Structure of polymer molecules stretched or coiled?
In the context of structure-property relationships, the structure of polymer molecules with flexible bonds can be treated. If the bonds are flexible, then the orientation of the segments of a polymer is random. The random walk model (RW) is suitable for simulation. The RW represents a sequence of N displacements in a random direction. When simulating the configuration of a polymer molecule, each shift corresponds to a segment of the molecule. The mean square end-to-end distance <R2> is used as a measure of the shape of the polymer.
Through haptic simulations of the RW, learners arrive at the relationship <R2>=N, which corresponds to a knotted structure and not an elongated molecule. Further applications of such simulations are investigations into the behavior of polymers in restricted geometry and rubber elasticity.
