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Chemoenzymatic synthesis of poly(phenylene disulfides) with insulating properties and resistant to high temperatures
Author(s) -
Sierra Estefanía,
MirandaMolina Alfonso,
Castillo Edmundo,
Hu Hailin,
Ayala Marcela
Publication year - 2017
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.5290
Subject(s) - solvent , polymerization , polymer , phenylene , monomer , catalysis , acetonitrile , thermal stability , chemistry , substrate (aquarium) , materials science , polymer chemistry , chemical engineering , organic chemistry , oceanography , engineering , geology
BACKGROUND Cyclic aromatic disulfides ( CAD ) can be used as cross‐linking agents or precursors for the synthesis of high temperature resistant polymers such as poly(phenylene disulfides) ( PPD ). Chemical synthesis of CAD relies on the use of corrosive agents, detrimental for the environment. This paper reports an environment friendly chemoenzymatic procedure to obtain PPD starting from simple aromatic dithiols.RESULTS The enzymatic reaction was carried out in an aqueous mixture with acetonitrile as co‐solvent, using 1,4‐ and 1,3‐benzenedithiol as monomers and a fungal laccase ( EC 1.10.3.2) as catalyst. The products obtained were identified as mainly cyclic aromatic disulfides. Thermal analysis suggested that the enzymatically‐synthesized CAD display thermal stability and are amenable precursors of high molecular weight sulfur‐containing polymers through solvent‐free, melt ring opening polymerization ( mROP ). After mROP , polymeric molecules around 12.8 kDa were obtained and identified as PPD . The resultant PPD shows uniform size, resistance to temperatures up to 400 °C and electrical insulating properties.CONCLUSION Laccase‐catalyzed synthesis of CAD represents a novel reaction, not previously described elsewhere for oxidoreductases. A 100% substrate conversion was achieved under mild reaction conditions and no over‐oxidation of CAD was observed, representing an advantage over chemical synthesis. The CAD products precipitated completely from the reaction medium, thus simplifying the purification process. © 2017 Society of Chemical Industry