Molecular thermodynamics of polymer melts at interfaces

Technical Report · Thu Sep 01 00:00:00 EDT 1988

DOI:https://doi.org/10.2172/6227886· OSTI ID:6227886

Theodorou, D N

A lattice model is developed for the prediction of structure and thermodynamic properties at free polymer melt surfaces and polymer melt/solid interfaces. Density variations in the interfacial region are taken into account by introducing voids in the lattice, in the spirit of the equation of state theory of Sanchez and Lacombe. Intramolecular energy (chain stiffness) effects are explicitly incorporated. The model is derived through a rigorous statistical mechanical and thermodynamic analysis, which is based on the concept of availability. Two cases are considered: ''full equilibrium,'' whereby the interfacial polymer is taken as free to exchange heat, work and mass with a bulk polymer phase at given temperature and pressure; and ''restricted equilibrium,'' whereby a thin polymer film is allowed to equilibrate locally in response to ambient temperature and pressure, but in which chains do not necessarily have the same chemical potential as in the unconstrained bulk. Techniques are developed for calculating surface tension, adhesion tension, density profiles, chain shape, bond orientation, as well as the distribution of segments of various orders in the interfacial region. 28 refs., 6 figs.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6227886
• Report Number(s): LBL-26018; ON: DE89008853
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
INTERFACES
PHASE STUDIES
POLYMERS
SURFACE PROPERTIES
ADHESION
EQUATIONS
EQUATIONS OF STATE
EQUILIBRIUM
LIQUIDS
MATHEMATICAL MODELS
MOLECULES
SOLIDS
SURFACE TENSION
TEMPERATURE DEPENDENCE
THERMODYNAMICS
VOIDS
FLUIDS
360602* - Other Materials- Structure & Phase Studies
360603 - Materials- Properties
400201 - Chemical & Physicochemical Properties