Novel multifunctional polymeric materials with predominant cis microstructures derived from alpha-norbornenyl macromonomer and stable macroinitiator via ring-opening metathesis polymerization and atom transfer radical polymerization

摘要

Novel star-like polymeric materials with high cis content could be obtained by using alpha-norbornenyl macromonomers and highly stable macroinitiators derived from an active norbornene derivative [5-(2-bromo-2-methylpropionylaminomethyl)bicyclo[2.2.11hept-2-ene (NBBrMPAM)], which was synthesized by the reaction of norbornene methylene amine and 2-bromo-2-methylpropionyl bromide. The alpha-norbornenyl macromonomer (NBPMMA), which is polymethyl methacrylate containing norbornenyl end group, was prepared by atom transfer radical polymerization (ATRP) using NBBrMPAM as an initiator. Star-like polynorbornene with high cis microstructure (cis/trans = 72/28) was obtained directly by ring-opening metathesis polymerization of NBPMMA macromonorner having number molecular weight ((Mn) over bar) as low as 6.39 x 10(3). Random ring-opening metathesis copolymerization of NBPMMA and norbornene derivative containing carbazole group (NBCbz) was carried out at 25 degrees C by using Ru catalyst [(CY3P)(2)Cl2Ru = CHPh, Cy = cyclohexyl, Ph = phenyl]. High cis (cis/trans = 63/37) organo-soluble star-like random poly(NBPMAIA-co-NBCbz) was successfully obtained with high number-average molecular weight ((Mn) over bar) of 4.76 x 10(4) and molecular weight distribution polydispersity index of 1.78. Organo-soluble comb-shaped copolymers with MMA could be successfully obtained using ATRP macroinitiator [poly(HNBBrMPAM)l in diluted macroinitiator solution with a concentration less than 3.64 x 10(-2) mol.L-1. This is the first ever attempt to prepare novel star-like organo-soluble polymeric materials with high cis microstructure via the combination of ring-opening metathesis polymerization and ATRR Multimodification could be considered to be carried out by using the functional bromo group at the end of side chains.