Prediction of crosslinking in polyamides containing the diacetylene functionality

The potential for crosslinking in various polyamides containing the diacetylene moiety has been investigated via computer simulation. Results of simulations performed on an aliphatic, diacetylene-modified polyamide concurred with earlier experimental work, in that the reaction of adjacent diacetylenes was predicted to occur only between mutually hydrogen bonded chains. Hydrogen bonding was predicted to remain intact subsequent to this reaction, also in agreement with experiment. Conversely, other structural arrangements consequent to crosslinking were not predicted accurately. Possible reasons for this disparity have been discussed. A similar study on a diacetylene-modified PPTA system, for which no experimental work exists, has also been conducted. Molecular mechanics simulations indicate crosslinking in this system would be most probable between mutually hydrogen-bonded chains. However, taking into account room temperature thermal vibrations, a three-dimensional network of covalent bonds is predicted. (C) 2000 Elsevier Science B.V. All rights reserved.