Dynamic shear measurements in dilute solutions of polyethylene oxide of low concentration

Abstract

Dynamic shear characteristics G′ ( ω) and G″ ( ω) of dilute solutions of polyethylene oxides WSR-301 of a concentration 5×10 −5 g/g and molecular weight ≈5×10 6 were determined experimentally at frequencies ranging from 20 to 300 c/s. From the elastic part of the shear modulus the characteristic time of relaxation τ≈10 −2 sec was calculated. The experimental result obtained is in agreement with information published previously [1–3] and enables the effect of small polymer additives on the reduction of the coefficient of turbulent friction to be explained from the point of view of the theory of visco elasticity. It was shown experimentally that the elastic modulus G ( ω) of a polyethylene oxide solution varies according to time, reaching an equilibrium value. The time during which this is achieved depends on conditions of preparation (temperature and mechanical action).