Oxygenated species functionality are being introduced to the surface as a result of CDT, leading to changes in surface energy On CDT of Types 1-3 coatings extraneous surface species removed revealing core organic components used in the bulk of the binder. CDT on Type 4 material removes organic materials revealing inorganic components It is evident that there are further topographical, morphological and chemical changes on CDT which will become relevant in understanding how the polyurethane foam precursor components interact, which will be relevant in later Chapters. In the next Chapter the polyurethane foams which are applied to the coated substrates are characterised. Polyurethane Introduction In the preceding Chapters the substrates, coatings and treatment processes were examined, in this Chapter a comprehensive understanding of the filling of the sandwich panel, the polyurethane foams, is provided. This includes analysis of the individual components. As reported in the literature review the findings of Shimizu demonstrated that polyurethane foam catalysts can migrate through to an interface when polyurethane foam is applied to a number of different metals. Thus the characterisation of the principal components used in the manufacture of the polyurethane foam as well the typical formulation used in the Arcelor product was carried out. The full formulation is made up of many chemicals; catalysts are required in the isocyanate PUR/PIR processes as well as for the blowing process. The addition of surfactants is included to help control the cell size and structure. These tend to silicone based and are known to show a characteristic peaks at 147 u (Si2C5H15O+). Flame retardants are included in the formulations to comply with fire standard within the construction industry. Blowing
Oxygenated species functionality are being introduced to the surface as a result of CDT, leading to changes in surface energy On CDT of Types 1-3 coatings extraneous surface species removed revealing core organic components used in the bulk of the binder. CDT on Type 4 material removes organic materials revealing inorganic components It is evident that there are further topographical, morphological and chemical changes on CDT which will become relevant in understanding how the polyurethane foam precursor components interact, which will be relevant in later Chapters. In the next Chapter the polyurethane foams which are applied to the coated substrates are characterised. Polyurethane Introduction In the preceding Chapters the substrates, coatings and treatment processes were examined, in this Chapter a comprehensive understanding of the filling of the sandwich panel, the polyurethane foams, is provided. This includes analysis of the individual components. As reported in the literature review the findings of Shimizu demonstrated that polyurethane foam catalysts can migrate through to an interface when polyurethane foam is applied to a number of different metals. Thus the characterisation of the principal components used in the manufacture of the polyurethane foam as well the typical formulation used in the Arcelor product was carried out. The full formulation is made up of many chemicals; catalysts are required in the isocyanate PUR/PIR processes as well as for the blowing process. The addition of surfactants is included to help control the cell size and structure. These tend to silicone based and are known to show a characteristic peaks at 147 u (Si2C5H15O+). Flame retardants are included in the formulations to comply with fire standard within the construction industry. Blowing
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