@article{article_201813, title={EFFECT OF TACTICITY ON VISCOSITY-HOLE FRACTION BEHAVIOR OF ATACTIC AND SYNDIOTACTIC POLYSTYRENES}, journal={Journal of the Turkish Chemical Society Section A: Chemistry}, volume={2}, pages={12–14}, year={2015}, DOI={10.18596/jotcsa.57327}, author={Dinç, Fatma and Sorrentino, Andrea and Tav, Cumali and Yahşi, Uğur}, keywords={Ataktik ve sindiyotaktik polistiren, sıfır kayma viskozitesi, sabit kayma-gerinim hızı viskozitesi, boşluk kesri, viskoholibilite, Simha-Somcynsky}, abstract={The non-Newtonian viscosity of  atactic and syndiotactic polystyrenes from 200 to 300˚C temperature range at various pressures is described well using our recently proposed YDT (Yahsi-Dinc-Tav) and the Cross models [1]. The Pressure-Volume-Temperature (PVT) data of atactic and syndiotactic PSs are fitted to the Simha-Somcynsky equation of state (SS) [2], to  calculate  the  characteristic  parameters,  such  as  P∗ V∗, T∗ and  the  hole  fraction.  The relationships  among PVTh values  are  elucidated  both  with  the  Simha-Somcynsk y  Hole Theory and the previously obtained various Tait equations. The application of the linear dependency of our derived quantities; zero shear and constant shear-rate viscosities with hand Tdependent “thermo-occupancy” function (Yh) leads to extract novel conclusions on the  differences  between  both  types  of  PSs.  In  particular,  as  given  in  Figure  1,  the viscoholibility (the derivative of the logarithm ofviscosities) decreases with the increasing hole fraction,h, computed from the SS theory.}, number={2}, publisher={Turkish Chemical Society}