Rheological, Mechanical and Morphological Characterization of Fillers in the Nautical Field: The Role of Dispersing Agents on Composite Materials

Abstract

Coatings have a fundamental role in covering the external surface of yachts by acting both as protective and aesthetic layers. In particular, fillers represent the essential layer from the point of view of mechanical properties and consist of a polymeric matrix, different extenders and additives, and dispersing agents, with the latter having the role to provide good extender-matrix compatibility. In the present work, the effects of dispersing agents with an ionic or steric action on the interactions between hollow glass microspheres and an epoxy-polyamide resin are evaluated. Un-crosslinked filler materials are studied via rheological tests, whereas the mechanical and morphological properties of the crosslinked samples are assessed. The results clearly indicate that steric dispersing agents provide a much greater compatibility effect compared to ionic ones, owing to their steric hindrance capability, thus leading to better-performing filler materials with a less-marked Payne effect, which is here proved to be an efficient tool to provide information concerning the extent of component interactions in nautical fillers. To the best of our knowledge, this work represents the first attempt to deeply understand the role of dispersing agents, which are until now empirically used in the preparation of fillers.

Investigation of the Mechanical and Dynamic-Mechanical Properties of Electrospun Polyvinylpyrrolidone Membranes: A Design of Experiment Approach

“…Figure 4 shows the obtained results for the prepared membranes alongside the nanofiber collection direction (i.e., 0°), with a similar behaviour observed perpendicularly (i.e., 90°). In the investigated frequency range, the samples showed a nearly constant trend of the extensional storage modulus E', as well as a slight decrease of the extensional loss modulus E" (data not shown), which is consistent with their predominantly elastic nature and localizes their response within the rubbery elastic plateau region [59][60][61]. The DMA spectrum of polymers can be indeed divided into several portions depending on the material properties.…”

Effect of Technological Waste on Rheological Properties of the Polymer Composite

“…The rheological characteristics are closely related to the technological aspects of polymer processing, because most of the processing technologies of polymer materials are based on their processing in the melt, where the polymer flow or its deformation occurs in the melt or in the solid state. [1], [2] In order to establish the processing properties of polymeric materials, it is necessary to know the properties that affect such materials' susceptibility to physical and chemical changes in structure and the properties demonstrating themselves in course of processing polymeric materials. The processability thus defined is of great practical importance, and knowledge of the same is applied to the polymeric material processing.…”

Organic–Inorganic Hybrid Materials

“…The effect of the dispersing agents with an ionic or steric action on the interactions between hollow glass microspheres and an epoxy-polyamide resin on composite materials for nautical applications are studied by Dodero, Vicini, and colleagues [ 13 ]. The composites are evaluated by means of the rheology of the un-crosslinked material as well as mechanical and morphological properties of the crosslinked composites.…”