Many different polyolefinic foams and effectivelynonfoamable polyolefinic resins were studied by ASTMD-4440, “Standard Test Method for Plastics: Dynamic Mechanical Properties Melt Rheology” techniques [1].  The sensitivity of this test method to chain branching of the polymeric molecule was maximized by optimization of the test setup parameters. With the optimized test setup, the melt viscosity, which is also known as complex viscosity, and the viscoelastic properties of storage and loss modulus were measured for the various materials.  The functional relationship between the loss tangent, tan δ, which is defined as the damping of the material from the loss modulus divided by the storage modulus, and the complex viscosity characterizes each polyolefin material.