Temperature effects adhesives

Rate and Temperature Effects. Adhesion of a soft crosslinked polymer to a rigid substrate is found to increase markedly as the rate of debonding is increased. An example is shown in Fig. 31. The strength also increases as the temperature is reduced, Fig. 31. Thus,... 

For example, poly(vinyl alcohol) (PVOH) finds application as an effective adhesive for paper products such as the old-fashioned postage stamps or envelopes. Licking the stamp or envelope flap causes the adhesive to become sticky because water plasticizes the PVOH and lowers the Tg below room temperature. On pressing the stamp to a piece of paper, the polymer chains can entangle and hydrogen bond with the cellulose in the paper. As the water... 

Effect of Moisture and Temperature on Adhesive Bonds, Tests for D 1151... 

Only a small amount of liquid, about a hundred molecule thick layer, is sufficient for the adhesion contact of sub-micron diameter particles ( 8). In the case of a volatile liquid, the equilibrium thickness of the film, and thus the adhesion, varies with partial pressure of the vapour in the surrounding atmosphere. When evaporation from a liquid film occurs, as a result of increased temperature, the adhesion first rises to a maximum value due to the meniscus effect but it breaks down as the film thickness is reduced to molecular dimensions. However, before the break-down of the surface tension chemical and mechanical bonds may develop between the deposited ash and boiler tube surface. 

Figure 18.3 Effect of maleic anhydride grafted onto HDPE on Conditional growth of adhesion strength (A ) for joints of PA6/HDPE-g-MAH temperature of adhesion contact is 220°C.

The effect of water immersion (57°C) on the torsional shear strength of Versamid 140 (O) and DETA ( ) room temperature cured adhesive joints. 

Table 6.1 Effect of modulus, expansion coefficient, and temperature on adhesive stress ... 

Figure 10 Effect of temperature on adhesion hysteresis (after Ref. 79).

Table 6.1. Effect of Modulus, Expansion Coefficient, and Temperature on Adhesive Stress ... 

The practical aspect of the high Tg polymeric additive concept for adhesion becomes apparent when one considers certain temperature effects associated with a multi-lamp UV-radiation curable coating processing unit. If a... 

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