Study On Synthesis And Application Of Modified Polynorbornene

Olefin metathesis reaction refers to a type of reaction in which carbon-carbon double bonds are cut and recombined under the action of metal carbene catalysts between unsaturated compounds.It is an effective means to efficiently construct complex molecular structures.Used in the fields of organic chemistry and polymer chemistry.Based on the principle of olefin metathesis,this paper studies the synthesis and structural modification of polynorbornene(PNB),and explores the application of PNB in the modification of hydrogenated nitrile rubber(HNBR).The main work of the thesis is as follows:(1)The PNB with controllable molecular weight was successfully prepared by ring-opening metathesis polymerization(ROMP).The effects of catalyst type,solvent type,reaction temperature,reaction time and catalyst amount on the structure and molecular weight of PNB molecular chain were studied,and the results were obtained in chlorobenzene solvent,the reaction temperature is 30℃,the reaction time is 2 h,and the molecular weight can be adjusted by changing the amount of catalyst;(2)A new type of PNB-HNBR copolymer was synthesized by cross metathesis reaction,and the structure was characterized by ’H-NMR,13C-NMR,GPC and DSC.The reaction mechanism was discussed and analyzed,and it was found that the degree of hydrogenation of HNBR has an important influence on the molecular chain structure of the copolymer.When the degree of hydrogenation is 92%,a block copolymer is formed,and when the degree of hydrogenation is 70%,a random copolymer is formed;(3)PNB/HNBR blend vulcanizates and PNB-HNBR copolymer vulcanizates were prepared to study the properties of vulcanizates.The results showed that the low-temperature resistance of the two vulcanizates was improved after being filled with naphthenic oil,and the mechanical properties of the copolymer vulcanizate were better than that of the blended vulcanizate.The effect of the amount of PNB in the copolymer on the performance of the copolymerized vulcanizate was further studied.The results show that when the amount of PNB is 60 phr,the copolymer vulcanizate has better low temperature resistance,mechanical properties and damping properties.