RESUMO
Polymer interlayer materials are utilized in laminated glass systems to provide increased resilience from blast incidents. The polymer chains within the interlayer material can benefit from material modifications that increase the crosslinking between adjacent chains. One theorized method of targeted crosslinking is made possible through a boron neutron capture process. This process utilizes neutron radiation that bombards boron material, thus producing emissions of highly energetic particles into the polymer. The method has been experimentally utilized for bulk material processing as well as surface treatment. The surface treatment process has been extensively investigated in this study to manipulate polymers commonly used as interlayer material. Comparison evaluation tests have been completed to show the material behavior change through static tensile loading, dynamic tensile loading, indentation testing, and scratch resistance testing. Results present the specific material behavior changes, effects on different interlayer material, and optimizations for the treatment processes. Data resulting from these tests will expand the understanding of the material behavior changes from treatment techniques and show evidence of the expected crosslinking. This understanding will lead to a quantifiable application of system capacities to improve the future designs of the window and building systems and lead to a safer, more secure, and resilient infrastructure. Polymer treatment by boron neutron capture radiation has produced polymer interlayers with the potential of increased resilience to blast. The research to date has evaluated treated polymers and shown that the hardening and increased elasticity of the material can be initiated through treatment, thus indicating crosslinking behavior. These results show distinct changes in the material behavior, particularly with the EVA interlayer material. The harder surface of the interlayer may resist the cutting of the interlayer surface by glass shards. Scratch resistance was 30% higher and the measured hardness was 100% on treated surfaces. Treated EVA exhibited a 40% higher stress capacity, a 35% higher toughness, and a 40% increase in the elasticity of the material. The overall toughness increase of the treated polymer material allows for a higher energy absorption, and an overall improvement of window performance in blast conditions. The treatment technique can be applied to a variety of window interlayer products for optimal material performance in blast conditions.
RESUMO
It is known that weathering action has a significant impact on polymer interlayer materials, and previous studies have evaluated certain aspects of weathering such as temperature, humidity, and UV radiation. In this paper, the environmental effect on the mechanical properties of the virgin and cured/processed polymer interlayer materials will be studied. Three polymer interlayer materials were focused, i.e., Polyvinyl butyral (PVB), Ethylene-vinyl acetate (EVA), and Ionomer (SG), due to their industrial interest. Testing setups were designed to apply the environmental effects and perform mechanical testing on the polymeric materials. Four environmental effects were studied, including water submersion (E1), constant high temperature (E2), cyclic temperature with low relative humidity (E3), cyclic temperature, and relative humidity (E4). After the exposure of these materials to these environmental effects, the samples were prepared and mechanically tested. Uniaxial tests were performed under static and high strain rates (around 45-1). It was found that under dynamic load, the properties of EVA such as the strength, maximum strain, and the toughness were not significantly affected by the environmental effects. SG5000 properties were significantly affected.
