Molecular, thermal, and morphological characterization of narrowly branched fractions of 1-octene linear low-density polyethylene. 3. Lamellar and spherulitic morphology

Abstract

The semicrystalline lamellar morphology, the crystalline phase, and the spherulitic structure of 1-octene linear low-density polyethylene (LLDPE) fractions with a narrow short chain branching distribution were studied. The average short chain branching content of the fractions studied increases from 2.9 to 28.2 branches per 1000 carbon atoms while the molecular weight M w concomitantly decreases from 2.7×10 5 to 1.9×10 4 . Characteristic morphological parameters include the number-average lamellar thickness, the thickness of the crystalline core and of the transition layers, the periodicity of the lamellar stacks, the unit cell dimensions of the crystalline phase, and the average radius of the spherulites