Лако-красочные материалы — производство

A. Pizzi

Ecole Nationale Superieure des Technologies et Industries du Bois, Universite de Nancy l, Epinal, France

I. INTRODUCTION

Molecular mechanics in the broader sense of the term is a computational technique which is, among other things, particularly suited for determining at the molecular level the interactions at the interface of well-defined polymers. It has already been used, in many fields, for instance, to calculate the most stable conformation, hence the conformation of minimum energy, of biological materials such as proteins, for the interactions of oxygen, carbon monoxide, and carbon dioxide on the functioning of the heme of respiratory proteins, for the design and activity forecasting of pharmacological drugs or other biolo­gically active materials to fit the active sites of enzymes, for the determination of the structure of a variety of high-tech materials, to determine the structure and properties of a variety of synthetic and natural polymers, and even to model homogeneous and heterogeneous catalysis processes. The variety and number of applications of this techni­que in the past few years are indeed great and it has positively influenced many fields of science.

What exactly is molecular mechanics? It is the study of the interactions of non covalently bonded atoms in one or more molecules which determine the spatial conforma­tion of such a structure or its change of conformation induced by a neighboring molecule. In short, it is the modeling of the structures of molecules, their structural interactions and modifications, and hence of their macroscopic and microscopic properties derived from the molecular level according to first principles in physics and physical chemistry. Its mundane appearance is that of a computational technique, and today extensive computa­tion is always included. However, it is indeed much more than just a computational technique: it is the technique par excellence to explain our physical world from first, molecular, and atomic principles.

While it has now been used for almost thirty years in many other fields the applica­tion of this technique in the field of adhesion and adhesives, namely to theoretical and applied problems of adhesion and to the optimization of adhesion, is still relatively in its infancy. A few notable applications of this technique to adhesion and adhesives do, how­ever, exist and this chapter is aimed at describing them, and their relevant consequences without pretending to be either exhaustive or limiting as to what regards any other future applications. As molecular mechanics and molecular dynamics are really ‘‘going back to basics’’ techniques aimed at explaining at molecular level the behavior of materials, there is no doubt that their use is also bound to grow in the field of adhesion just as rapidly and effectively as it has occurred in other scientific and technological fields, once the potential of such a technique is understood.

In the field of adhesion, in its broadest sense, several different pioneering trends are already on record, namely:

(i) studies of the adhesion of generalized particles to generalized surfaces, or of generalized particle to generalized particle

(ii) studies of the adhesion of polymers well defined at molecular level to surfaces equally well defined at molecular level

(iii) studies of the dynamic, differential, competitive adsorption, hence adhesion, of molecularly well-defined oligomers to an equally molecularly well-defined sur­face in the presence of solvents, such as, for instance, in the modeling of chromatography.

This chapter will address these three sectors of activity.