The role of symmetry in crystallization and polymerization phenomena

✍ Scribed by Ham, George E.

• Publisher: John Wiley and Sons
• Year: 1962
• Weight: 504 KB
• Volume: 61
• Category: Article
• ISSN: 0022-3832
• DOI: 10.1002/pol.1962.1206117203

✦ Synopsis

Abstract

Crystallization mechanisms are interpreted as processes in superimposition of molecules from random positioning in space. It is shown that at the melting point there are substantial restrictions on the number of configurations (i.e., ordering) available to molecules, and that this preordering is an important factor in crystallization, influencing melting point, entropy of fusion, and heat of fusion. The interpretation of the melting behavior of nylon 6, nylon 66, polypropylene, and linear polyethylene proceeds from these considerations. The polynuclear hydrocarbons are also considered in detail as prototypes for preordering effects in the melt.