Solid State NMR Analysis of Two Grafted Biopolymers

摘要

A potential alternative to achieve smart materials for biomedical applications is the combination of natural and synthetic polymers. In order to understand the structure and properties of two γ-radiation grafted biopolymers, chitosan-g-poly(N-isopropylacrylamide) (CS/PNTPAAm) and cotton-g-2-(dimethylamino) ethyl methacrylate (CG-DMAEMA) were analyzed by solid state nuclear magnetic resonance (SSNMR) 13C-CPMAS at different contact times (t_(CP)). The use of different t_(CP) in this grafted biopolymers showed that chemical shifting, broadening, size and symmetry of the some signals, gives important information for structure elucidation and molecular mobility. SSNMR spectra indicate changes in the local order structure, CG suffered less modifications when it is grafted than CS. CG-g-DMAEMA spectrum is very similar to CG spectrum, in contrast with spectrum of CS-g-NIPAAm, is very different than CS. Spectra of swelling polymers in water showed more structural information about secondary structure.