| Abstract: | The mechanical loss maximum in polycaprolactam in the vicinity of –50°C at a frequency of  10 Hz ( transition) was shown not to be related directly to the presence of moisture in the polymer. This transition is also observed in dried caprone (vacuum drying at 10–4 torr and 180°C for 30 h) after a few days following annealing. The maximum was shown by IR spectroscopy to decrease and shift towards lower temperatures when hydrogen bonding is weakened as a result of prior heating or compression strain. A conclusion is drawn concerning the relationship between the transition and hydrogen bonding which fixes the amide groups in the amorphous polymer phase.M. I. Kalinin Leningrad Polytechnic Institute. A. F. Ioffe Physical Technical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 5, pp. 919–922, September–October, 1972. |
