INVESTIGADORES
BERNAL Celina Raquel
artículos
Título:
Deformation and fracture behaviour of polypropylene-ethylene vinyl alcohol blends compatibilized with ionomer Zn2+
Autor/es:
M. MONTOYA, M.J. ABAD, L. BARRAL LOSADA AND C. BERNAL
Revista:
JOURNAL OF APPLIED POLYMER SCIENCE
Editorial:
Wiley Interscience
Referencias:
Año: 2005 vol. 98 p. 1271 - 1279
ISSN:
0021-8995
Resumen:
This work investigated the deformation and
fracture behavior of polypropyleneethylene vinyl alcohol
(PP/EVOH) blends compatibilized with ionomer Zn2. Uniaxial
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
2. Uniaxial
tensile tests and quasistatic fracture experiments were
performed for neat PP and for 10 and 20 wt % EVOH blends
with different ionomer contents. The addition of EVOH
copolymer to PP led to an increase in the Youngs modulus
whereas the yield strength was decreased with the EVOH
content as a consequence of the higher stiffness of EVOH
and the poor interfacial adhesion between PP and EVOH,
respectively. Furthermore, the incorporation of EVOH into
PP promoted stable crack growth. Neat PP displayed nonlinear
load-displacement behavior with some amount of
slow crack growth preceding unstable brittle fracture,
whereas most PP/EVOH blends exhibited pseudostable
fracture characterized by slow crack growth that could not
be externally controlled. All blends exhibited lower resistance
to crack initiation than PP but the fracture propagation
resistance was significantly improved. For 10 wt % EVOH
blends, the resistance to crack initiation was roughly constant
with the ionomer content up to 5%, then it increased
with the further addition of compatibilizer. Conversely, for
20 wt % EVOH blends, the resistance to crack initiation
appeared to be independent of the ionomer content. The
better resistance to crack initiation exhibited by the 10 wt %
EVOH blends could be attributed to a higher level of compatibilization
in these blends. By contrast, 20 wt % EVOH
blends with 2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
2% ionomer content showed completely stable
crack growth. In addition, JR curves and valid plane strain
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
fracture toughness values for these blends could also be
determined
JR curves and valid plane strain
fracture toughness values for these blends could also be
determined