Postpolymerization modification of polynorbornene side chains via tetramethyl guanidine promoted esterification

We demonstrate that polynorbornene containing primary activated bromide moieties is a novel chemically modifiable platform for postpolymerization modification. Polymer P0 was synthesized via ring-opening metathesis polymerization of monomer 1 with the assistance of Grubbs third generation (G-III) catalyst. Subsequently, nucleophilic substitution was conducted by mixing P0 with n -caproic acid, sorbic acid, m -toluic acid or 4-nitrobenzoic acid in the presence of 1,1,3,3-tetramethylguanidine (TMG) under mild and stoichiometric condition to generate functionalized polymers P1–P4 . NMR results approved full conversion of the reactive sites and exemplified the “click” nature of TMG promoted esterification. Thermal stability and glass transition behaviors of all the polymer samples were investigated by thermal gravimetric analysis and differential scanning calorimetry. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54 , 3733–3740