Substituted polyacetylenes suffer from important degradation in contact with air at moderately high temperatures, making them useless since some mechanical properties are lost.
Immersion into extreme alkaline pH solutions, however, seems to cause severe hydrolysis of the peptide chains to an extent that the fibrilar configuration is disrupted and the mechanical properties are lost.
It has been reported that MTA can have different physical and mechanical properties and lose consistency in the presence of excess liquid, which can occur even at the proportion recommended by manufacturers [ 2] and the resultant mix can lack adequate viscosity [ 3].
The metals lose mechanical properties at melting point.
Polyimide membrane (Ia − 90), for example, did not lose mechanical properties after being soaked in boiling water for 1000 h, while its proton conductivity was still at a high level (compared to that of Nafion 117).
Finally, it is important to note that Ca2+ cross-linked alginate hydrogels lose mechanical properties over time in vitro, presumably due to slow loss of crosslinking Ca2+ ions into the culture medium [ 16, 39].
The results showed pins with greater crystallinity lost their mechanical properties more quickly, although an increase in the degree of crystallinity for both types of pins was observed over time.
Collagen, by contrast, is decomposed in a neutral milieu, but loses its mechanical properties during the digesting process, if not appropriately stabilized, e.g. by cross-linking of the individual polymer strains [4].
However, in the physiological environment, they are corroded rapidly and thus lose the mechanical properties [ 19].
Third, composite bows can be kept strung for long periods of time without losing their mechanical properties.
