Preparation of Highly Impermeable Hyperbranched Polymer Thin-Film Coatings Using Dendrimers First as Building Blocks and Then as in Situ Thermosetting Agents

Abstract

This report describes the synthesis, characterization, and passivation properties of durable, polyfunctional, and highly cross-linked hyperbranched dendrimer/polyanhydride composite thin films. Such films are prepared from either amine- or hydroxyl-terminated poly(amidoamine) (PAMAM) dendrimers or amine-terminated poly(iminopropane-1,3-diyl) dendrimers (64-Cascade), and the copolymer poly(maleic anhydride)-c-poly(methyl vinyl ether), Gantrez. The dendrimers serve two roles in these composite films. First, they serve as building blocks, which permeate into and covalently cross-link a chemisorbed Gantrez copolymer. Then, in a separate thermal processing step, the dendrimers form highly impermeable monolithic films. In the case of amine-terminated dendrimers, the amic acid groups that attach the dendrimers to the original Gantrez network polymer form imides. Additionally, internal β-amino groups within both the amine- and hydroxyl-terminated PAMAM dendrimers undergo retro-Michael reactions. Subsequently, a c...