Using synchrotron SAXS and WAXS, we investigated crystalline structures including crystallite size, lamellar thickness, long spacing of syndiotactic polypropylene （sPP） and poly（ethylene-co-octene） （PEcO） that crystallized from the sheared melt. The independence of the shear effects on the crystalline structures and the shear related lamellar orientation indicate the stable mesophase. Experiments on the different shear effects on polymer various crystalline structures confirm the multi-step polymer crystallization process.
The calculations presented in this paper are based on the Sanchez-Lacombe（SL）lattice fluid theory.The interaction energy parameter,g12/k,required in this approach was obtained by fitting the cloud points of polystyrene（PS）/methylcyclohexane（MCH）polymer solutions under pressure.The SL lattice fluid theory was used to calculate the spinodals,the binodals,and the Flory-Huggins（FH）interaction parameter of the solutions.The calculated results show that the SL lattice fluid theory can describe the dependences of thermodynamics of PS/MCH solutions on temperature and pressure very well.However,the calculated enthalpy and the excess volume changes indicate that the Clausius-Clapeyron equation cannot be suitable to describe pressure effect on PS/MCH solutions.Further analysis on the thermodynamics of this system under pressure shows that the role of entropy is more important than the excess volume in the present case.
