|Title||Asymmetric Monomer, Amorphous Polymer? Structure-Property Relationships in 2,4-FDCA and 2,4-PEF|
|Author(s)||Nolasco, Mariela M.; Araujo, Catarina F.; Thiyagarajan, Shanmugam; Rudić, Svemir; Vaz, Pedro D.; Silvestre, Armando J.D.; Ribeiro-Claro, Paulo J.A.; Sousa, Andreia F.|
|Source||Macromolecules 53 (2020)4. - ISSN 0024-9297 - p. 1380 - 1387.|
|Department(s)||BBP Sustainable Chemistry & Technology|
|Publication type||Refereed Article in a scientific journal|
The biobased polyester poly(ethylene 2,4-furanoate) (2,4-PEF) is a potentially interesting yet insufficiently studied polymer whose resistance to crystallization fundamentally stems from the asymmetric nature of the 2,4-furandicarboxylic acid monomer. A combination of vibrational spectroscopy (infrared, Raman and inelastic neutron scattering) and ab initio calculations has been used to assess the conformational and regiochemistry preferences of 2,4-PEF. The latter polymerizes following a random distribution of monomer orientation, thereby rendering the formation of periodic interchain C-H···O contacts wholly unfeasible and ultimately favoring the formation of randomly coiled chains based on gauche-ethylene glycol segments. In the absence of C-H···O stabilization, the ordered crystalline arrangement is disfavored and polymer chains - adopting several quasi iso-energetic structures - prefer to solidify into an amorphous mess.