Study On The Damping And Low Temperature Properties Of TPI/NR Blends

Trans-1,4–polyisoprene with special molecular structure has unique properties, andnow as a special material it is widely researched and developed. The discovery of domesticload titanium precipitated bulk polymerization greatly reduced the cost of TPI, and laid thefoundation for the trans-1,4-polyisoprene scale industrial production. After mixing TPI ingeneral rubber, the basic physical properties of rubber maintained or even increased.Meanwhile dynamic performance, especially heat and flex fatigue performance of rubberimproved significantly, and these are precisely the desired of damping rubber products.However, TPI is a crystalline polymer, and due to the high regularity of its molecular chain, itis easily to crystallize at low temperatures. It would lose elasticity at a temperature muchhigher than the glass transition temperature, so TPI is unable to meet the requirements in coldregions. Low temperature performance limits its application. The mean purpose of this paperis to discuss how to improve low temperature performance of TPI blends without significantreduction in fatigue properties and damping.This paper explores the low-temperature properties and damping of blends by physicalblending and chemical modification methods. The second chapter studies the impact of TPIphysical blending on its damping, dynamic fatigue properties and low temperatureperformance. The effect of these factors such as the amount of TPI, types of rubber, TPIMooney viscosity, plasticizer type, the amount of plasticizer, carbon black type, the amount ofcarbon black, the vulcanization system, the amount of sulfur and NR/TPI/BR system on theperformance of TPI blends has been studied. Low-temperature performance and dampingproperties of TPI blends has been respectively characterized by Gehman test, low-temperaturecompression set and dynamic mechanical analysis.It is to be found that the blends with TPI Mooney viscosity of50has the best overallperformance. Plasticizer can improve low temperature properties of rubber in varying degrees.Dioctyl sebacate (DOS) has the most obvious effect, while it has the best dampingperformance when the amount comes to15phr. Rubber that filled with N550carbon blackhas excellent physical and mechanical properties and low temperature performance. As thecarbon black particle size increases, the damping effect becomes better. When the amount of carbon black is35phr, the flex fatigue properties is of the best. The low temperatureperformance is the best when the amount of carbon black reaches45phr. The flex fatigueproperties, low temperature performance and damping properties of common sulfurvulcanization system is better than effective curing system and semi-efficient vulcanizationsystem. TPIR have good fatigue, low temperature and damping properties. The lowtemperature performance can be effectively enhanced when incorporated with BR.TPI derivative produced by chlorosulphonylation is studied in the third chapter, and lowtemperature performance and damping properties are also investigated. With increasingdegree of chlorosulphonylation, the crystallinity of TPI reduced. When the amount of SO2Cl2is6parts, the vulcanizates have good mechanical properties and fatigue properties.Meanwhile, the low temperature performance and damping properties are both improvedafter modification.