UNJAMMING TRANSITION AND COLD FLOW OF POLYMER CHAINS

Jamming occurs when a system develops a yield stress - behaves as a solid - in a disordered state, and it governs the transition behavior of foams, emulsions, colloidal suspensions, pastes, granular media and molecular glasses. For polymer glasses, when the interchain proximity was enlarged, the weak interaction between polymer chains was decreased, and these loosely packed chains can flow solely by applying pressure at temperature 132 degrees below their calorimetric glass transition temperature, T-g, which means T-g decreased to a great extent in this progress. This phenomenon is connected to the concept "jamming", which suggests the generality of an idea that one can take polymer glasses through solid-to-liquid transition by thermalization, through temperature, or by a load. It is expected within the jamming picture that we could process polymers at lower temperature or even at room temperature.