Synthesis of poly(butylene terephthalate) nanocomposites using anionic clays

The synthesis of poly(butylene terephthalate) (PBT) nanocomposites by in situ polymerisation method using an organo-modified layered doubled hydroxide is described. 4-sulfobenzoic acid potassium salt, sodium dodecyl sulphate and dimethyl 5-sulfo isophtalate sodium salt were used as intercalating compounds to improve clay exfoliation. The thermal and dynamic mechanical properties of the nanocomposites prepared were investigated and compared to those of montmorillonite-type nanocomposites prepared by similar synthetic route. The nanocomposites obtained, independent of the degree of exfoliation, showed better dynamic mechanical properties respect to PBT homopolymer while improvements in thermal stability were achieved when dimethyl 5-sulfo isophtalate was used as intercalating agent, highlighting the importance of the interactions of ionic groups covalently linked to the polymer with the charged clay platelets.