Research progress on preparation technology of norbornene
Cyclic olefin copolymers are a class of high-performance thermoplastic engineering plastics.The preparation technology of monomer norbornene is complex and poses engineering safety challenges,leading to a long-term monopoly by a few enterprises and exorbitant prices.Reports on norbornene synthesis are mostly found in patents with spanning various periods and lacking systematic reviews.This review first summarized the cracking process of dicyclopentadiene for the preparation of cyclopentadiene and compared the liquid-phase with gas-phase methods.Their differences in temperature,residence time,equipment,diluents and inhibitors were analyzed,and the advantages and disadvantages of both methods were discussed.Subsequently,the characteristics of norbornene preparation through addition reactions using liquid-phase,gas-phase and supercritical methods were reviewed.The distinctions and pros and cons of different preparation methods in terms of temperature,pressure,equipment,diluents and other aspects were analyzed,providing valuable reference and guidance for the design and optimization of norbornene preparation processes.Finally,the preparation process of polycyclic norbornene derivatives was introduced.