Structure-property relationships of electron beam-irradiated monomeric and polymeric systems.

摘要

Structure-property relationships were investigated for electron beam(EB) irradiated monomeric and polymeric systems. The objectives were to study the feasibility of preparing systems of potential application, and to characterize these systems in terms of structure-property behavior. In this thesis, the basic theories on radiation chemistry were first reviewed. Next, five different studies on the application of EB radiation were discussed.; In the first study on the surface modification of the methacrylic acid derivative of the glycidyl ether of bis-phenol A(bis-GMA) substrates, considerable changes in wetting characteristics were observed using functionalized poly(dimethyl siloxane)(PDMS) oligomers as surface modifiers. Systematic studies were conducted to investigate the effects of the type of functionality, the molecular weight of PDMS and the radiation dosage, etc. The second subject was on the structure-property behavior of EB cross-linked caprolactone-allyl glycidyl ether(CL-AGE) copolymers. EB radiation was utilized to crosslink these materials at various temperatures both above and below the crystalline melting point. The final solid state properties were found to be strongly dependent on the morphological state of the CL-AGE copolymer at the time of EB irradiation. In the third study, models of time-temperature-energy(TTE) diagrams in an idealized EB radiation curing system were developed to help provide a conceptual understanding of the TTE relationship. Three general adiabatic cases were presented with increasing degree of complexity: the first considered only heating through EB energy dissipation, while the second and third attempted to include a kinetic exotherm, and the effects of glass transition and vitrification behavior, respectively. The fourth study focused on the effects of EB irradiation on the mechanical and thermal properties of poly(phenylene sulfide). The effects of morphological state and atmospheric environment such as air or nitrogen during the irradiation process were investigated in terms of structure-property behavior. In the fifth study, two systems(symmetric and asymmetric) based on the controlled distribution of bis-GMA within a crosslinked nitrile rubber(NBR) network were prepared utilizing EB irradiation. The prepared symmetric and asymmetric distributions of bis-GMA and the morphological structure of the NBR/bis-GMA system were investigated by dynamic mechanical as well as by FTIR and polarizing optical microscopy analyses.