β-成核作用硅灰石及其填充β-PP制备.doc

-成核作用硅灰石及其填充-PP制备中山大学化学与化学工程学院材料科学研究所，教育部聚合物基复合材料及功能材料重点实验室, 广州510275硅灰石填充聚丙烯（PP）已有大量研究1-4。硅灰石对PP结晶具有-成核作用，主要形成-晶。虽然提高PP刚性和强度，但导致PP冲击强度更低。添加弹性体可改善其韧性，但对刚性有负面影响5-7。-PP冲击强度和热变形温度高于-PP，但填充-PP研究不多，归结于填料表面-成核作用的影响，采用添加-成核剂的方法难于制备填充-PP。本文根据碳酸钙负载-成核剂的制备原理8，实现了硅灰石表面成核机理的转变，制得具有-成核作用的-硅灰石和高含量硅灰石填充-PP。从硅灰石填充PP的DSC（Figure 1）可见，PP结晶温度随硅灰石用量增加而逐渐提高，加入40%硅灰石，PP结晶温度从113.2提高到121.2，表明硅灰石对PP结晶具有明显的异相成核作用，但PP主要形成-晶。 Figure 1 DSC crystallization (a) and melting (b) curves of wollastonite filled PP -硅灰石填充PP的结晶温度也随硅灰石用量增加而逐渐提高，表明-硅灰石对PP结晶也具有明显的异相成核作用，但PP主要形成-晶，见Figure 2，也为XRD证实（Figure 3）。Figure 2 DSC crystallization (a) and melting (b) curves of wollastonite filled -PP Figure 3 XRD of wollastonite filled -PP-硅灰石的-成核作用取决于制备硅灰石表面负载-成核剂的量。从Figure 4 和5可见，硅灰石表面负载-成核剂的量多（W100到W1000）时，对PP结晶与熔融行为影响不大，主要形成-晶。但随着硅灰石表面负载-成核剂量减少，-晶熔融峰强度降低，-晶熔融峰强度提高，表明-成核作用减弱。Figure 4 DSC crystallization (a) and melting (b) curves of wollastonite filled -PP Figure 5 XRD of wollastonite filled -PP以上研究表明，将硅灰石表面-成核作用转变为-成核作用，采用-硅灰石很容易制得高-晶含量的硅灰石填充-PP复合材料。参考文献：1 Yang M, Adv Mater Res, 2010, 92: 283.2 Luyt AS, Dramicanin MD, Antic Z, Djokovic V, Polym Testing, 2009, 28(3): 348.3 Meng MR, Dou Q, Mater Sci Eng A, 2008, 492(1-2): 177.4 Himani J, Purnima J, Mater Sci Eng A, 2010, 527(7-8): 1946. 5 Balkan O, Ezdesir A, Demirer H, Polym Compos, 2010, 31(7): 1265.6 Singh UP, Biswas BK, Ray BC, Mater Sci Eng A, 2009, 501(1-2): 94.7 vab I, Musil V, Pustak A, mit I, Polym Compos, 2009, 30(7): 1007.8 Zhao S, Cai Z, Xin Z, Polymer 2008, 49(11): 2745.Preparation of Wollastonite with -Nucleation and Wollastonite Filled -PolypropyleneMaterials Science Institute, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Key Laboratory of Polymeric Composites and Functional Materials, Guangzhou, 510275Abstract: In order to prepare wollastonite filled -PP composites, wollastonite with -nucleation and wollastonite filled -PP composites were prepared. The crystallization behavior and melting characteristics of wollastonite filled PP and wollastonite filled -PP were investigated with differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WXRD). The results indicated that the crystallization behavior of PP in wollastonite filled PP and wollastonite filled -PP increased with the increasing of wollastonite. However, wollastonite filled PP formed -form and wollastonite filled -PP formed -form, which proved that the nucleation mechanism had changed from -nucleation to -nucleation. The wollastonite with -nucleation (-wollastonite) was obtained and wollastonite filled -PP composites with high content of