Carniato Fabio, Fina Alberto, Tabuani Daniela, Boccaleri Enrico
Dipartimento di Scienze e Tecnologie Avanzate and Nano-SISTEMI Interdisciplinary Centre, Università del Piemonte Orientale 'A. Avogadro', Via Bellini 25G, I-15100 Alessandria, Italy.
Nanotechnology. 2008 Nov 26;19(47):475701. doi: 10.1088/0957-4484/19/47/475701. Epub 2008 Oct 30.
This paper deals with the preparation and characterization of isotactic polypropylene (PP) containing different metal-polyhedral oligomeric silsesquioxanes (M-POSS). Two M-POSS, Ti(IV)- and Al(III)-isobutyl-POSS, defined by a monomeric structure, were selected for dispersion, and particular attention was paid to the assessment of the morphology, crystallization process and thermal behavior of M-POSS/PP composites, using SEM and TEM microscopy, x-ray diffraction (XRD), FTIR and Raman spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and gas chromatography/mass spectrometry. The study of M-POSS/PP thermal degradation showed that Ti-POSS and Al-POSS induce different effects on the thermoxidative behavior of the polypropylene matrix, showing a clear specificity of the metal center on the PP degradation pathway. In particular, Ti-POSS showed a significant stabilization of PP when heating under air, whereas limited effects were observed with Al-POSS. Moreover, Ti-POSS was also found to affect PP crystallization, driving the crystallization process along specific crystallographic directions.
本文研究了含有不同金属-多面体低聚倍半硅氧烷（M-POSS）的等规聚丙烯（PP）的制备与表征。选择了两种由单体结构定义的M-POSS，即Ti(IV)-和Al(III)-异丁基-POSS进行分散，并特别关注使用扫描电子显微镜（SEM）和透射电子显微镜（TEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和拉曼光谱、差示扫描量热法（DSC）、热重分析（TGA）以及气相色谱/质谱法对M-POSS/PP复合材料的形态、结晶过程和热行为进行评估。对M-POSS/PP热降解的研究表明，Ti-POSS和Al-POSS对聚丙烯基体的热氧化行为产生不同影响，显示出金属中心在PP降解途径上具有明显的特异性。特别是，Ti-POSS在空气气氛下加热时对PP表现出显著的稳定作用，而Al-POSS的影响有限。此外，还发现Ti-POSS会影响PP的结晶，促使结晶过程沿着特定的结晶学方向进行。
