Labile hyperbranched poly(triazene ester)s – decomposition behavior and their use as porogens in thermally stable matrix polymers

Abstract

Hyperbranched polyesters containing labile triazene units in the main chain have been characterized according to their photochemically and thermally induced decomposition behavior. Irradiation with UV light results in a first order decomposition behavior with half-time of 6 to 48 min depending on the structure of the repeating unit. Thermal decomposition starts at about 160°C, and about 50% mass loss are achieved after 15 min at 250°C. Homogeneous incorporation of these globular, functional polymers in thermostable polymer matrices (polyimides and benzocyclobutane-based polymers) was possible. Smooth films from blends of thermostable matrix and up to 50% hyperbranched polymers could be prepared. The hyperbranched component could be destroyed selectively, and the resulting porous matrix has been studied as insulating material for microelectronic multilayer applications.

Amphiphilic block copolymers containing thermally degradable poly(phthalaldehyde) blocks

“…Block copolymers containing polyaldehyde blocks can be interesting for many different fields of applications. As described for other thermodegradable polymers, the use as porogens in heat‐sensitive matrices34 is an obvious opportunity. Furthermore, as one can easily decompose the poly(aldehyde) block without affecting the second polymer, self‐assembling block copolymers with such depolymerizable blocks could be used as templates for the engineering of nanostructured materials.…”

Hyperbranched polymers—All problems solved after 15 years of research?

“…In general, hb polyesters are discussed and used widely today in different applications such as coatings and resin formulations, as additives for improving the thermal properties and modulus, changing the rheology, and improving the flow, viscosity, and surface properties, and even in sensorics and nanofoam preparation. For the latter applications, specific labile groups have been incorporated into the polyester backbone, such as labile triazene units 169, 170. These allow the hb polyester to degrade in an organic matrix during the solidification of the matrix, leading to an increase in the free volume and thus a lower dielectric constant.…”

Novel Hyperbranched Poly([1,2,3]‐triazole)s Derived from AB2 Monomers by a 1,3‐Dipolar Cycloaddition

“…Experiments in which thermally labile hyperbranched poly(triazene ester)s were used as porogens were successful. [15] This first study proves the potential of the [2 þ 3]-cycloaddition reaction involving alkynes and azides for the preparation of new hyperbranched polymers but also shows the necessity of high control and optimization of the reaction conditions due to the high reactivity of the A and B functions.…”