Improving the Thermal Stability of Polystyrene by Friedel-Crafts Chemistry
Polymer Degradation and Stability
The alkylation of polystyrene with a difunctional alkylating agent, such as 1,4-benzenedimethanol, proceeds in the presence of a zeolite catalyst to give a significant amount of cross-linked, and thermally stable, polymer. Various zeolites are used as catalysts; there is apparently some relationship between the type of zeolite and its catalytic activity. The extent of cross-linking depends upon temperature. With some zeolites there is no reaction below 300 °C while others will permit reaction below 300 °C. A significant fraction of the polymer does not volatilize at 800 °C in a nitrogen atmosphere.