In an effort to investigate the morphology of biodegradable films, the comb
ination of differential scanning calorimetry, scanning electron microscopy,
and Fourier transform infrared polarization spectroscopy methods are used.
The methods enable one to examine the structural and morphological peculia
rities of extruded blend compositions on the base of low-density polyethyle
ne (LDPE) and poly(3-hydroxybutyrate) (PHB) at concentrations of the latter
ranges from 0 to 32 wt%. The blend components are thermodynamically incomp
atible and form the proper morphological elements with good visible interfa
ces between the disperse phase (PHB) and the continuous matrix LDPE. For fi
lm extrusion, blend components affect each other, as is seen by the crystal
linity drop for both PHB and LDPE. The dichroism measurements show that the
axes of LDPE and PHB molecules are presumably located at right angles, the
rewith the largest axes of the PHB crystallites are oriented along the extr
usion direction. The matrices at all blend ratios, besides 32 wt% compositi
on, are reinforced by alternative bandlike and cylinderlike fibriles of PHB
. The architecture of such morphological elements is carefully studied by t
he SEM method.