利用DSC测定复合材料的非等温结晶动力学特征参数

测试了MRP A66,MRPET和MRPP三种复合材料在六种降温速率下的非等温结晶DSC曲线.在A.Jeziorny的基础上提出了测定高聚物非等温结晶动力学特征参数的新的数据处理方法。首次报导了这三种复合材料的非等温结晶动力学特征参数。结果表明,非等温动力学结晶能力G_c与高聚物的降温速率无关。当降温速率大等于8k/分时,非等温结晶速率常数Z_c与降温速率无关,但当降温速率小等于5k/分时,Z_c值随降温速率变小而迅速减小,此时Jeziorny理论已不适用.结果还表明,随着降温速率变大,MRPET的Avrami指数增大,而MRPA66和MRPP的Avrami指数却变小。

PARAMETERS CHARACTERIZING THE KINETICS OF THE NON-ISOTHERMAL CRYSTALLIZATION OF COMPOSITE MATERIALS DETERMINED BY DSC

Difforential Scannling Calorimetry (DSC) curves of mica-reinforced poly- amide 66 (MRPA66), mica-reinforced polythylene terephthalate (MRPET) and mica-reinforced polypropylene (MRPP) in the six cooling rates (15k/min., 10k/ min., 8k/min., 5k/min., 2k/min. and 1k/min.) are determined. A new data processing mothod of determining the parameters to charaeterize the kinetics of non-isothermal crystallization of polymers on the basis of Jeziorny equation is presented. These parameters to characterize thenon-isothermal crystallization of three composite materials are listed. The results show that the values of the kinetic crystallizability G, of three materials are not dependent on the cooling rate of polymers. The values of the non-isothermal crystallization rate Z. are constant when the cooling rate is reater than 8k/min., but Z. decrease quickly with decreasing in cooling rates when the rates are less than or equal to 5k/min., in which case Jeziorny theory is not valid. The values of the Avrami exponent are determined, based on the data obtained from DSC curves. It is found that the values of the Avrami exponent of MRPET increase with increasing of cooling rates while those of MRPA66 and MRPP decrease.