Preparation and characteriszation of nanocellular poly(phenylquinoxaline)foams. A new approach to nanoporous high-performance polymers

• Published in: Macromolecules Vol. 40; pp. 2070 - 2078
• Main Authors: Merlet, Samuel, Marestin, Catherine, Schiets, Frédéric, Romeyer, Olivier, Mercier, Régis
• Format: Journal Article
• Language: English
• Published: American Chemical Society 2007
• Subjects: Chemical Sciences; Polymers; polyphenylquinoxaline foam thermal treatment porous structure; Polyquinoxalines; Polymer; Polysulfones
• ISSN: 0024-9297; 1520-5835

This work deals with a new strategy for the elaboration of macro- to nanoporous materials. The adopted scheme involves the in-situ generation of foaming agents (CO2 and isobutene) during the thermal treatment of a poly(phenylquinoxaline) (PPQ) film bearing thermolabile (tert-butyloxycarbonyl, i.e., Boc) groups (PPQ-Boc). For this purpose, a bis-diketone monomer having phenolic groups has been first synthesized and polymd. with a bis-diamine monomer. The resulting PPQ was post-modified by introducing Boc groups. After a kinetic and mechanistic study of the Boc thermal decompn. reaction, the influence of different exptl. parameters on the final porosity formation has been investigated, such as the foaming temp. which is a key parameter. The porous materials obtained were characterized by different techniques (d., SEM, TEM) in order to det. the cell d. as well as the size and morphol. of the porous structure. Depending on the thermal treatment conditions, our strategy enables to obtain a wide range of porous materials, from nanoporous (10 nm, 1016 cells/cm3) to macroporous (200-700 nm, 1012 cells/cm3).