硝化纤维素溶液冰冻过程中的折光指数增量

用定量体积排斥色谱（ＳＥＣ）的方法，以示差折光检测器的响应为基础，测定了硝化纤维素溶液冰冻及其加热以后的折光指数增量。结果表明：冰冻后，由于分子链发生链内凝聚（缠结），硝化纤维素分子链周围溶剂化溶剂分子数减少，使硝化纤维素溶液的示差折光指数增量增加。加热后，由于硝化纤维素分子链获得能量，链内缠结点解开，溶剂化溶剂分子数增加，造成硝化纤维素溶液的折光指数增量降低。由此建立了以折光指数增量为基础，估算硝化纤维素分子在溶液中完全伸展时每个链段上的溶剂化溶剂分子数的理论公式，并且估算出常温下每个硝化纤维素链段就吸附有１３个溶剂化溶剂分子，这对建立硝化纤维素这类半刚性高分子链凝聚过程和凝聚态结构的物理图像具有重要意义。

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.