نوع مقاله : پژوهشی
نویسندگان
1 تهران، دانشگاه تهران، دانشکده علوم و فنون نوین، کدپستی ۱۳۷۴-۱۴۳۹۵
2 تهران، دانشگاه صنعتی شریف، دانشکده مهندسی و علم مواد، صندوق پستی ۹۴۶۶-۱۱۳۶۵
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The effect of organically modified clay on the structure and deformation mechanism of polymeric matrices was investigated. For this purpose, the role of organoclay in deformation control of polymeric matrices, with different deformation mechanisms, has been studied methodically in order to determine a relationship between the structure and deformation mechanisms. In this respect polypropylene and polystyrene composites systems were designed using montmorillonite through melt intercalation technique using a twin, co-rotating extruder with starve feeding system. Also an epoxy was employed to design a nanocomposite system prepared by in-situ polymerization technique. The structure and deformation mechanism of nanocomposites were investigated using appropriate techniques. X-Ray diffraction and transmission electron microscopy were used to explore the structure of various systems while, the reflection and transmission optical microscopy were used in order to study their corresponding deformation mechanisms. The bulk polymer was also studied for its deformation mechanism by reflection optical microscopy and the notch tip of the samples were examined by transmission optical microscopy. The results of experiments showed that organoclays acted as initiator sites for shear yielding mechanism as the dominant deformation mechanism in epoxies. It may be noted that, these particles may act as initiator sites for crazing, the dominant deformation mechanism of polystyrene, and alter the mechanism from local to massive. In polypropylene systems, which may exhibit both shear yielding and crazing organoclays can facilitate or postpone both mechanisms in different conditions, related to PP morphology and other conditions.
کلیدواژهها [English]
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