The Preparation And Property Of Functional Eucommiz Ulmoides Gum Elastomer

Eucommia ulmoides resources in China account for 95%of the world,and the planting range is wide.Eucommia ulmoides gum,a natural macromolecule,can be extracted from the leaves,barks and seeds of Eucommia ulmoides.The molecular structure of Eucommia ulmoides gum is trans-poly(1,4,isoprene),which is isomeric with natural rubber.Eucommia ulmoides gum has a high degree of regularity and crystallinity due to its high trans-structure.It is in plastic state at room temperature.This molecular structure not only makes it difficult to process and mix,but also limits its application.In this paper,the carbon-carbon double bonds in the molecular chain of Eucommia ulmoides gum were destroyed by thiol-ene click chemistry,the trans-structure was changed,the crystalline structure was destroyed,and the functional elastomer of Eucommia ulmoides elastomer was prepared.1.Eucommia ulmoides gum-mercaptopropionic acid(EUG-3MA),Eucommia ulmoides gum-mercaptoacetic acid methyl ester(EUG-MT),Eucommia ulmoides gum-dodecyl mercaptan(EUG-DM)elastomers were prepared by the method of thiol-ene click chemistry.The effects of solvent type,glue concentration,sulfhydryl compound dosage,carbon chain length of sulfhydryl compound and polarity of sulfhydryl compound on the grafting efficiency and yield of functional Eucommia ulmoides elastomer were studied.The crystallization properties and glass transition temperatures of EUG-3MA,EUG-MT and EUG-DM elastomers with different grafting rates were studied.Through percolation theory,the rubber-plastic transition points of EUG-3MA,EUG-MT and EUG-DM elastomers were found to be 17.4%,21.3%and 8.1%respectively.2.EUG-ET-25.3%,EUG-BT-24.8%and EUG-DM-10.2%elastomer grafted with ethyl mercaptoacetate,butyl mercaptoacetate and dodecamercaptan were selected for processing,mixing and vulcanization.The vulcanization properties,crosslinking density,carbon black interfacial compatibility,mechanical properties,damping properties and oil resistance of Eucommia ulmoides elastomer,natural rubber and functional elastomer vulcanizates were compared.The results showed that the mechanical properties of functional Eucommia ulmoides elastomer prepared by grafting reaction decreased compared with Eucommia ulmoides elastomer,shortened the curing time,improved the interfacial compatibility of carbon black in vulcanizate,and improved the damping property and oil resistance.Among them,EUG-BT-24.8%elastomer tan?max=1.15,tan8>0.3 temperature range is 34.49?,and oil-resistant functional Eucommia ulmoides elastomer with wide temperature range and high damping has been successfully prepared.