CHAOS IN POLYMER PHASE TRANSITIONS (C 93431 Principal Investigator: Michael S. E&on Chapter 1. Phase space analysis of TSC data for evidence of chaos in polymer chain motion.

1. Aliphatics (PE, PP, PVC, PMMA, and PS). These are vinyl polymers, with pendant groups of varying size. 2. Aromatics (PC, PET, PEN). The rigidity of the backbone varies within this group. 3. Polyamides (Nomex, Nylon 6, Nylon 11, Nylon 4,6, Nylon 6,6, Nylon 6,12). With the obvious exception of the Nomex sample, these polymers are aliphatics, as are group 1, but with strong hydrogen bonding because of the amide groups. Nomex, with an aromatic backbone was chosen as a cross check with group 2 polymers. Representative phase space trajectories from the TSC data from these materials show their commonalities and differences (Figures l-3). The dominance of the loop, which is remincent of a limit cycle attractor (NTC 94, p. 129, Fig 3), for the vinyl polymers is dependent upon the size of the pendant group: a larger group generally produces a more dominant circle. The trajectory formed in the phase space of the category 2 polymers has an indistinct attractor-like structure in a very limited region. This we presume to be a consequence of the lack of a significant pendant group and/or the rigidity of the bvackbone. Finally, for all the category three polymers there was rarely a circular-shape to be found the the phase space. This may well be explained on the basis of the stmg hydrogen bonding present in these materials.