Orientation and phase content of high density polyethylene blown film
| Title |
Orientation and phase content of high density polyethylene blown film |
| Publication year |
2006 |
| Language |
English |
| Author |
Hinrichsen, Einar L. |
| Co-Authors |
Larsen, Åge - Tanem, B.S. - Follestad, Arild (Norner) - Helland, Irene (Norner) |
| Source |
COST P12 Conference Crystallisation and Structure Formation of Polymers, Mittelwihr Center France, 9-11 October 2006 |
| Abstract |
Poster - We present results from a study on HDPE films including materials of different molecular structure and produced with varying film draw-down. The study was motivated by the fact that density alone does not explain variations in film permeability. Further, increasing film line stress also has been reported to yield morphologies more open to permeants. In HDPE blown film high stress is known to lead to a row-nuclei morphology overgrown by radially orientated, no-twist lamellae with dominant c-axis MD orientation. These structures have been referred to as Keller-Machin 2 morphology and the orientation of the lamellae in this case could result in lower tortuosity of the diffusion path. The published results may have been based on films produced using increased draw-down to decrease the film thickness, thus possibly altering crystalline orientation. A row-nuclei structure is detected by AFM. More details on the orientation are obtained from IR spectroscopy - IR dichroic ratios as well as IR trichroism. Raman spectroscopy was applied to analyse the phase composition, giving the fractions of crystalline, amorphous and crystal-like interphase. Further details on orientation and lamellar structure were derived from SAXS. The results show the influence of material structure and film line stress on formation of row-nuclei and lamellar orientation. |