Glass engineering of aminotriazine-based materials with sub-ambient Tg and high kinetic stability


Article
Version acceptée / Accepted Manuscript

Date de publication

Identifiant ORCID de l’auteur

Contributrices et contributeurs

Direction de recherche

Publié dans

CrystEngComm

Date de la Conférence

Lieu de la Conférence

Éditeur

Royal Society of Chemistry

Cycle d'études

Programme

Organisme subventionnaire

Résumé

A challenge in glass engineering is the design of molecular glasses combining a high glass kinetic stability (GS) of the amorphous phase with a low (sub‐ambient) glass transition temperature (Tg). Triazine derivatives with arylamino substituents readily form glassy phases that can show outstanding resistance to crystallization. In the present study, a series of 12 analogous compounds incorporating phenylamino and cyclohexylamino groups was synthesized, and their thermal properties and intermolecular interactions were studied. All compounds possess an excellent glass‐forming ability, a low Tg ranging from 32 °C to as low as ‐19 °C, and a high GS. While the cyclohexyl derivatives show higher Tg, the phenyl derivatives possess a higher GS with some compounds remaining completely amorphous for over three years despite their sub‐ambient Tg. X‐ray diffraction, infrared spectroscopy and DFT calculations reveal that the higher volume occupancy and rotational energy barrier of cyclohexyl groups are the main factors responsible for the compounds’ higher Tg values but that they also contribute to their higher propensity to crystallize. In counterpart, the planarity of phenyl groups leads to poorer packing and enhances their GS while keeping their Tg well below ambient. The formation of hydrogen bonds or competing interactions provides an additional handle to tune the Tg of the compounds. Taken together, these studies provide guidelines for the design of molecular glasses with readily tunable thermal properties in view of their functionalization.

Table des matières

Notes

Notes

Autre version linguistique

Ensemble de données lié

Licence

Approbation

Évaluation

Complété par

Référencé par

Ce document diffusé sur Papyrus est la propriété exclusive des titulaires des droits d'auteur et est protégé par la Loi sur le droit d'auteur (L.R.C. (1985), ch. C-42). Sauf si le document est diffusé sous une licence Creative Commons, il ne peut être utilisé que dans le cadre d'une utilisation équitable et non commerciale comme le prévoit la Loi (i.e. à des fins d'étude privée ou de recherche, de critique ou de compte-rendu). Pour toute autre utilisation, une autorisation écrite des titulaires des droits d'auteur sera nécessaire.