Dendritic Polymer-functionalized CNTs

In addition to linear polymers, HPs can also be grafted on CNTs by the grafting from approach. HPs are globular, highly branched macromolecules 

MWCNTs by self-condensing vinyl polymerization RQpi62-i64 

1 Self-condensing Vinyl (Co)Polymerization (SCVP/SCVCP) 

The SCVP approach to HPs was first reported by Frechet and co-workers through polymerization of an AB -type monomer. Normally, the AB contains a vinyl group and a functional group that can initiate the polymerization of the vinyl moiety. Hence, the AB is also named as an inimer (inimer = initiator + monomer).Up to date, SCVP has been extended to cationic, anionic and radical polymerization systems, preparing various libraries of HPs and HP-modified solid surfaces. If the AB  

Hong et grafted HPs from the MWCNT surfaces by SCVP of another AB inimer, 2-[(bromobutyryl)oxy]ethyl acrylate (BBEA), in toluene at 100 °C for 24 h via the ATRP process using CNT-Br-4 as the macroinitiator and CuBr/PMDETA as the catalyst.The grafted HP content increased with increasing the reaction time, and approached 80 wt% at 24 h. They also carried out successfully SCVCP of BBEA and rBA via the ATRP process. 

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The grafting to method was used for the preparation of composites with the polymers containing reactive functional groups. One of the first examples of the grafting to approach was published by Fu et al in 2001. In this work, carboxylic acid groups on the nanotube surface were converted into acyl chlorides by refluxing the samples in thionyl chloride. Then the acyl chloride functionalised CNTs have been reacted with hydroxyl groups of dendritic PEG polymers via esterification reactions. 

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