It is very interesting question. Is there exists dependence between elastic and viscous properties of polymer (for example rubber) or these parameters are independent? Usually when we draw the plot between these characteristics it are in the corridor, but tendence is evident. The higher modulus the higher loss factor. But will thise tendence valid under different temperature or for raw compounds and vulcanit rubbers, polyurethane and so on........ Did you see the empirical or theoretical dependence?
Thank you very much for any help. Alexander Kren