Origin of Additional Mechanical Transitions in Multicomponent Polymeric Materials

Abstract

The viscoelastic properties of several multicomponent materials (including both particulate multipolymeric materials and multilayer polymer blends) were investigated in relation to their microstructures and phase-property dependencies. Theoretical considerations based on mechanical modeling were used to explore the origin of additional mechanical transitions in experimental viscoelastic spectra. The major part of this work was devoted to particulate multicomponent systems, and especially to the further exploration of the characteristics of the so-called micromechanical transition (MMT). Although such an additional phenomenon is clearly explained as a result of a specific interphase, our investigation also provides evidence that the occurrence of a MMT in dynamic mechanical spectra reflects the contribution of the geometrical arrangement into phases of a set of properties of the pure components, rather than a molecular relaxational process within the interfacial area. Finally, on the basis of an equivalent approach, the influence of the geometrical arrangement of phases on the viscoelastic response of multilayer polymer blends was pointed out as a relevant argument to justify the existence of "spurious" additional damping peaks in some experimental dynamic mechanical spectra reported in the literature.

Effects of particle size, particle/matrix interface adhesion and particle loading on mechanical properties of particulate–polymer composites

“…In addition, Christensen and Lo's three-phase model [126], Mori-Tanaka method, self-consistent method, Halpin and Kardos' model [127] of micromechanics can also be extended to account for the interface effect by including an interphase region between the matrix and particles [128,129]. For instance, Colombini et al [130,131] used the self-consistent scheme based on a ''particle-interphase-matrix" three-phase unit cell model to study the influence of the particle size and shape on the mechanical properties of bimodal hard/soft latex blends. They found that the smaller the size of the hard particles, the better the mechanical enhancement of the mechanical film properties.…”

Using a pattern-based homogenization scheme for modeling the linear viscoelasticity of nano-reinforced polymers with an interphase

“…This model is based on a 3-phase spherical inclusion embedded in the homogeneous equivalent medium and has been given with full details by Maurer (1990), with applications to interphases in viscoelastic materials by Maurer (1986), Schaeffer et al (1993), Eklind and Maurer (1996), Colombini et al (1999), Reynaud et al (2001), Colombini et al (2001), Colombini and Maurer (2002), among others. A derivation of the same model leading to different equations, has also been proposed by Hashin and Monteiro (2002), for an interphase problem in elastic materials.…”

Mechanical properties of high elastic polymer matrix composites filled with rigid particles: Nanoscale consideration of the interfacial problem

“…Usually the interphase layer is simulated by the same continuous media, differing from the matrix and inclusions only by mechanical characteristics, and described by the same equations of the theory of elasticity [4][5][6]. Particularly, the numerical method for description of viscoelastic properties of composites with consideration of the peculiarities of the interphase layer was proposed in Ref.…”

“…Particularly, the numerical method for description of viscoelastic properties of composites with consideration of the peculiarities of the interphase layer was proposed in Ref. [6]. Herewith, an ordinary method of self-coordination [7] is extended for the case of three-component media, namely, matrix, filler and interphase layer.…”

“…In [8,9] the interphase layer is considered as the same polymer medium but differing from the matrix in mechanical characteristics. Such approaches are evidently important and, probably, make sense in particular problems, but in fact the real interphase layers cannot be simulated in this way, as was done in previous work [6,8,9].…”