Study On Preparation,Structure And Properties Of Nitrile-butadiene Rubber/Hindered Phenol Composites

In this paper, a new crosslinked composite contain NBR (or NBVC) and hindered phenol (AO-60and AO-80) was successfully prepared, which exhibited high damping and mechanical properties. The effects of the process technics, kind and loading of hindered phenol, acrylonitrile content in NBR, and the vulcanization system to the structure and properties of composites were investigated.In the NBVC/AO-80composites, AO-80formed a much fine dispersion: most of AO-80dissolved in the matrix and the undissolved AO-80dispersed as submicron particles with the average size from tens of nanometer to0.3μm. Because of the hydroxyl group of the amorphous AO-80and the polar group of the matrix formed strong intermolecular interaction, the glass transition of the composites obviously shift toward to the high temperature with the loading of AO-80increased; most importantly, the value of tgδ increased remarkably as the content of AO-80content increasing. The composites exhibited high damping properties at the high temperature and low frequency condition. For the fine dispersion and strong intermolecular interaction, NBVC/AO-80 crosslinked composites exhibited high tensile strength.It was found that the acrylonitrile content in NBR was a fatal factor to the compatibility of AO-60and NBR. When the acrylonitrile content smaller than41%(which in N220S), such as N230S, N240S and DN401, AO-60would have good compatibility with the matrix.AO-60formed much fine dispersion in the N230S and NBVC matrix: part of AO-60dissolved in the matrix and the undissolved formed submicrometer particles with the size of250nm. And in the NBVC/AO-60composites, the AO-60aggregation particles contain much PVC molecules. The glass transition temperature of N230S/AO-60crosslinked composites increased as the loading of AO-60increasing; but in the NBVC/AO-60composites, the glass transition temperature didn’t show a obviously increasing when the AO-60content at50phr. N230S/AO-60crosslinked composites showed only one transition and the value of tgδ increased with the increasing of AO-60content. But the NBVC/AO-60composites showed two transitions on the tgδ-temperature curves and the transition at90℃was assigned to the dissociation of the intermolecular interaction between AO-60and PVC.Using brominated phenolic resin (BPF) as the cure agent could improve the compatibility of AO-60and N220S, and there was no holes in the N220S/BPF/AO-60composites, AO-60dispersed as submicrometer particles with the size of0.2～0.4μm in the matrix. The tgδ～temperature curves of N220S/BPF/AO-60composites showed two transitions, that is the glass transition of the composites and the transition of the amorphous AO-60. But the effect of BPF to the structure and dynamic properties of N230S/AO-60was slightly. These two kind composites exhibited high mechanical properties,...