Dynamic viscoelastic properties of free radical bulk polymerizing systems under near-isothermal and non-isothermal conditions

摘要: Dynamic viscoelastic moduli of an example polymerizing system namely the free radical bulk polymerization methyl methacrylate (MMA), is studied using a Haake® rheometer–reactor assembly and adapted HV-DIN cup-and-bob assembly. A series experiments on MMA under different temperature histories (isothermal, step-increase step-decrease) at two initiator [2, 2′-azoisobutyronitrile (AIBN)] concentrations, have been carried out. The data storage modulus, G′, loss G″, phase shift, δ, are measured during course polymerization, well into gel effect region. new correlation developed for these properties. kinetic model zero-shear viscosity, presented in our earlier studies, used this generalized correlation. so observed to represent experimental quite variety histories. characteristic relaxation time, τi, representing be larger than Rouse value, τR, by factor about seven. findings agreement with several other studies entangled non-polymerizing systems.