Thermoset/carbon nanotubes

Battisti, A., Skordos, A.A., and Partridge, I.K. 2009a. Monitoring dispersion of carbon nanotubes in a thermosetting polyester resin. Compos. Sci. Technol. 69 1516-1520. 

The same thermosetting polystyrene SMP was used in this study. In addition to the 40% by volume of glass microbaUoons, 0.15% by volume of multiwalled carbon nanotubes was also added, which was the same as in Reference [38]. The multiwaUed carbon nanotubes (Cheap Tubes Inc.) have a density of 2.1 g/cm, diameter of 20-30 nm, and length of 20-30 pm. Similar to Reference [38], a two-step procedure was used to prepare the syntactic foam. First, the carbon nanotubes were added to Part A of the polymer. The mixture was mixed with the assistance of an ultrasound mixer for 30 minutes at a frequency of 20 kHz (Sonics Vibracell VC 750W) and a three-roll mill for one pass (NETZSCH type 50) (see Rgure 3.26). Second, microballoons and hardener (Part B of the polymer) were added to the carbon nanotube/Part A mixture and mixed with a spatula for 15 minutes. It was then poured into an aluminum mold of... 

In the last decade, considerable progress was observed in the field of PO/compatibil-izer (predominantly on the base of PO-g-MA)/organo-surface-modified clay nanocomposites. Polyethylene (PE), polypropylene (PP), and ethylene-propylene (EP) rubber are one of the most widely used POs as matrix polymers in the preparation of nanocomposites [3,4,6,30-52]. The PO silicate/silica (other clay minerals, metal oxides, carbon nanotubes, or other nanoparticles) nanocomposite and nanohybrid materials, prepared using intercalation/exfoliation of functionalized polymers in situ processing and reactive extrusion systems, have attracted the interest of many academic and industrial researchers because they frequently exhibit unexpected hybrid properties synergisti-cally derived from the two components [9,12,38-43]. One of most promising composite systems are nanocomposites based on organic polymers (thermoplastics and thermosets). 

Carbon nanotubes (CNTs) can be used as nano-modifiers in the thermosetting matrices due to their attractive mechanical, thermal and electrical properties. Nevertheless, the incorporation of CNTs into these matrices has not had remarkable effect on the polymers thermal properties, with some exceptions [86]. The effect of CNTs over the thermal stability of thermosetting polymers depends on some factors such as CNTs type and content, aspect ratio and dispersion, the interactions... 

Surfactants are added to a thermoset resin system to promote the dispersion of fillers in the resin matrix. Recently, surfactants have been used to disperse carbon nanotubes in polymer matrices [48-50]. Surfactants are of two types neutral and ionic. Surfactants have many applications in coating industries for the development of a water-based resin system [51]. Surfactants are added to phenolic or polyurethane foam formulation in which they facilitate formation of small bubbles. The size and uniformity of bubble formation results in a fine cell structure. A surfactant reduces the surface tension of resin formulations and provides an interface between the highly polar resin and the non-polar blowing agent. The surfactant for a particular resin system must be selected carefully so that it is compatible with the resin and resistant... 

The polymer matrix should be properly chosen before processing of carbon nanotube/polymer composites. Both thermosetting and thermoplastic... 

Mathur et al. (2010) used multi-walled carbon nanotubes (MWCNTs) to reinforce phenolic resins using both the wet and dry dispersion techniques before molding. The phenolic composites reinforced with 5% MWCNTs exhibited a flexural strength 158% higher than those of neat phenolic thermosets. 

---