Network Stretching during Tensile Drawing of Polyethylene:  A Study Using X-ray Scattering and Microscopy

• Published in: Macromolecules Vol. 39; no. 1; pp. 268 - 273
• Main Authors: Hong, K, Strobl, G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 10-01-2006
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Structure, morphology and analysis; EVA; Polyethylene; Molecular orientation; Ethylene copolymer; X ray scattering; Amorphous orientation; Measurement method; Semicrystalline polymer; Experimental study; Uniaxial drawing
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma051726o

Because of the limitation that many semicrystalline polymers are not transparent, one cannot always study the network stress by optical methods. We suggest to use another tool in such a case. By measuring the azimuthal intensity distribution of the amorphous halo with wide-angle X-ray scattering experiments, one can determine the amorphous chain orientation induced in the strained network, which then results in the network stress. Experiments were carried out for a low-crystallinity polyethylene. They yield the relationships between the orientational order parameter associated with the halo, the birefringence produced by the amorphous chain parts, and the stress. The X-ray scattering results also show that the orientation of the amorphous segments under uniaxial drawing is comparable to the degree of orientation of the crystallites.