Co-continuous structures can be regarded as the coexistence of at least two continuous structures within the same volume. Blends with co-continuous structures may combine the properties of both components in a favorable way, for example, mechanical moduli. This review article deals with the identification, characterization, and properties of co-continuous structures as well as with the development of co-continuous structures during the melt blending process. Co-continuous structures usually can be formed within a composition region about the phase inversion composition, which mainly depends on the viscosity ratio. On the other hand, co-continuous structures can be found independent of composition as intermediate stages during the initial state of morphology development and during phase inversion process in blends in which the component finally forming the dispersed phase forms the matrix in early mixing states. In addition, even at low volume fractions of one component, stable co-continuous morph...

Formation of Co-continuous Structures in Melt-Mixed Immiscible Polymer Blends

Selective Localization of Nanofillers: Effect on Morphology and Crystallization of PLA/PCL Blends

Phase behavior and its viscoelastic response of polylactide/poly(ε-caprolactone) blend

In order to improve the properties of plasticized wheat starch (PWS) and to conserve its final biodegradability, PWS can be blended with biodegradable polyesters [polyesteramide, poly(e-caprolactone), poly(lactic acid), poly(butylene succinate adipate) and poly(butylene adipate terephthalate)] which exhibit variable polar characteristics. This paper is focused on the analysis of the compatibility of these blends which vary according to their formulation. To understand the lack of affinity between the different phases, interface adhesion has been investigated by contact angle measurements to obtain the work of adhesion. From these determinations a forecast approach has been developed to predict blend compatibility. Blend structures were obtained by scanning electron microscopy observations. Blends show either a dispersed structure or a co-continuous morphology. Percolation thresholds (co-continuity) and full continuity regions were determined thanks to a method based on solvent extraction. Finally, rheological investigations have been carried out on the different biodegradable polymers to understand better the blend structure formation during the process. Copyright © 2004 Society of Chemical Industry

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Starch-based biodegradable blends: morphology and interface properties

Biodegradable poly(butylene succinate)/polylactide (PBS/PLA) blends with various blending ratios were prepared by melt mixing for morphological and rheological studies. Dynamic rheological measurements were performed on the blend systems and the viscoelastic responses were analyzed with several emulsion models. The results show that the PBS/PLA is an immiscible blend system with very narrow cocontinuous region and high percolation threshold. The phase inversion point could be precisely predicted by the small-amplitude oscillatory shear (SAOS) response. The Palierne model gave a better description of the viscoelastic response of PBS/PLA blends than that of the Gramespacher and Meissner (G-M) model. In addition, the interfacial tension between the two polymers was measured by several techniques, such as surface property characterizations, deformed drop retraction, and rheological approaches. The differences observed by these various methodologies were then further explored. Moreover, the melting and crystal...

Nicolas Marin

Papers

Co-continuous morphology development in partially miscible PMMA/PC blends