Organic monomeric glasses: A novel class of materials, Michel F. Molaire, Roger W. Johnson

molecular glass model

 
Journal of Polymer Science Part A: Polymer Chemistry

Volume 27, Issue 8, pages 2569–2592, July 1989

 

Abstract

An amorphous monomeric glass is defined as a mixture of compatible organic monomeric molecules with an infinitely low crystallization rate under the most favorable conditions. These mixtures can be formed in a one-part reaction of a multifunctional nucleus with a mixture of substituents. The “noncrystallizability” of the mixture is controlled by the structural dissymmetry of the nucleus and/or the substituents and the number of components making up the mixture.
We have developed an equation to calculate the number of components in a given mixture, knowing the structure and functionality of the nucleus and the number of substituents. An HPLC characterization method was developed and used to investigate the effects of various reaction conditions on the component concentration distributions and physical properties of the resulting materials. A dissymmetry number defined as the total weight percent of odd-substituted components is believed to be a potential measure of the “noncrystallizability” of the mixture. Physical properties such as glass-transition temperature can be dramatically increased through controlled oligomerization at the price of a moderate increase in melt viscosity. 
The organic monomeric glasses, like amorphous polymers, have good film-forming properties. However, unlike polymers, they display extremely low melt-viscosities and large positive entropy-of-mixing values and can be ground easily into extremely small particles. These properties make them ideal for certain applications where compatibility, melt-flow, and small particle size are important.