Glassy-state transition

In the literature there is only one serious attempt to develop a detailed mechanistic model of free radical polymerization at high conversions (l. > ) This model after Cardenas and 0 Driscoll is discussed in some detail pointing out its important limitations. The present authors then describe the development of a semi-empirical model based on the free volume theory and show that this model adequately accounts for chain entanglements and glassy-state transition in bulk and solution polymerization of methyl methacrylate over wide ranges of temperature and solvent concentration. 

A comprehensive model which is based on the free-volume theory and which accounts for the effect of molecular weight and solvent on chain entanglements and glassy-state transition has been recently developed by Marten and Hamielec (7 ). This model accounts for diffusion-controlled termination and propagation... 

Mandelkern, L., G. M. Martin and F. A. Quinn Glassy state transition of Poly-(chlorotrifluoroethylene), Poly-(vinylidene fluoride) and their copolymers. J. Research Nat. Bur. Standards 58, 137—143 (1957). 

Perdon, A. Siebenmorgan, T.J. Mauronmoustakos, A. (2000). Glassy State Transition and Rice Drying Development of a Brown Rice State Diagram. Cereal Chemistry, Vol.77, No.6, pp. 708-713. 

Pig. 17. L< arithmic decrement (related to tan S and loss modulus) vs temperature for a fluorocarbon dibenzoxazole (174). After drying up to 200°C, the experiment was conducted at 200 —180 200°C AT/At = 1.5°C/min in a helium atmosphere. The Tg gives a sharp damping peak, whereas the secondary glassy state transitions, Tsec, are very broad. 

Perdon, A., Siebenmorgen, T. J., Mauromoustakos, A., 2000. Glassy state transition and rice drying Development of a brown rice state diagram. Cereal Chem. 77(6) 708-713. 

MAN Mandelkem, L. and Flory, P.J., Melting and glassy state transitions in cellulose esters and their mixtures with diluents, J. Amer. Chem. Soa, 73, 3206,1951. 

Mandelkern, L., Martin, G.M. and Quinn, FA. (1957) Glassy state transitions ofpoly-(chlorotrifluoroethylene), poly-(vinylidene fluoride), and their copolymers. /. Res. Natl. Bur. Stand., 58, 137 Fox, T.G. and Loshaek, S. (1955) Influence of molecular weight and degree of crosslinking on the specific volume and glass temperature of polymers.. 1. Polym. Sci., 15, 371. 

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