Fine Structure and Nucleation Mechanism of Extended Chain Crystal of Polyethylene

The fracture surfaces of extended chain crystal were observed with 100 kV electron microscope for samples obtained from linear polyethylene (A4=64,000) by isothermal crystallization under elevated pressure. Some fracture surfaces were prepared after uniaxial compression was given to the samples. The obtained results were as follows: the samples were irregular aggregation of block-bands and the bands consisted of the bundles of extended-chain crystal strings (rod-like crystals of 300-500 A diameters). Some of the strings penetrated into adjacent block-bands. These crystal strings were considered to be the nuclei of extended chain crystal which were precipitated from extended chain molecules directly