Chain microstructure and conformation of partially quaternized poly(dimethylaminoethyl methacrylate)

Abstract

¹H-NMR spectroscopy was used to establish the chain microstructure and conformation produced by the quaternization reaction of syndiotactic poly[2-(dimethylamino)ethyl methacrylate], a polymer with tertiary amino groups in the side chains. A chain microstructure with mini blocks of modified units was found by analyzing the N⁺CH₃ signal that was proved to be split in accordance with the composition triads. The macromolecular backbone changes its form by quaternization, from a close to an expanded coil, was confirmed by light scattering measurements and NOE spectra modifications. The two linked processes, the block formation and chain expansion can be the key in developing a reaction mechanism explaining both positive and negative deviations from a second-order kinetic model.

Keywords:

• NMR
• chain microstructure
• chain conformation
• quaternized PDMAEMA

Disclosure of potential conflict of interest

There is no potential conflict of interest concerning this work.

Additional information

Funding

Financial support from the European Social Fund for Regional Development, Competitiveness Operational Programme Axis 1 - Project “Petru Poni Institute of Macromolecular Chemistry - Interdisciplinary Pol for Smart Specialization through Research and Innovation and Technology Transfer in Bio (nano)polymeric Materials and (Eco) Technology”, InoMatPol (ID P_36_570, Contract 142/10.10.2016, cod MySMIS:107464), is greatfully acknowledged.