Abstract
The aim of this thesis was to build an atomistic model based on experimental information and to use simulation methodologies and theories to determine the mechanical and physical properties of a linear epoxy polymer. The atomistic behaviour of the polymer was studied during the property determining simulations, in an attempt to gain fundamental atomistic information. The introductory chapter 1 is made up of four parts. The first section is a very general introduction to polymer science giving a newcomer to the field an appreciation of the concepts used, while the second section introduces the chemistry of epoxy resins and their commercial uses. The third section is a very brief introduction to how molecular modelling can be used to bridge the gap between experimental and theoretical studies, while the final section reiterates the aims, and outlines how the research was conducted. The characterisation of a linear epoxy polymer by spectroscopic and chromatographic methods is described in chapter 2. The physical and mechanical property tests were also conducted and the results were coupled to structural information. The main object of this section was to quantify the relationship of the physical properties with the degree of cure. The concept, methodologies and techniques of molecular modelling are introduced and discussed in greater detail in chapter 3. To demonstrate the modelling techniques used, the mechanical properties of simple polyethylene-like models were studied and compared with experimental data. Chapter 4 characterises the structure of the linear epoxy polymer using representative atomistic models which were based on structural information from chapter 2. Additional crystallographic data was used to validate the force field parameters used in the modelling studies, to justify the motions of the molecular chain, and to qualitatively quantify the response of linear chains to stress and temperature. The simulation and empirical calculations for the determination of both physical and mechanical properties were calculated and are discussed in chapter 5. Comparisons were made between all three techniques; experimental, computer experiment and theory, and showed good agreement. Finally, in chapter 6, a brief summary is given of the results in previous chapters, with further discussion on the implications of these results and suggestions on possible areas of future work.