Evidence Supports First Order Glass Transition
Chemical & Engineering News · 1963
145TH ACS NATIONAL MEETING Colloid and Surface Chemistry Evidence that the glass transition in polymers is first order comes from research work at the Massachusetts Institute of Technology. In studying emulsion polymers, Dr. Edward W. Merrill and David A. Gibbs have found a clearly defined plateau in their heating and cooling curves at the glass transition temperature. This plateau points to a first order transition. Most polymer chemists think of the glass transition (the point where polymers change from a glassy to a rubbery character) as second order. A glass transition would be first order if a thermodynamic property (such as specific volume) underwent a discontinuous change. Evidence for its second order nature has usually come from volume-temperature curves; these characteristically show an inflection without discontinuity at the glass transition temperature. However, the MIT research workers found work reported in the literature on volume-temperature relations which could offer a first ...