Preparation And Research Of MMT/CB/NBR Composite Material

Nitrile rubber (NBR) is mainly used in oil-resistant sealing products but usually need to be added by fillers to reinforce its properties and to reduce cost.Inorganic filler reinforcement is an important technique in rubber researching and co-reinforcement with two or more inorganic fillers has been a hotspot.Effects of the reinforcements of six different fillers (carbon black (CB),rice husk ash (RHA),sericite (SER),montmorillonite (MMT),attapulgite (AT) and grammite (GRA)) on the mechanical property,crosslink density,fluid resistance,heat aging property and microstructures of the reinforced NBR were comprehensively investigated.The results indicated that the CB and the MMT performed the best overall and were the best to carry out the subsequent experiments.In order to improve the hydrophobic and the disperion properties of CB (modified by the mixture of OA/Si69) and MMT (treated successively by CTAB and Si69),samples treated with different methods were characterized with the aids of hydrophobic test,SEM,FTIR and XRD to determine the best modifying conditions.The results showed that under the circumstance of OA/Si69=10/10 (Wt%),90min,80℃,the modified CB demonstrated the optimum hydrophobic property and the minimum average particle size.While,under the circumstance of Si69/CTAB-20/15 (Wt%),the modified MMT turned hydrophilic to hydrophobic,and its interlamellar spacing increased to 2.153nm from 1.583nm accordingly.NBR reinforced by MCB behaved better than that by CB; OMMT better than MMT as filler.NBRcomposites reinforced by hybrid filler OMMT/MCB with variousratios (0/25,5/20,10/15,10/15,20/5,25/0) were prepared to study the the influence of OMMT/MCB ratio on Mechanical properties,crosslink-density,fluid resistance,heat aging property and microstructure.It found that when the ratio gets 10/15,the OMMT and the MCB performed the best comprehensive performance.Experiments were carried out to study the influence of activating agents on the OMMT/MCB/NBR composite.The result indicated that the activating agent made of ZnO and SAwas still favorable for the S/DCP Vulcanization system.Based on the results aforementioned,ordinary ZnO was replaced by nanoZno as activator and it was found that nano ZnO promoted the composite with reduced dosage.The properties of MMT/CB/NBR composite was tested and found that it met the The standards of 《filled-rubber Sealing Gasket for Auto Engine》.