سال انتشار: ۱۳۸۲

محل انتشار: هشتمین کنگره ملی مهندسی شیمی ایران

تعداد صفحات: ۱۰

نویسنده(ها):

Ali Haghtalab – Department of Chemical Engineering, Tarbiat Tehran, Iran
Gholamhossein Sodeifian – Department of Chemical Engineering, Tarbiat Tehran, Iran

چکیده:

Frequency sweep experiments were performed on poly(vinyl chloride) (PVC) and acrylonitrile butadiene rubber (NBR) as well as their miscible blends; i.e. PVC/NBR by mechanical EOHQGLQJDW C o . In order to investigate the validity of time temperature superposition (TTS) principle, curves of loss angle ) (d
versus the logarithm of absolute value of complex modulus, *) log( G , have been plotted. It has been shown that the TTS principle is not valid for the above-mentioned polymer materials and therefore, they are not t hermorheologically simple. Meanwhile, master curves of PVC, NBR and PVC/NBROHQG ZHUH REWDLQHGapproximately. Using a nonlinear regression method, discrete relaxation spectra have been determined for 39& 1 %5DQG 39& 1 %5 7R VWXGnon-linear viscoelasticity behavior, the
experiments of steady shear, start up steady shear and step strain have been carried out. The damping function was determined by the step strain experiments. Using K-BKZ equation, the shear viscosity and the shear stress growth function were calculated from the discrete relaxation spectra and the damping function, and then compared to experimental data. The K-BKZ constitutive equation provides very good prediction over the entire range of experimental results, particularly; it predicts the main features of
the experimental data.