Mechanical properties materials incorporated into polymers

Carbon-based polymer nano composites represent an interesting type of advanced materials with structural characteristics that allow them to be applied in a variety of fields. Functionalization of carbon nanomaterials provides homogeneous dispersion and strong interfacial interaction when they are incorporated into polymer matrices. These features confer superior properties to the polymer nanocomposites. This chapter focuses on nanodiamonds, carbon nanotubes and graphene due to their importance as reinforcement fillers in polymer nanocomposites. The most common methods of synthesis and functionalization of these carbon nanomaterials are explained and different techniques of nanocomposite preparation are briefly described. The performance achieved in polymers by the introduction of carbon nanofillers in the mechanical and tribological properties is highlighted, and the hardness and scratching behavior of the nanocomposites are also discussed. 

Other materials that have been incorporated into polymers to modify mechanical and other properties include calcium sulfate in styrene-butadiene rubber [174-178], barium sulfate in polyethylene [179], barium sulfate in polypropylene [174], aluminum in epoxy resins [178], kaolinite-muscovite in polyvinyl chloride-polybutyl acrylate... 

Fillers alter the mechanical properties of the set polymer. Frequently the filler is used to increase strength and hardness. Sand and larger aggregate is used in building restoration (Lawrence et al., 2006). Weak fillers are incorporated into polymers to allow the set material to be reworked by drilling or sanding. These can be solid, e.g. talc and calcium carbonate, or hollow microspheres. 

In general, nanocomposites can be divided by their application into structural and functional ones (Gerasin et al. 2013). While the incorporation of NPs in structural nanocomposites enhances the mechanical properties processability of a polymer matrix, the desired characteristics of functional materials are based on the properties specific to NPs (such as quantum size effect in a semiconductor particle, the excitation of localized surface plasmons in metal particles, superparamagnetism of magnetic particles, etc.) combined with the properties of polymers. 

Nanopartides, which have at least one length scale on the order of nanometers, can come in a variety of shapes (e.g., spherical, platdet, or rod-like). A surge of interest in nanocomposites came when Toyota reported the first synthesis of exfoliated nylon-6-day nanocomposite materials that exhibited enhanced mechanical properties over traditional composites. Since then, a wide range of inorganic indusions have been incorporated into polymer materials, resulting in a plethora of material properties. ... 

Siloxane containing interpenetrating networks (IPN) have also been synthesized and some properties were reported 59,354 356>. However, they have not received much attention. Preparation and characterization of IPNs based on PDMS-polystyrene 354), PDMS-poly(methyl methacrylate) 354), polysiloxane-epoxy systems 355) and PDMS-polyurethane 356) were described. These materials all displayed two-phase morphologies, but only minor improvements were obtained over the physical and mechanical properties of the parent materials. This may be due to the difficulties encountered in controlling the structure and morphology of these IPN systems. Siloxane modified polyamide, polyester, polyolefin and various polyurethane based IPN materials are commercially available 59). Incorporation of siloxanes into these systems was reported to increase the hydrolytic stability, surface release, electrical properties of the base polymers and also to reduce the surface wear and friction due to the lubricating action of PDMS chains 59). 

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