title: Intrinsically microporous polyesters from betulin - toward renewable materials for gas separation made from birch bark.
abstract: Betulin, an abundant triterpene, can be extracted from birch bark and can be used as a renewable monomer in the synthesis of microporous polyesters. Cross-linked networks and hyperbranched polymers are accessible by an A(2)  + B(3)  reaction, with betulin being the A(2)  monomer and B(3)  being a trifunctional acid chloride. Reaction of betulin with a diacid dichloride results in linear, soluble polyesters. The present communication proves that the polyreaction follows the classic schemes of polycondensation reactions. The resulting polymers are analyzed with regard to their micro-porosity by gas sorption, NMR spectroscopy, and X-ray scattering methods. The polymers feature intrinsic microporosity, having ultrasmall pores, which makes them candidates for gas separation membranes, e.g., for the separation of CO(2)  from N(2) .
authors.affiliation: Department of Colloid Chemistry, Max Planck, Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany.
authors.forename: Jekaterina
authors.initials: J
authors.lastname: Jeromenok
authors.forename: Winfried
authors.initials: W
authors.lastname: Böhlmann
authors.forename: Markus
authors.initials: M
authors.lastname: Antonietti
authors.forename: Jens
authors.initials: J
authors.lastname: Weber
mesh_terms: D000327:Adsorption; D029662:Betula / Q000737:chemistry*; D005740:Gases / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D016062:Porosity; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification; D000094062:Betulinic Acid
chemical_list: D005740:Gases; D010936:Plant Extracts; D011091:Polyesters; D014315:Triterpenes; C002503:betulin; D000094062:Betulinic Acid