Aromatic polyamides. VI. Thermal behavior of model diamides

✍ Scribed by Y. P. Khanna; E. M. Pearce; D. A. Vernick

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: English
• Weight: 217 KB
• Volume: 27
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1982.070270638

✦ Synopsis

Aroma tic Polyamides. VI. Thermal Behavior o f Model Diamides

Many liquids can be solidified in the glassy state if they are cooled more rapidly than the time required for crystal nuclei formation. This is easy to do with polymers which, because of their longer chain structures and chain entanglements, cannot fit into the crystal lattice upon rapid cooling. However, low-molecular-weight materials are difficult to obtain in the glassy form. Although glass transition is exhibited by many low-molecular-weight compounds,lS2 it is by no means universal as it is for polymeric materials. During the course of characterizing some aromatic diamides (mol wt 31&385), we observed that these compounds exhibit very large super coolings and can be quenched to the glassy state just like poly(ethy1ene terephthalate).

In this note we describe the phenomenon of glass transition, cold crystallization, and melting of some aromatic diamides. Structural effects on these transitions and thermal stability are also considered.