Retained solvents glass-transition temperatures

A glass is formed when certain liquids are cooled below a temperature known as the glass transition temperature. The molecules retain the structure of the liquid state at that temperature, but they are frozen in a motionless state. There is however no special ordering of the solvent molecules around a solute. 

Retained solvents may act as plasticizers (i.e., unless the solvent evaporates completely, the deposited resin may not have the same properties as the original solid in its pure state). Retained solvent lowers the glass-transition temperature. If the Tg of the mixture is at or below room temperature, rubbery behavior will result, and consolidant effectiveness will be reduced. Acryloid B72 seemed to retain solvent in films cast from acetone and toluene solutions and then air-dried (12). Further study showed that Acryloid B72 may retain measurable amounts of solvent even after 30 days at room temperature (16, 17). Results are shown in Table II. 

Table II. Glass-Transition Temperatures and Retained Solvent Concentrations of Cast Films ...

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