Polymer composites with functionalized nanoparticles are a growing group of materials whose properties can be controlled not only through the kind and size of nanomaterial but also via its functionalization. Surface functionalization of nanoparticles enables their chemical bonding and helps to increase their compatibility with polymer matrix, as well as limits the undesired aggregation effects. Although numerous structure-processing-properties and physicochemical relationships in polymer composites with functionalized nanoparticles have been determined, there is still a need to investigate how the presence of nanoscale fillers influences the polymer nanocomposite fabrication route and final characteristics. It can be expected that recent developments in computational tools and modeling/simulation approaches, as well as progress in supramolecular and interface chemistry, will contribute to the better understanding of next-generation multifunctional nanocomposite materials with advanced physical properties. Moreover, future developments will need to address the recycling issues of functionalized nanoparticles and composites made therefrom, with special attention paid to health and environmental safety issues.
This chapter is intended as an overview of the recent research on the use of functionalized layered silicates, dispersed at the nanometer scale in polymeric matrices, for improving composite properties, such as mechanical and barrier properties. Clay-containing polymer nanocomposites have received considerable attention as they are used in a wide range of applications in various fields including food packaging, automotive, building applications, and many others. The desired properties of the nanocomposites can only be achieved with good dispersion of nanofiller in the polymer matrix, which is difficult to achieve because of their large specific surface area. The clay nanoparticles also have improved interfacial interaction between the nanoparticles and the polymer matrix. Layered silicates functionalization by onium salts is an efficient method to increase the space gallery distance and to increase the degree of hydrophobicity. Synthesis, surface functionalization, and structure–property relationships, as well as the barrier properties and aging/flammability behavior of clay-containing polymer nanocomposites are discussed in this chapter.
Modification of organo-montmorillonite with disodium H-phosphonate to develop flame retarded polyamide 6 nanocompositesPublished: 01 April 2017 by Elsevier BV in Applied Clay Science
Polymer nanocomposites attract large scientific and technological interest because of their considerably improved properties as compared to the conventional composites. This chapter starts by describing the various polyhedral oligomeric silsesquioxanes (POSS) particles available at laboratory or industrial scale. It explores the main processing methods of polyolefin, polyamide, polyurethane, and other polymer matrices such as melt blending, extrusion, injection molding, and compression molding. Copolymerization, grafting, and blending are useful methods yielding polymer-POSS multifunctional hybrid materials with intermediate properties between those of the organic polymers and of ceramics. The chapter focuses on polymer/POSS composites processing, rheology, and interactions between polymer matrix and filler. Investigation of the rheological properties in the molten state is fundamentally important to understand the processability and structure-property relationships of polymer composite systems. There are several key challenges encountered in preparing POSS-containing polymer nanocomposites, including tendency to aggregation of silsequioxane nanoparticles and expensive large-scale production.
Highlights•Novel recycling method for PP/MMT nanocomposites by pyrolysis was elaborated.•PP/OMMT nanocomposites were prepared by melt intercalation.•The pyrolysis process was carried out at 600 °C.•XRD patterns confirm that crystalline structure of pyrolysed MMT was basically kept.•Composites with pyrolysed MMT exhibit mechanical properties similar to those with pristine MMT. AbstractThe recycling of polymer/montmorillonite (MMT) nanocomposites, upon the end of their life cycle, has attracted so far less attention than its production. In this work, polypropylene/organophilized montmorillonite (PP/OMMT) nanocomposites were prepared by melt blending and then pyrolysed to produce pyrolysed filler which can be useful to fabricate new composites. XRD and SEM methods were employed to investigate the structure and morphology of the PP materials, as well as the pyrolysed OMMT. We show that OMMT, a thermal cracking catalyst, influences pyrolysis products distribution, promoting formation of light hydrocarbons instead of wax-like olefins. The pyrolysate obtained has been confirmed to be re-usable as filler in PP composites which showed mechanical properties similar to nanocomposites containing pristine montmorillonite.
Optimization and Scaling up of the Fabrication Process of Polymer Nanocomposites: Polyamide-6/Montmorillonite Case StudyPublished: 30 November 2013 by Springer Nature in Tropical Natural Fibre Composites
Although polyamide (PA) nanocomposites reinforced with montmorillonite (MMT) are processed for more than two decades, the primary technological problem related to optimization of processing conditions to fully exploit properties of these nanomaterials has still to be addressed. The processing of polymer nanocomposites by melt intercalation consists, in principle, of the following stages: preparation and drying of raw materials, preparation of a premix masterbatch, dosing the premix masterbatch into a feeding zone, heating and melting the polyamide-based matrix, an extrusion of a fluid composition followed by a set of auxiliary operations. The process of obtaining polyamide nanocomposites with the desired properties depends on numerous processing parameters that, when varied, affect the quality of manufactured products. Therefore, in this chapter techniques for obtaining polyamide-6/montmorillonite nanocomposites (PA6/MMT NCs), are presented along with discussion of the optimization process for the preparation of PA nanocomposites. Important technological problems arising during the processing are discussed in this chapter, as well as present issues which need to be addressed in scaling up the production from laboratory to industrial scale.