Poly /MWCNT nanocomposites

Baek and co-workers grafted hyperbranched poly(ether ketone)s (HPEKs) on to MWCNTs through an in situ polycondensation of A3 (trimesic acid) and B2 (phenyl ether) monomers in the presence of poly(phosphoric acid) and P2O5. Due to the globular molecular architecture of HPs, the morphology of the nanocomposites resembled mushroom-like clusters on MWCNT stalks . The HPEK-g-MWCNT nanocomposites were soluble in polar aprotic... 

Where, h=initial thickness, ( =angular velocity, p=density, r =viscosity, and t=time. As for example, 60 nm thin film can be obtained by spin coating of a stock solution of poly(2,5-dimethylaniline) (PDMA)-MWCNTs nanocomposite in chloroform with a concentration of 0.25 mg/ml at a speed of 250 rpm for 5 s and then at 1000 rpm for 10 s (for drying) [39]. 

Information about surface morphology is also obtained from SEM studies. In general, the intercalated clay layers show an intense peak in the range of 1.5° ° (29 value), whereas exfoliated systems have no distinct peak in that range for their loss of structural integrity shown in the XRD pattern of the nanocomposites. XRD studies indicate that there is no infiu-ence of nanomaterial on poly(e-caprolactone)diol PCL crystallinity in sunflower oil-based hyperbranched polyurethane/silver nanocomposite, but that crystallinity is enhanced in castor oil or Mesua ferrea oil-based hyperbranched polyurethane/MWCNT nanocomposites. ... 

Conductive polymer nanocomposites may also be used in different electrical applications such as the electrodes of batteries or display devices. Linseed oil-based poly(urethane amide)/nanostuctured poly(l-naphthylamine) nanocomposites can be used as antistatic and anticorrosive protective coating materials. Castor oil modified polyurethane/ nanohydroxyapatite nanocomposites have the potential for use in biomedical implants and tissue engineering. Mesua ferrea and sunflower seed oil-based HBPU/silver nanocomposites have been found suitable for use as antibacterial catheters, although more thorough work remains to be done in this field. ° Sunflower oil modified HBPU/silver nanocomposites also have considerable potential as heterogeneous catalysts for the reduction of nitro-compounds to amino compounds. Castor oil-based polyurethane/ epoxy/clay nanocomposites can be used as lubricants to reduce friction and wear. HBPU of castor oil and MWCNT nanocomposites possesses good shape memory properties and therefore could be used in smart materials. ... 

Wang et al. [196] reported synthesis of Mn02/CNT nanocomposites. The Mn02 nanoparticles were coated on the CNTs by a facile direct redox reactirm between KMNO4 and CNT without any other oxidant or reductant addition. Xia and coworkers [197] synthesized poly( -caprolactone) (PCL)/functionalized MWCNT nanocomposites and their electroactive shape memory properties were demonstrated. The crosslinking reaction of the pristine PCL was realized by using benzoyl peroxide as an initiator. The raw MWCNTS were prefunctionalized by acid-oxidation processes and covalent grafting with PEG. 

Among the PHAs, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, was mostly used to produce nanocomposites with carbon nanotubes. Lai et al. (2004) produced nanocomposites of PHBV (4.5 mol% of HV) and MWCNT. PHBV/ MWCNT nanocomposites with 2 wt% of MWCNT were prepared using trichlo-romethane as solvent. The mixture was sonicated, then the solvent was allowed to... 

Fig. 3 (A) SEM images of poly(styrene-b-ethylene-co-butylene-b-styrene)/MWCNT nanocomposites with nanotube loading of 2.5 wt% [85]. (B) Polarizing optical micrographs of (a) neat TPU and, (b) its nanocomposite of 4 wt% CNF [83]...

Figure 12.20 TEM images of (a) LiFeP04/ poly(3,4-ethylenedioxythiophene) (PEDOT) and (b) LiFeP04/MWCNT nanocomposites.

Alternatively, hydrophilic multi-hydroxyl poly(GMA-OH)-grafted MWCNTs could be converted into multicarboxyl polymer-functionalized CNTs by reaction with succinic anhydride and then used as templates to efficiently sequestrate metal ions such as Ag", Co ", Ni , Au , La and (Scheme 5.3), generating MWCNT-polymer/metal hybrid nanocomposites, nanowires or necklace-like nanostructures, depending on the grafted polymer content and the nature of the captured metals. The combination of SEM, TEM and energy dispersive spectroscopy (EDS) characterizations demonstrated the structure and elements of the hybrid nano-objects. 

PPy has also been used in combination with CNTs to obtain an anticorrosion coating. Hermas [69] studied PPy-CNTs coating applied on stainless steel by in situ EP of PPy-oxidised multi-walled carbon nanotubes (MWCNTs) and PPy-oxidised SWCNTs composites from 0.1 M oxalic acid by using cyclic voltammetry. The results show that the addition of the oxidised carbon nanotubes greatly enhances the EP process, especially in the case of oxidised SWCNTs. Similar results are reported in Ref. [70], referring to electrodeposition of a nanocomposite coating made of oxidised CNTs and poly(o-phenylenediamine) (PoPD) on a stainless steel. Also in this case the presence of the CNTs enhances the deposition of the PoPD and this enhancement is more evident with SWCNT than with MWCNTs. The nanocomposite coating keeps the stainless steel in a passive state in an acidic solution. 

Sanchez studied the functionalization of oxidized SWCNTs and MWCNTs dispersed in thermoplastic elastomers based on poly(butylene terephthalate) (PBT)/ poly(tetramethylene oxide) (PTMO). These nanocomposites showed good dispersion and enhancement in thermo-oxidative stability [27]. 1 % of pristine multi-walled carbon nanotube (MWCNTs) were dispersed in silicon rubber. The SR nanocomposites showed 28 % better thermal stability and 100 % improvement in the ultimate tensile strength is achieved as compared with the pristine polymer matrix counterpart [28]. Also ionic liquids have been tested to improve the dispersion and thermal stability of MWCNTs in polychloroprene rubber (CR) showing improvement in these properties [29]. On the other hand the effect of carbon nanofiber on nitrile rubber was studied. It has been found that the nanofiber increase the thermal stability and decrease the flammability [4]. 

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