DiMarzio and Gibbs

Another more recent a model to correlate Tg of plasticized systems was proposed by DiMarzio and Gibbs. They took into consideration the intramolecular interactions of polymer-plasticizer (but not the intermolecular interactions) via an iso-entropic model. In this model the glass transition occurs at a temperature at which the configurational entropy of the system becomes zero. Considering the effect of these interactions and based on thermodynamics, other models were developed, as those presented by Gordon et al and Couchman. " The expression obtained by Couchman for polymer blends or polymer-plasticizer mixtures has been applied successfiilly to plasticized PVC in a range of composi-... 

DiMarzio and Gibbs have derived equations which successfully describe the variation of with copolymer composition... 

The entropy theory of the glass transition was developed by Gibbs and DiMarzio and by Adams and Gibbs to describe polymeric systems. By mixing the polymer links with holes or missing sites on a lattice to account for thermal expansion as in a lattice gas model, they could determine the entropy of mixing and the configurational entropy of the polymer. They found a second-order transition at a temperature They then pointed... 

Over the past 30 years a number of theories have been developed to account for the variation in the glass transition temperature (Tg) of polymeric materials as a function of molecular weight (MW). Three of the most notable of these approaches have included the straight line technique of Fox and Flory and the statistical mechanical theories of Gibbs and Gibbs-DiMarzio (G-DM). Because of the universal applicability claimed for the latter approach, the G-DM theory has received considerable attention. " ... 

Some of the first theoretical work on DNA denaturation employed the LE model. Gibbs and DiMarzio and Zimm made use of the Jacobson and Stockmayer factor in melting curve calculations for one-component DNAs. The statistical weights s and [Pg.169]

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