Polymer Science and Technology, 3rd Edition

Chapter 5. Viscoelasticity and Rubber Elasticity

At the extremes, a polymer may exhibit mechanical behavior characteristic of either an elastic solid or a viscous liquid. The actual response depends upon temperature, in relation to the glass-transition temperature (T_g) of the polymer, and upon the time scale of the deformation. Under usual circumstances, the mechanical response of polymeric materials will be intermediate between that of an ideal elastic or viscous liquid. In other words, polymers are viscoelastic. This behavior is readily illustrated by Silly Putty, which is a silicone rubber having a low T_g. If rolled up into a ball and dropped to the floor, it will bounce with the resilience of a rubber ball. This is a manifestation of elastic ...