Proton motion of poly(gamma-benzyl L-glutamate) in benzyl alcohol during gelation as measured by quasielastic neutron scattering

Quasielastic neutron scattering has been used to study the motion of protons in two solutions of poly(gamma-benzyl L-glutamate) (PBLG) and deuterated benzyl alcohol (DBA) as they are brought from the high temperature (cholesteric and isotropic) phase towards the gel. Quasielastic neutron scattering results demonstrate that, in both the isotropic and cholesteric phases, the local rotational dynamics of the polymer are continuous in the high temperature phases, but become more constrained as the system approaches and enters the gel phase. The results also show that the energetics of the rotational motion of the protons below the gelation threshold are independent of the initial phase and the protons are not rendered immobile in the gel phase. (C) 1996 John Wiley & Sons, Inc.