Research On Improving Ageing Resistance For Nitrile Butadiene Rubber

Lanzhou Petrochemical Company has two sets of nitrile rubber plants,their production capability is 15,000 tons/year and 50,000 tons/year.The quality and yield of the two nitrile rubber plant are at leading position in domestic enterprises.However,the molecular and anti-aging properties of nitrile rubber have great influenced the products' and have reduced the economic benefits.How to improve the nitrile rubber anti-aging properties is an important research topic.The emulsion copolymerization between polymerization ageing resistant and butadiene and acrylonitrile at 5-20?,NBR was obtained with 27%bound AN content and 1%bound antioxidant content.The main factors are investigated:the effect of three different initiator,three different oxidizer and their dosage,different kinds of reactive tioxidant and its dosage,emulsifier and reductant on the copolymerization rate and emulsion physical performance and the NBR rubber performance were studied all.The effect on the copolymerization rate and emulsion physical performance and the NBR rubber performance by the different rising copolymerization temperature ways,the dosage and different addition ways of molecule weight regulator on rubbers properties were also investigated.The optimum polymerization ingredient and polymerization condition s has been determined.The results indicates that reactive antioxidant slow the copolymerization rate remarkably.The NAPM could copolymerization with butadiene and acrylonitrile by optimizing the initiator,regulator,reaction age resistant,emulsifier and the controlling of copolymerization temperature.The optimum dosage of NAPM is 1.75%,The ratio of isopropyl benzene hydroperoxide/Rongalit/EDTA(FeNa)=0.10:0.0125:0.125,the copolymerization rate is fast and the emulsion stability are optimum,when the colopholic potassium soap is 4.6-5.0%,the emulsion have a high Maron stability.When the dosage o f TDM is 0.48%,and addition ratio of TDM is 23.1%,the mooney viscosity index and gel content in rubber is in reasonable range.The copolymerization temperature increase by the equation 5?×1h+5?80C.The NBR plays excellent properties;the result of absorption oxygen test is 0.239 at 100? and standing 100h.