TIT# Extruded blend films of poly(vinyl alcohol) and polyolefins. Common and
     hard-elastic nanostructure evolution in the polyolefin during straining
     as monitored by SAXS
AUT# Stribeck, Norbert, Zeinolebadi, Ahmad; Fakirov, Stoyko; Bhattacharyya, Debes;
     Botta, Stephan;
SOU# Sci. Technol. Adv. Mater. (2013), 14, 035006
LOC# xv140
CLA#
COM#
APP#
MAT#
ABS# Straining of PVA/PE and PVA/PP blends (70:30) is monitored by small-angle
     X-ray scattering (SAXS). Sheet-extruded films with different predraw
     ratio are investigated. The discrete SAXS of predrawn samples originates
     from polyolefin nanofibrils inside of polyolefin microfibrils immersed
     in a PVA matrix. PE nanofibrils deform less than the macroscopic strain
     without volume change. PP nanofibrils experience the macroscopic strain.
     They lengthen but their diameter does not decrease. This is explained by
     strain-induced crystallization of PP from an amorphous depletion shell
     around the core of the nanofibril. The undrawn PVA/PE film exhibits
     isotropic semicrystalline nanostructure. Undrawn PVA/PP holds PP droplets
     containing oriented stacks of semicrystalline PP like neat precursors of
     hard-elastic thermoplasts. Respective predrawn films are softer than the
     undrawn material, indicating conversion into the hard-elastic state.
     Embedding of the polyolefin significantly retards neck formation. The
     polyolefin microfibrils can easily be extracted from the water-soluble
     matrix.