SynopsisSurface modification of polymer films via electron beam irradiation was studied using the methacrylic acid derivative of the diglycidyl ether of bisphenol A, commonly called bis-GMA, as a curable substrate. Functionalid polydimethylsiloxane (PDMS) oligomers were utilized as surface modifiers. Considerable changes in the wetting characteristics were observed for the siloxane modified bis-GMA surfaces by critical surface tension measurement. For dosages up to 5 Mrads, the dosage level strongly dects the critical surface tension of the polymer. This result implies differences in the concentration of the attached PDMS oligomers to the bis-GMA substrate. The methacrylateterminated PDMS was observed to be more effective in lowering the critical surface tension than a similar vinyl-terminated PDMS. Higher molecular weight and multifunctional PDMS coatings resulted in somewhat lower critical surface tensions in the dosage range applied in this study. The surface thickness of the functionalid PDMS coatings which were bonded to the substrate surface depended on the molecular weight of the surface modifiers as obtained by XPS analysis. Peel tests of the uncoated and PDMS coated bis-GMA clearly resulted in agreement with the critical surface tension data. Chemical inertness and poor wettability of PDMS provided the PDMS coatings with enhanced resistance to chemical degradation caused by a 24-h exposure to aqueous nitric and acetic acid.

Semicrystalline copolymers of caprolactone and allyl glycidyl ether(CL-AGE) have been crosslinked at various temperatures both above and below the crystalline melting point by electron beam irradiation. Gel fraction increases with irradiation dose up to 40 Mrad and shows slightly higher values when irradiated above the melting point compared to irradiation below the melting point. A stable spherulitic crossed polarizer optical microscopy pattern of the CL-AGE copolymer cross linked in the semicrystalline state persisted over a wide range of temperature even in the melt. In contrast, random intro duction of crosslinks into this material in the melt state re sulted in some restriction on the crystallization process limiting the development of ordered superstructure upon solidification.Measurements of thermal and mechanical properties support the gel fraction results and the microscopy observations.It was concluded that the final solid state properties of the EB-irradiated CL-AGE copolymers are strongly dependent on the morphological state of the material at the time of the EB irradiation process.

-In this paper, proposed NED(nuclear event detectors) for detection of a transient radiation. Nuclear event detector was blocked of power temporary for defence of critical damage at a electric device when a induced transient radiation. Conventional NED consist of BJT, resistors and capacitors. The NED supply voltage of 5V and MCM(Multi Chip Module) structures. The proposed NED were designed for low supply voltage using 0.18um CMOS process. The response time of proposed NED was 34.8ns. In addition, pulse radiation experiments using a electron beam accelerator, the output signal has occurred.

SYNOPSISTwo systems based on the controlled distribution of the methacrylic acid derivative of the diglycidyl ether of bisphenol-A (bis-GMA) into crosslinked acrylonitrile-butadiene copolymers, commonly called nitrile rubber ( N B R ) , were prepared utilizing electron beam ( E B ) radiation. In the system called "symmetric," the EB crosslinked NBR was swollen to equilibrium in solutions containing different concentrations of bis-GMA. The swollen NBR film was then EB irradiated to different dosage levels. The other system, called "asymmetric" or "gradient," was prepared by applying the solutions containing bis-GMA to one surface of the EB crosslinked NBR film in a controlled time that was less than the time to achieve an equilibrium concentration across the thickness or "swelling" dimension. This asymmetrically swollen NBR film was then immediately EB irradiated using different dose levels. The prepared symmetric and asymmetric NBR systems were investigated by thermal and mechanical, as well as microscopic, analyses. The mechanical responses were shown to be strongly dependent on the bis-GMA content in the NBR film and the type of preparation history. The dynamic mechanical spectra showed the presence of two transitions, indicating some level of phase separation that was supported by scanning electron microscopy of fracture surfaces for symmetric and asymmetric systems. The asymmetric distribution of the imbibed (cured) monomer in the asymmetric system was confirmed by both FT-IR and optical microscopy analyses.