Glass hardening range

A wide range of physical properties can be achieved by varying the molecular weight of the epoxy component, the type of hardener and by adding catalysts and plasticizers. Epoxy polymers can be reinforced with glass, carbon and synthetic fibres prior to curing to increase strength and flexibility. 

The increase in the glass-transition temperature Tg of a film 0.01 X 10 m thick is associated with limitation of the mobility of the polymer chains near the solid surface. The character of Tg change for the surfaces of basalt-1 and basalt-2 is indicative of a complex structure of the boundary layer. For films (0.01-0.03) x 10 m thick on the log Yg-AjT curve, no fracture is observed in the investigated temperature range. We assume that a bormdary layer of epoxy composition 0.03 X 10 m thick does not change the polymer condition. The high-energy surface can selectively sorb the epoxy resin, as a result of which the adhesive layer is improved by hardener, and the stoichiometry of the composition becomes disturbed. The polymer layer emiched in... 

Construction of transparent armors follows the principles that have been well established for their opaque counterparts. Armor against advanced threats has a typically structure as shown in Fig. 10.19 [165]. The front-face layer should be as hard as possible, in order to damage the projectiles in maximum range. Ideally, it should be harder than the projectile core. Currently, several hardened glasses or glass ceramics are being used. This layer is the weak point of present transparent... 

For the determination of the solid content 2 g of the sample (either resin or adhesive mix) were dried in a laboratory oven at 105 2°C, until a constant mass of the sample had been reached. The duration of this drying step was in the range of 24-48 h. The viscosity of the three UF resins and the adhesive mixes was determined by the Brookfield method. Gel time was determined at boiling water temperature in a glass tube with approximately 2 g of the resin (with addition of hardener as mentioned above) or the adhesive mix by gentle stirring. 

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