Cooling specimen preparation

The Cu-Sn specimens for experiments were prepared by sequential deposition of copper (560 nm) and tin (200 or 560 nm) films on quartz discs under vacuum. To prevent any reaction during the specimen preparation, a tin film was deposited after cooling the substrate with a copper film down to the liquid nitrogen temperature (for more detail, see Ref. 64). 

Specimens of each material were prepared under two very different molding conditions slow-cooled and quench-cooled. Hytrels 6355 and 5555 were compression-molded at 270°C quench-cooled specimens were then plunged into ice water whereas slow-cooled specimens were cooled to 200°C over 10 min and then cooled from 200°C to room temperature in about another 10 min. 

Uncured Tel-Tak specimens were prepared by cutting rubber sheeted out from a mill at about 1.4 mm (0.06 in) thick. They were then placed over a piece of square woven fabric and pressed between a sheet of mylar on the top and cellophane on the bottom in a mold for 5 minutes at 100 C. After cooling, specimens were cut from the fabric side to 0,25 in, X 2 in. Two rectangular specimens are required for each test. Each test piece is mounted in the Tel-Tak instrument perpendicular to the other in order to assure the same contact area for each test. 

Bucher et al. (1970) and Kayser (1970) independently reported that the stable low temperature phase of Yb is hep rather then fee. Tanuma et al. (1970) reexamined the de Haas-van Alphen effect and confirmed that Yb transforms to hep after a cooling cycle to 1.2 K. A specimen prepared in this way may be predominantly in the hep phase, but it inevitably contains some amount of the fee phase. To what extent this mixture of phases may affect the de Haas-van... 

The press is closed and a pressure of 0.34 MPa is applied and held for four minutes at 264°C. Pressure is increased to 1.72 MPa for one minute followed by an increase to 2.24 MPa, which is held for five minutes. At the end of this period, the assembly is removed and quenched in an ice water bath. The ferro plates should be removed, and the cooling of the chase and the sheet should be continued until the sheet has reached room temperature. The sheet then can be used for specimen preparation. 

Figure 10.17 Log G versus log G" plots for an ether-based MDI/BDO/POTM TPU specimen (a) the results in the heating process at various temperatures (°C) (O) 140, (A) 150, ( ) 160, (V) 170, (O) 180, and (O) 190, and (b) the results in the cooling process at various temperatures (°C) ( ) 190, (A) 180, ( ) 165, (T) 155, and ( ) 145. A single specimen prepared by injection molding at 180 C was employed for the entire experiment. (Reprinted from Yoon and Han, Macromolecules 33 2171. Copyright 2000, with permission from the American Chemical Society.)...

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