Dependence of the mechanical properties of a pullulan film on the preparation temperature.
The mechanical properties of pullulan films prepared at various temperatures were investigated. The films prepared at high temperatures (40 degrees C and 60 degrees C; H-films) did not show any clear plastic deformation in tensile test, indicating that they were brittle. In contrast, those prepared at low temperatures (4 degrees C, 13 degrees C, and 25 degrees C; L-films) showed such deformation. The latter films had higher values for both tensile strength and elastic modulus than the former, indicating that the L-films were stiffer and more flexible than the H-films. Stretching the L-films clearly showed a shear deformation band inclined at 45 degrees to the stretching direction, indicating that they were amorphous.
Kawahara
Makoto
M
Research Institute for Advanced Science and Technology (RIAST), Osaka Prefecture University, Sakai, Osaka 599-8570, Japan.
Mizutani
Kiyoshi
K
Suzuki
Shiho
S
Kitamura
Shinichi
S
Fukada
Harumi
H
Yui
Toshifumi
T
Ogawa
Kozo
K
D004548:Elasticity; D005936:Glucans / Q000737:chemistry*; D019563:Mechanics; D018583:Pliability; D013696:Temperature; D013718:Tensile Strength
D005936:Glucans; C009109:pullulan