A Comprehensive Study of the Properties of Polypropylene Glycol 1025 (PPG1025) using a Combination of Two Theoretical Models, the Simha–Somsenki (SS) Model and the Cahen–Hilliard (CH) Equation

Salwa Hatm Shukur; Saygin Muhammad  Nuri

doi:10.17605/cajmns.v6i4.2903

Salwa Hatm Shukur Department of Physics, College of Education for pure Science, Kirkuk University, Iraq
Saygin Muhammad Nuri Department of Physics, College of Education for pure Science, Kirkuk University, Iraq

DOI: https://doi.org/10.17605/cajmns.v6i4.2903

Keywords: Thermophysical Modeling, Gradient Energy Coefficient, Surface Tension Analysis, Molecular Packing, Void Fraction, Thermal Expansion Behavior, Density–Temperature Relationship

Abstract

In this study, the thermal and physical properties of polypropylene glycol PPG1025 were investigated using a combination of the modified Simha–Somcynsky cell theory and the Cahn–Hilliard equation, with the aim of analyzing the effect of temperature and molecular weight on specific volume, density, surface tension, and energy difference coefficient. Experimental data was used within the Wolfram Mathematica environment with the Newton–Raphson algorithm to obtain accurate solutions to nonlinear equations and reduce the error ratio. The results showed that the specific volume increases with rising temperature while the density and surface tension gradually decrease, and the fraction of voids within the polymer structure increases. The limiting energy coefficient and site occupancy index also showed regular changes reflecting the flexibility and stability of the PPG1025 molecular network within the studied temperature range, confirming the efficiency of theoretical models in predicting polymer behavior.

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