Refractive index increase of nitrocellulose solution after being freezed

The refractive index increasements of nitrocellulose solution after being freezed and heated were measured by means of the response of differential refractive detector of size exclusion chromatography. The results show that the refractive index increasement of nitrocellulose solution will increase after being freezed and decrease after being heated. The reason that the refractive index increasement of nitrocellulose solution increases is that the interchain entanglement formats and the number of solvated solvent decrease when the solution is freezed. The reason that the refractive index increasement of nitrocellulose solution decreases is that the interchain entanglement vanishes and the number of solvated solvent increase when the solution is heated. The method to evaluate the number of solvated solvent on the nitrocellulose molecule chain in solution and the theory formula were given at the same time. The number of the solvated solvent molecule joined with a monomeric unit is 13 when the nitrocellulose molecule extends fully in solution. It is very important for the half-rigid nitrocellulose chain to set up the physical scheme of condensed process and condensed state structure.