ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Rebound for study of thermal degradation of natural rubber

P. Králik

Slovak Technical University, Bratislava

Abstract: Thermal degradation of natural rubber samples prepd. from pale crepe soln. or from latex was studied by rebound according to Gordon and Grieveson (CA 54, 25948i) in the temp. interval of 80-150°. Samples were cast, and the solvent was evapd. and then extd. by cold MeOH and acetone. The min. sample thickness where the material of the support had no addnl. influence on the rebound was 1.7 mm. The initial max. rebound at a given temp. remains const. for a certain period, i.e., the induction period. The induction period being over, there is a sudden drop of rebound, indicating chain cleavages. The long and interwoven chains retain their elastic properties better than short and straight chains and therefore exhibit better thermal resistance. The activation energy of thermal degradation of natural extd. rubber was calcd. from the dependence of the length of induction period on the abs. temp. The activation energy for both types of samples is 21 ± kcal./mole, a value which is in good agreement with the results of other methods

Full paper in Portable Document Format: 177a461.pdf (in Slovak)

Chemical Papers 17 (7) 461–468 (1963)