Intercrystalline links in polyethylene crystallized from the melt

Abstract

Abstract Intercrystalline links in polyethylene have been revealed by crystallizing from the melt mixtures of fractionated polymer and the linear hydrocarbon n ‐C 32 H 66 , the latter constituent being removed later by washing at room temperature in an organic solvent. These fibrous links measure up to 15,000 A. in length and are 30–300 A. in thickness. Molecular chains are oriented parallel to the lengths of the links, and apparently nucleate on tie molecules formed by the simultaneous crystallization of different parts of the same molecule on the surfaces of different, and often widely separated, crystals. The maximum length of the links found in a given polymer varies as the square root of molecular weight, and there are indications that molecules in the melt are much more extended than is predicted by conventional configurational statistics. The links are under tension and presumably exert a significant influence on physical properties.