Material thickness, hydrolytic

Hydrolytic Stability. The polymers exhibited not only thermal oxidative stability, but also good hydrolytic stability. The hydrolytic stabilities of these polymers in the form of films and varnished wire were evaluated in water and aqueous base. The electrical resistance of th<=ge films ( 0 1.5 mm, 0.035-0.040 mm thick) in boiling water was 10 ohms. After treating in water at 200 C for 30 hours, the electrical resistances and weights of PPT (I)-PPT (V) remained essentially unchanged whereas the film of poly-imide suffered a 9.43% weight loss and failed to be an insulating material under the same condition. In order to make further observation on hydrolytic stability, a varnished wire was made by... 

The new polyurethanes were subjected to tests to assay their stability to hydrolytic and oxidative conditions. This involved immersing 1 mm thick dumbbell-shaped specimens separately in water, 2 M HCl, 5 M NaOH, 25% hydrogen peroxide, and sodium hypochlorite solution (4% available Clj) for 24 h at 100 °C. Dumbbells of the polyurethanes were also subjected to water at 120 C for 24 h. The decrease in fail stress relative to the untreated material was used to judge stability. 

The interphase is a three-dimensional (3-D) layer in the immediate vicinity of filler surface, possessing physical properties different from the two main phases or components in a composite (i.e., matrix and filler). For the purpose of this chapter, the term interphase is limited to the layers introduced on the filler surface intentionally in a controlled maimer—engineered interphase layers (EIL). In these layers, a gradient of chemical composition can also exist as well as a gradient of physical properties. The pivotal problem is therefore a definition and an evaluation of an interphase thickness and its properties, namely, stiffness and fracture toughness. Interphase behavior plays a paramount role in the ability to transfer loads from the matrix to the reinforcements, hydrolytic stability of the material, and fracture behavior of a particulate composite. 

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