No abstract

No abstract

The relation between PVT and rheological measurements of several polymer melts including polyethylenes, polypropylene, polystyrene, poly(methyl methacrylate), and polycarbonate has been taken into investigation. Pressure-temperature dependent viscosities, determined on rotational and backpressure-modified capillary rheometers, were fitted through the Carreau-Yasuda model. PVT data was analyzed by the help of the Simha-Somcynsky equation of state (SS EOS). The thermodynamical parameters of the SS EOS were connected to constant-stress viscosity (experimental) and zero-shear viscosity (extrapolated). The Doolittle relationship was modified into the form of . The relation was employed and tested for the data evaluation. It proved to be a good tool for linearization of PVT and rheological data.

No abstract

Montmorillonite nanoclay and polyurethanes obtained from polyethylene glycol (PUR 400) and polyoxypropylene diol (PUR 1002) were used to enhance the mechanical properties of an epoxy resin. Maximum impact strength improvement was obtained with compositions containing 2% nanoclay and 10% PUR 400 as well as that with 1% nanoclay and 15% PUR 400, corresponding to 110% and 75%, respectively, in relation to the unmodified epoxy resin. Moreover, a 10-fold increase was observed with respect to the flexural strain at break for the composition containing 15% PUR 1002 and 2% nanoclay.