Hot-water-soak test

Figure 10.5 shows the data obtained on an epoxy-nitrile film adhesive on 5052-H34 aluminum alloy after immersion in hot water for 50, 100, 300, 500, and 1000 hours. This test is very useful because it permits a large number of adhesive-bonded specimens with different adhesives, adher-ends, and surface pretreatments to be tested at the same time with a relatively small investment in man hours and equipment. Figure 10.6 shows a comparison of the stressed-durability data and unstressed hot-water-soak data on the same epoxy-nitrile film adhesive, using 2024-T3 aluminum alloy. Note the parallelism of the plots. The curve in the lower left was obtained when lap-shear specimens were subjected to various levels of stress and then exposed to an environment of 60°C and 95% RH until failure. The failure time is plotted as a log function. The curve in the upper right portion is a plot of the data when the same types of lap-shear specimens were subjected to 60°C water for specified periods of time and then tested for their residual strength. In the first case, failure time was recorded. In the latter case, residual strength was determined. The same type of data is obtained with both curves. ... 

Borosilicate glass ampoules of 100 mL were used for the preparation of the reference solutions they were washed with hot water, rinsed with ultrapure water, soaked during 24 h with 5% nitric acid solution and rinsed again with ultrapure water. The ampoules were then stoppered and sterilised at 180°C during 45 min. Blank tests performed in water in contact during 7 days with the ampoules did not reveal any chemical or microbiological contamination. The ampoules were not conditioned with the solutions they would contain in order to avoid bacterial contamination [14]. 

How to determine sufficient durability of wood bonds is still of great concern. ASTM D 2559 has been considered the ultimate test, but there has been little discussion of forces on the bondline during this test and how representative they are of those experienced in the actual application. The test involves cycles of rapid water soaking by vacuum-pressure soaks followed by rapid drying in a hot oven. Not surprisingly, this test causes considerable distortion and fracturing of the wood itself because the dimensional changes are so rapid that the wood does not... 

In his test, a thin film of adhesive on a glass microscope slide or a metal coupon is cured and soaked in hot water until the film can be loosened with a razor blade. There is usually a sharp transition between samples that exhibited cohesive failure in the polymer and those which exhibited more of an interfacial failure. Since the diffusion of water into the interface is very rapid in this test, the time to failure is dependent only on interfacial properties and may differ dramatically between unmodified epoxy bonds and epoxy bonds primed with an appropriate silane coupling agent. The time to debond in the hot water for various silane primers differed by several thousandfold when used with a given epoxy. In parallel tests, a thick film of epoxy adhesive on nonsilaned aluminum coupon showed about the same degree of failure after 2h in 70°C water as a silaned joint exhibited after more than 150 days (3600 h) under the same conditions. 

Plastic models of female newts were made from a plaster of Paris cast of a dead female newt. Models were molded from worm plastic with colorant (Cabela s, Sidney, Nebraska). Models were colored off-white or with brown and orange to imitate female T. granulosa. Models were washed with hot, soapy water, soaked overnight and rinsed 5 times after each test, then randomly redistributed to different scent groups on subsequent tests. Precautions, such as handling models with latex gloves, were taken to avoid odor contamination. 

---