title: Thermal decomposition of fungal poly(beta,L-malic acid) and Poly(beta,L-malate)s.
abstract: The thermal decomposition of poly(beta,l-malic acid), poly(alpha-methyl beta,l-malate), and ionic complexes of the polyacid with alkyltrimethylammonium salts was studied by TGA, GPC, and FTIR and NMR spectroscopy. It was found that poly(beta,l-malic acid) depolymerized above 200 degrees C by an unzipping mechanism with generation of fumaric acid which is then partially converted in a mixture of maleic acid and anhydride. On the contrary, random scission of the main chain was found to happen in the thermal decomposition of poly(alpha-methyl beta,l-malate). On the other hand, ionic poly(beta,l-malate)s degraded through a well defined three-stage process, the first one being depolymerization of the poly(malate) main chain along with decomposition of the ionic complex. Decomposition of the previously generated alkyltrimethylammonium salts followed by unspecific cracking of the resulting nitrogenated compounds happened at higher temperatures. Mechanisms partially explaining the decomposition processes of the three studied systems were proposed according to collected data.
authors.affiliation: Departament d'Enginyeria Química, Universitat Politècnica de Catalunya, ETSEIB, Diagonal 647, 08028 Barcelona, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Portilla-Arias
authors.forename: Montserrat
authors.initials: M
authors.lastname: García-Alvarez
authors.forename: Antxon
authors.initials: A
authors.lastname: Martínez de Ilarduya
authors.forename: E
authors.initials: E
authors.lastname: Holler
authors.forename: Sebastian
authors.initials: S
authors.lastname: Muñoz-Guerra
mesh_terms: D002850:Chromatography, Gel; D005658:Fungi / Q000737:chemistry*; D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D008293:Malates / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D008293:Malates; D011108:Polymers; C074640:poly(malate)