X-ray diffraction studies on untreated and treated (with sorbic acid) nylon indicated that a greater degree of order results with the sorbic acid molecules acting as the ordering agent.
Application of the Rotinyan-Drozdov equation to kinetic sorption data confirmed that the ratedetermining step is the diffusion step in the plastic.
Diffusion coefficients obtained from the time-lag method approximated within experimental errors those determined by a sorption method (Berthier method).
REFERENCES
aggregates or clusters occurs in the plastic which hinders the over-all migration of individual sorbic acid molecules through the plastic. With more dilute solutions, the mobility of individual molecules increases, and diffusion proceeds at a more rapid rate.
SUMMARY
Studies on the interaction of sorbic acid by nylon 66 were continued for the purpose of ( a ) postulating the mechanism of interaction, (b) verifying the ratedetermining step in the sorption process, and (c) comparing diffusion coefficients by the time-lag method to a sorption method. Results of the various experiments may be summarized as follows.
Dyesorption studies indicated. that sorbic acid was most likely interacting at the amide linkages in the polymer rather than at the end amino groups.
Differential infrared analysis on samples of untreated and treated (with sorbic acid) nylon sug- gested a double hydrogen bond formation between the acid and the nylon, confirming that the previously found AH" of -9.77 was correct.