Preparation and characterization of clay-biopolymer nanocomposites via in situ polymerization

초록

In recent years polymer/layered silicate nanocomposites have attracted great interest, both in industry and in academia, because they often exhibit remarkable improvement in materials properties. The difference in the responses was attributed to the specific polymer-clay interactions. A strong polymerclay interaction enlarged or exfoliated the clay layers, whereas a weak interaction left them intact. Both the molecular level dispersion of the clay layers in the polymer matrix, and the degree of interaction between the polymer matrix and the clay, determines the physical and mechanical properties of the polymer-clay composite. In general, two routes were adopted to improve the interaction between polymer and clay. One is to use proper cationic surfactants to modify the clay by an ion exchange reaction (the presence of a functional group also improved the interaction). The main objective of this experiment is to devise a new and convenient method to introduce additional functional groups to the organoclay. A functionalized organoclay was prepared by reacting (glycidoxypropyl)trimethoxysilane (GPS) with the Si？OH groups of a clay that had already been modified by cationic surfactants, and is referred to herein as twice-functionalized organoclay (TFC). The silane compounds may contain other functional groups, which may interact with the polymer matrix to further improve the interfacial interaction. The clay-polymer hybrid was generated in situ, and the fine morphology and superior mechanical properties were observed experimentally.