8/23/2023 0 Comments How to test slip viscosity![]() ![]() ![]() Figure 2: A generic modulus-temperature map for polymers. It provides a map of a vital engineering property, and is also a fingerprint of the molecular motions available to the material. Clearly, a plot of modulus versus temperature, such as is shown in Figure 2, is a vital tool in polymer materials science and engineering. ![]() Neither the glassy nor the rubbery modulus depends strongly on time, but in the vicinity of the transition near \(T_g\) time effects can be very important. If the material is not crosslinked, the stiffness exhibits a short plateau due to the ability of molecular entanglements to act as network junctions at still higher temperatures the entanglements slip and the material becomes a viscous liquid. Differentiation of this expression gives the slope of the stress-strain curve at the origin as \(E_r = 3NRT\). Where \(\sigma\) is the stress, \(N\) is the crosslink density (\(mol/m^3\)), and \(\lambda = L/L_0\) is the extension ratio. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |