AN INTRODUCTION TO PLASTICS - Plastics and Environmental Sustainability - page 80

not equally likely due to steric effects of substituents on neighboring repeat
units. Taking these perturbations into account yields the following
refinement:
(3.2)
where ϕ is the torsional angle. However, a detailed discussion of these
models and the statistical treatment of polymer chains are beyond the scope
of the present discussion. It is sufficient to appreciate that all
representations are crude models of polymer chains and that invariably
depends on the bond length, the bond angles, as well as the substituents on
adjacent repeat units. In 2D space, freely-jointed chain of a high polymer
looks like the “random-walk” path or the tracing of the movement of a
particleinBrownianmotion(see Fig.3.3 ) .Thispictureisverydifferentfrom
the simple structural models used to draw polymer structures but closer to
the 3D image obtained using profiling microscopy ( Fig. 3.2 ) .