醋酸纤维素／聚乙烯基吡咯烷酮共混体系的相容性研究（Ⅰ）

MISCIBILITY INVESTIGATION OF CELLULOSE DIACETATE WITH POLY (VINYL PYRROLIDONE)

用ＤＳＣ，ＤＭＴＡ研究了醋酸纤维素（ＣＤＡ），聚乙烯基吮咯烷酮（ＰＶＰ）及ＣＤＡ／ＰＶＰ共混体系的玻璃化转变行为．用精密量热法测定了该体系的混合热焓．结果表明：共混体系只存在一个玻璃化转变温度（Ｔｇ），其值随共混组成的变化而改变；共混体系的混合热焓为负值，其绝对值随组成中ＰＶＰ含量的增加而减少．力学性能研究表明，共混体系具有协同效应．上述试验结果证明，ＣＤＡ和ＰＶＰ是一对相容性高聚物．

he phase behaviour and glass transition temperateal of cellulose diacetate (CDA)/poly (vinyl pyrrolidone)(PVP ) blends were extensively inveshgated by OM,DSC and DMTA. Transparency films were observed in the composition range of CDANVP= 100/0 to 50/50 (by wt.) No any phase separation was found up to the degradation temperature of blending components. A single and composition dependence Tg was obtained in all the range of blending compositions. And a synergism for mechanical properties of CDA/PVP blends was also found. The mixing enthalpy of this blending system was determined and calculated by using the calorimetry and the Hess law. Negative and composition dependent mixing enthalpy was found. All the above experimental results strongly suggest that CDA and PVP are miscible.