INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
capítulos de libros
Título:
PHASE SEPARATION OF PMMA-MODIFIED VINYLESTER
Autor/es:
WALTER F. SCHROEDER, JULIO BORRAJO, MIRTA I. ARANGUREN
Libro:
Thermoplastic and Thermosetting Polymers and Composites
Editorial:
NOVA Publishers Inc
Referencias:
Lugar: New York; Año: 2010; p. 1 - 23
Resumen:
In this Chapter, the initial miscibility, the developed morphologies, and the final
properties of styrene(St)/vinyl-ester(VE) thermosets modified with poly(methyl
methacrylate) (PMMA) are discussed. The effect of changing the molecular weight and
the polydispersity of the VE oligomer and the PMMA modifier are presented. Firstly, the
miscibility of binary and ternary physical mixtures of the components involved in the
different studied formulations is analyzed. The experimental liquid-liquid equilibrium
curves (e.g. cloud-point curves) allow computing the binary interaction parameters, ÷, in
the framework of the Flory-Huggins theory for polydisperse systems. These parameters
are used to model the quasiternary phase diagram that represents the initial
thermodynamic state of each particular system. This miscibility behavior originates quite
different morphologies in the cured materials, generated by polymerization induced phase
separation (PIPS) mechanism. For instance, dispersion of thermoplastic-rich particles in a
thermoset-rich matrix, cocontinuous structure, dispersion of thermoset-rich particles in a
thermoplastic-rich matrix (phase-inverted structure), or typical macrophase morphology
characterized by droplets-like domains with secondary phase separation inside the
droplets can be observed. These morphological structures are directly related to the
thermal and mechanical properties, as well as the volume shrinkage of the final systems.
The evaluation of the dynamic mechanical behavior, flexural modulus, compressive yield
stress, and fracture toughness shows that the addition of PMMA increases the fracture
resistance without significantly compromising the thermal or mechanical properties of the
the framework of the Flory-Huggins theory for polydisperse systems. These parameters
are used to model the quasiternary phase diagram that represents the initial
thermodynamic state of each particular system. This miscibility behavior originates quite
different morphologies in the cured materials, generated by polymerization induced phase
separation (PIPS) mechanism. For instance, dispersion of thermoplastic-rich particles in a
thermoset-rich matrix, cocontinuous structure, dispersion of thermoset-rich particles in a
thermoplastic-rich matrix (phase-inverted structure), or typical macrophase morphology
characterized by droplets-like domains with secondary phase separation inside the
droplets can be observed. These morphological structures are directly related to the
thermal and mechanical properties, as well as the volume shrinkage of the final systems.
The evaluation of the dynamic mechanical behavior, flexural modulus, compressive yield
stress, and fracture toughness shows that the addition of PMMA increases the fracture
resistance without significantly compromising the thermal or mechanical properties of the
÷, in
the framework of the Flory-Huggins theory for polydisperse systems. These parameters
are used to model the quasiternary phase diagram that represents the initial
thermodynamic state of each particular system. This miscibility behavior originates quite
different morphologies in the cured materials, generated by polymerization induced phase
separation (PIPS) mechanism. For instance, dispersion of thermoplastic-rich particles in a
thermoset-rich matrix, cocontinuous structure, dispersion of thermoset-rich particles in a
thermoplastic-rich matrix (phase-inverted structure), or typical macrophase morphology
characterized by droplets-like domains with secondary phase separation inside the
droplets can be observed. These morphological structures are directly related to the
thermal and mechanical properties, as well as the volume shrinkage of the final systems.
The evaluation of the dynamic mechanical behavior, flexural modulus, compressive yield
stress, and fracture toughness shows that the addition of PMMA increases the fracture
resistance without significantly compromising the thermal or mechanical properties of the