LAUSR

ROMP is an effective method for preparing functional polymers due to its having characteristics of “living” polymerization and rapid development of catalysts. In the present work, poly(norbornene-methylamine), a mimic of chitosan, was synthesized via ROMP reaction. The amino-protected product, 5-norbornene-2-(N-methyl)-phthalimide, was prepared by a reaction of 5-norbornene-2-methylamine with phthalic anhydride, which was then subjected to the ROMP reaction in the presence of Hoveyda-Grubbs 2nd catalyst to afford poly(norbornene-(N-methyl)-phthalimide). The target product, poly(norbornene-methylamine), was obtained by deprotection reaction of poly(norbornene-(N-methyl)-phthalimide). The products in each step were characterized by FTIR and 1H-NMR, and their thermal stabilities were determined by TG analysis. The effects of molar ratio between monomer ([M]/[I]) and catalyst on the average relative molecular weight (Mn¯) and molecular weight distribution of the produced polymer products were determined by gel permeation chromatography (GPC). It was found that the Mn¯ of poly(norbornene-(N-methyl)-phthalimide) was controllable and exhibited a narrow polydispersity index (PDI) (~1.10). The synthesis condition of 5-norbornene-2-(N-methyl)-phthalimide was optimized by determining the yields at different reaction temperatures and reaction times. The highest yield was obtained at a reaction temperature of 130 °C and a reaction time of 20 min. Our work provides a new strategy to synthesize polymers with controllable structures and free –NH2 groups via ROMP.