在HNBR中的分布;并采用平衡溶胀法表征了未改性HNBR与3种改性HNBR的总交联密度、共价交联密度与离子交联密度,并对比其力学性能。结果表明:原位生成丙烯酸盐在HNBR中产生的离子键与过氧化物引发的共价键协同作用,形成"离子型共价键合"使HNBR性能得到很大程度的提升;不同金属氧化物与HNBR相容性的差别影响了丙烯酸盐在基体中的含量与分散,导致离子交联密度不同,继而影响复合材料的力学性能;原位生成的3种丙烯酸盐中,丙烯酸锌(ZnDA)对HNBR的改性效果最好,在基体中分散均匀,相容性好,离子交联密度与总交联密度最高,力学性能最好;丙烯酸镁(MgDA)次之;丙烯酸钙(CaDA)最差。

Hydrogenated nitrile-butadiene rubber(HNBR) was modified by in-situ formation of acrylate with magnesium oxide(MgO),calcium oxide(CaO),zinc oxide(ZnO) and acrylic acid(AA).The effect of different metal oxides on HNBR modified by in-situ synthesis was studied.Fourier transform infrared spectroscopy(FT-IR) was used to analyze the structure of HNBR modified by three kinds of in-situ synthesized acrylates.The distribution of acrylate in HNBR was observed by scanning electron microscope(SEM).The total crosslinking density,covalent crosslinking density and ionic crosslinking density of pure HNBR and three kinds of modified HNBR were characterized by the method of equilibrium swelling,and compared their mechanical properties.The results shown that the ionic bond formed by in-situ acrylate in HNBR and the covalent bond initiated by peroxide cooperate to form “ionic covalent bonding” which greatly improved the performance of HNBR.The difference of compatibility between different metal oxides and HNBR affected the content and dispersion of acrylate in the matrix,resulting in different ionic crosslinking density,which further affected the mechanical properties of the composite.Among the three kinds of in-situ synthesized acrylates,ZnDA had the best modification effect on HNBR,with uniform dispersion in the matrix and good compatibility.The ionic crosslinking density and total crosslinking density were the highest,and the mechanical properties were the best.MgDA was the second,and CaDA was the worst.