Diol Structure on Thermal Stability of the PU Elastomer Molar Ratios

Influence of the Diol Structure on Thermal Stability of the PU Elastomer Molar Ratios 1 2 1 

The way in which the chemical structure of the various chain extenders of Table 3.16 influences the thermal stability of polyurethane elastomers based on the molecule Capa 225/CHDI/chain extender in the molar ratio 1 2 1, respectively, is given in the following figures and tables. For example, Fig. 3.7 shows the dynamic mechanical thermal properties of a series of the polyurethane elastomers in which the variable is the chain extender. The temperature at which the value of the storage modulus (log E ) changes significantly is considered to indicate the limit of thermal stability of the polyurethane elastomers. 

From this the following maximum thermal stability values are implied  

To these results some general rules can be applied it is shown that the para isomer chain extender (Quinol) gives a PU of higher thermal stability than its ortho isomer (catechol) 

Similarly for PUs based on naphthalene-type diol chain extenders the thermal stability falls in the following order  

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