Structure and properties of a new polymer nanocomposite based on a poly(hydroxy ether of bisphenol A) matrix

Poly(hydroxy ether of bisphenol A) (Ph) based polymer nanocomposites (PN) reinforced with a layered clay (montmorillonite) with three organic modifications that differed in polarity and molecular weight were prepared by melt intercalation. The best dispersion occurred in the PN where the interactions between the functional groups of the polymer matrix and those of the organic substitution of the clay appeared to be the highest, and was improved upon modification of the processing procedure. The modulus increases (62% upon 4% MMT addition) are an indirect but quantitative measurement of the attained dispersion level. The impact strength and ductility also increased. This was attributed to the combined effects of stacks presence and an additional orientation of the matrix, and differs from the decline of the fracture properties that is usually observed in other PNs upon stiffening. The organoclay with the highest Ph intercalation, measured by the increase in the gallery height, led to the lowest clay dispersion, indicating that a high degree of intercalation is not a requisite for dispersion in these PNs. A lower molecular weight of the surfactant led to higher Ph intercalation but did not influence dispersion. Finally, intercalation was not influenced by a similarity in polarity (higher chemical interaction) between polymer and surfactant, but this similarity in polarity did influence dispersion indicating that the structural parameters leading to wide intercalation and wide exfoliation are not the same in the Ph based nanocomposites.