Solid-state studies of the crystalline/amorphous character in linear Poly(ethylenimine hydrochloride) (PEI-HCl) polymers and their copper complexes

JUAN MANUEL LÁZARO MARTÍNEZ; ENRIQUE RODRÍGUEZ-CASTELLÓN; DANIEL VEGA; GUSTAVO A. MONTI; ANA KARINA CHATTAH

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 vol. 48 p. 1115 - 1115

inear poly(ethylenimine hydrochloride) (PEI-HCl) polymers with different molecular weights (22, 87, and 217 kDa) and their copper complexes (Cu−PEI) were studied with particular attention to the crystalline/amorphous character of the polymeric chains in lyophilized and crystallized samples by using 1D and 2D solid-state nuclear magnetic resonance, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. Different 13C{1H} cross-polarization and magic angle spinning experiments using delayed contact time, 1H dipolar filter and 1H spin-lock filter were crucial to determine the different mobility domains in the crystallized and lyophilized samples of PEI-HCl and Cu−PEI. 13C direct polarization experiments allowed the quantification of the crystalline/amorphous segments in each sample. The lyophilization process produced an increase in the amorphous fraction, even when some ordered domains were present, whereas the coordination of copper/sulfate ions produced a sign