羧基丁腈橡胶/聚氧化乙烯改性埃洛石复合材料的力学损耗性能

Mechanical loss properties of carboxylated nitrile rubber/polyethylene oxide modified halloysite composites

采用具有柔性分子链的聚氧化乙烯(PEO)改性埃洛石纳米管(HNT),研究了羧基丁腈橡胶(XNBR)/改性HNT(PHNT)复合材料的结构与性能。傅里叶变换红外光谱分析结果显示,XNBR/PHNT复合材料中的游离羧基伸缩振动峰较纯XNBR向低波数方向移动了2 cm^(-1),且峰强度增强,而腈基伸缩振动峰强度相对减弱,表明PEO与XNBR之间存在一定的氢键作用。动态力学分析结果表明,XNBR/PHNT复合材料的损耗因子最大值较之未改性HNT填充者有明显提高,说明PEO能够消除HNT对XNBR损耗下降的作用;且改性复合材料在高温区域(50℃附近)由于氢键结构的松弛造成了额外的能量耗散,进而呈现出更高的损耗值。此外,XNBR/PHNT复合材料的综合力学性能要优于XNBR。

Polyethylene oxide( PEO) having flexible macromolecule chain was utilized to modify halloysite nanotube( HNT), and the structure and properties of carboxylated nitrile rubber( XNBR)/PEO modified HNT( XNBR/PHNT) composites were studied. The results of Fourier transform infrared spectroscopy indicated that stretching vibration peak attributed to the free carboxyl groups in XNBR/PHNT composite was strengthened and shifted to lower wavenumber about 2cm^-1,and the peak intensity of nitrile groups was weakened relative to those of XNBR,showing the presence of hydrogen bonds between PEO and XNBR molecular chains.The dynamic mechanical analysis results showed that the maximum loss factor of XNBR/PHNT composite was significantly higher than that of unmodified HNT composite, indicating that PEO molecules could eliminate the influence of HNT on XNBR in the decrease of loss factor. Otherwise,the relaxation of hydrogen bonds caused excesses energy dissipation,which leaded to higher loss factors of the modified composite in the high-temperature region( around50℃). Furthermore,the comprehensive mechanical properties of XNBR/PHNT composites were better than those of XNBR.