PU/BMA copolymer IPNs

Creep rate spectroscopy has been used for the discrete dynamic analysis of polymer networks such as PU network [19] PU-butyl methacrylate/dimethacrylate triethylene glycol copolymer interpenetrating networks (PU/BMA copolymer IPNs) [132, 133] commercial epoxy networks [134,135] the model epoxy-amine networks varying in crosslink density and rigidity [20] and the cross-linked hyperbranched polyimides [136],... 

Table 3 Possible kinds of segmental motion within the broadened glass transition in the PU/BMA copolymer IPNs, and their characteristics expected [133]...

Creep rate spectroscopy allowed us not only to estimate the dynamic heterogeneity but also to probe local (nanoscale) compositional inhomogeneity in the PU-BMA copolymer IPNs. For this purpose, the relative peak contributions to dynamics around Tg as a function of IPN composition were estimated. On this basis, the volume fractions of the nanodomains of neat constituent networks as well as their miscibility degree as a function of IPN composition could be determined, in a semi-quantitative way [133]. 

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