In Situ Preparation of Polyether Amine Functionalized MWCNT Nanofiller as Reinforcing Agents

In situ preparation of polyether amine functionalized cross-linked multiwalled carbon nanotube (MWCNT) nanofillers may improve the thermal and mechanical properties of the composites in which they are used as reinforcing agents. The reduction and functionalization of MWCNT using ethylenediamine in the presence of polyether amine produced stitched MWCNT's due to the presence of two amine (–NH2) functionalities on both sides of the polymer. Polyether amine was chosen to polymerize the carboxylated MWCNT due to its potential to form bonds with the amino groups and carboxyl groups of MWCNT which produces a resin used as polymeric matrix for nanocomposite materials. The attachment of the polyether amine (Jeffamine) groups was verified by TGA, FT-IR, XRD, SEM, and Raman spectroscopy. The temperature at which the curing enthalpy is maximum, observed by DSC, was shifted to higher values by adding functionalized MWCNT. SEM images show the polymer formation between MWCNT sheets. 1. Introduction Much attention has been given in recent works on carbon nanotubes (CNTs) either single wall carbon nanotubes (SWCNT) or multiwall carbon nanotubes (MWCNT) because of their small size and unique properties [1–3]. Thus these materials found potential uses mainly in engineering applications and biomedical devices [4–7]. There are two major drawbacks of the MWCNTs: the reactivity of their graphitic structure and the agglomeration affinity due to the large specific surface area. The potential of these new materials in composite materials can be fully explored when these disadvantages are solved, essentially by functionalization. Chemical functionalization of CNTs is very important in different applications. The attachment of functional groups or aliphatic carbon chains to the nanotubes can boost the solubility of nanotubes in organic solvents and compatibilize them with the polymeric matrix [8]. It is well known from many studies that the presence of different purposeful groups is the starting point for binding a mixture of different chemical molecules on the nanotube surfaces [9]. Noncovalent or covalent functionalization are the two ways to modify the surface in which molecules on the surface are deposited by means of van der Walls forces and latter method is based on direct covalent modification of the MWCNT walls with known synthetic approaches [10, 11]. The advantage of the noncovalent functionalization is that the structure of CNTs walls is not altered and thus their mechanical properties should not change. The disadvantage of the noncovalent functionalization is that the