Structure–property relationship in chitosan‐based biopolymer/montmorillonite nanocomposites

Three kinds of chitosan-based biopolymer/montmorillonite (MMT) nanocomposites have been prepared by an exfoliation–adsorption method. The structure of MMT is tailored by the functional groups of the polymer matrix. Chitosan/MMT nanocomposites form intercalated-and-flocculated structures, whereas with the introduction of carboxymethyl into chitosan, N,O-carboxymethyl chitosan/MMT nanocomposites form even stronger flocculated structures. On the other hand, direct quaternization of the amino group of chitosan to form N,N,N-trimethyl chitosan chloride/MMT nanocomposites gives a nearly exfoliated structure. The nanodispersion of MMT in the biopolymer matrices affects the thermal degradation mechanism in different ways corresponding to the different kinds of functional groups that are introduced into the chitosan matrix.