Preparation And Characterization Of Electric CeO₂/PANI Rubber Composite

Chlorinated polyethylene rubber is widely used in the manufacture of wire and cable,hydraulic hose, automotive hose, tape, modifying PVC pipe, magnetic materials owing toits excellent properties such as thermal oxidative aging resistant, ozone aging resistant,acid and chemical resistant and harmless to environment. However, as functional rubberhas been vastly applied, the application of traditional rubber is greatly restricted.Firstly, in this study cerium oxide (CeO2) power was modified by stearic acid. Thenwe investigated the influence of the experiment conditions (modification time,temperature and amount of stearic acid) on the activation index. Secondly,dodecylbenzene sulfonic acid (DBSA) and hydrochloric acid (HCl) were selected asdoping agents for preparing co-doped conductive polyaniline (PANI). In this section, westudied the influence of the dosages of HCl, DBSA and ammonium persulfate (APS) andthe reaction temperature on the conductivity of PANI. Thirdly, taking chlorinatedpolyethylene rubber (CM) as the matrix, CeO2/PANI/CM composites were prepared bymechanical blending. The effects of different percentages of PANI on the conductivity andmechanical properties of the composites were investigated together with the impact ofCeO2on the performance of the conducting rubber.FTIR, SEM, DSC, TG, XRD and other testing methods were used to characterize theproducts. The results showed that when the amount of stearic acid was4%, modificationtemperature was60℃and time was60min, the modification effect of cerium oxide wasthe best. The modified CeO2powder exhibited good dispersibility and low agglomeration.The main doping PANI reaction occurred on quinone nitrogen atom, which made thepolymer chains produce conjugative and inductive effects. The two effects made theelectron cloud density of polymer chains decreased, the electron cloud rearranged and thecharge delocalized to the aromatic ring, resulting in high conductivity. When6parts ofPANI was added, the conductivity of the rubber reached the maximum,9.2×10-6S/cm.The addition of PANI to the rubber is to increase properties of the rubber, such as tearingstrength, tensile modulus and hardness. The conductivity and mechanical properties of theconductive rubber was improved by the addition of CeO2. While the modified CeO2 showed better result than the pure one mainly due to the improved compatibility anddispersibility of the modified CeO2in the rubber matrix. CeO2particles in the rubbermatrix achieved good dispersion and reduced the formation of defects, thus improved theperformance of the rubber.