Study On Properties Of NBR/EPDM Compounds

The effects of curing system, mixing technology, compatilizer and methylacrylate on properties of NBR/EPDM compounds were studied in this thesis.The current study indicates that the combination of sulfur curing system and peroxide curing system has high performance on vulcanizing of NBR/EPDM blends, and the relevant experiments proved that NBR/EPDM vulcanizates would have the best mechanical properties with the formulation of DCP 2.8 phr,S 1 phr,TMTD 0.8 phr,CZ 0.4 phr. With the increasing amount of Carbon Black, NBR/EPDM vulcanizates tensile strength first increased and then decreased, and showed the best overall performance with the amount of Carbon Black 50 phr. As the unsaturation of EPDM increased, the covulcanizing performance of NBR/EPDM blends improved, while there was a decline in the aging properties. Mechanical properties of any single NBR or EPDM had better performance than those with different ratios of NBR/EPDM blends. Reinforcement was achieved by blends roasting treatment and the SEM photographs also showed that the compatibility was improved by the treatment.Mechanical properties of NBR/EPDM blends, such as tensile strength, can be reinforced by a small amount of compatibilizer EVA, CPE adding, and the optimum dosage of EVA is 0.5 phr while CPE is 1 phr. Curing rate and degree could be improved by Zinc acrylate (ZDA). 5phr ZDA could achieve the best performance. For NBR/EPDM blends which contain 5phr ZDA, with blends roasting treatment, sulfur curing system, peroxide curing system and the combination of the two would be reinforced better than those without treatments, especially the sulfur curing system.Experiments shows that curing rate and degree of NBR/EPDM blends with in-situ reaction of natrium methacrylate (NaMAA) improved obviously compared to the blends that generated from EPDM mother blends first. The best reinforcement of NBR/EPDM blends with in-situ reaction would be achieved when the theoretical production of NaMAA was 40 phr. SEM photograph analysis shows NBR/EPDM compounds filled by in-situ NaMAA with NBR and EPDM blended first would have the tightly integrated of cross-section, a more uniform structure and appearance, compared to the EPDM mother blends. It also indicated that in-situ generation of NBR/EPDM blends compatibility have a better effect on NBR/EPDM blends.