MgZnAl-CO_3制备、表征及其对PVC热稳定性的协同效应

用成核-晶化隔离法制备了层状MgZnAl-CO3纳米晶,借助于TG-DSC、IR、XRD、SEM和热老化箱对其结构、形貌及其与Ca（st）2/Zn（st）2复配对PVC热稳定性的协同效应进行了系统研究。结果表明,层板上半径为0.065nmMg2＋被半径为0.074nmZn2＋同晶取代后,Mg0.51Zn0.167Al0.323-CO3较Mg0.677Al0.323-CO3层间结晶水、层板羟基和层间阴离子CO32-脱除温度分别下降14.0℃和8.4℃,层板OH伸缩振动、层间结晶水弯曲振动和层间CO32-反对称振动吸收峰向高波数方向移动,（003）晶面间距从0.7455nm增加到0.7508nm、a（或b）和c轴长度分别从0.3038nm和2.2365nm增加到0.3044nm和2.2524nm;由于一定量的Mg0.51Zn0.167Al0.323-CO3与Ca（st）2/Zn（st）2的协同作用,PVC的初期着色和热稳定时间分别为250min和275min。

Preparation and characteristic of MgZnAl-CO_3 and the synergetic effect on heat stability of PVC resin

The layered MgZnAl-CO3 nanocrystal were synthesized by Nucleation/Crystallization Separation.The structure、morphology and synergetic effect on heat stability of PVC with Ca（st）2/Zn（st）2 mixtures were studied by TG-DSC、IR、XRD、SEM and thermal ageing tests oven.The result shows that compared to Mg0.677Al0.323-CO3,after Mg2＋（0.065nm） was replaced by Zn2＋（0.074nm）,the desorption temperature of interlayer water、layer hydroxyl group and interlayer CO32-in Mg0.51Zn0.167Al0.323-CO3 decreased 14.0℃ and 8.4℃,respectively.The absoption peak moved to high wave number,including the stretching vibration of layer hydroxyl group、the bending vibration of layer hydroxyl group and the antisymmetric vibration of interlayer CO32-.The interplanar spacing of（003）increased from 0.7455nm to 0.7508nm,the length of a（or b）and c axises increased from 0.3038nm to 0.3044nm and from 2.2365nm to 2.2524nm,respectively;because of the synergetic effect on a certain amount of Mg0.51Zn0.167Al0.323-CO3 and Ca（st）2/Zn（st）2,the time of early coloration and heat stability of PVC are 250min and 275min,respectively.