Abbau von aus der schmelze kristallisiertem polyäthylen durch salpetersäure

Melt crystallized linear and branched polyethylenes with crystallinities varying between α = 0.44 and α = 0.94 have been treated with nitric acid, which attacks and destroys the amorphous regions. The influence of acid concentration, reaction temperature, and reaction time has been studied. Investigations of melting behaviour, density, weight loss, X-ray crystallinity, long period, molecular weight and molecular weight distribution, and electron microscopic observations are discussed as functions of the structure and reaction parameters.