Ring-opening Polymerization ROP Approach to Polymer-grafted CNTs

4 Ring-opening Polymerization (ROP) Approach to Polymer-grafted CNTs 

Choi and co-workers synthesized 6-amino-1-hexanol-immobilized SWCNTs by immersing the acyl chloride-functionalized SWCNTs into a DMF solution of 6-amino-1-hexanol for 12 h, and grafted poly(p-dioxanone) (PDX) from the SWCNT surfaces by in situ ROP in toluene at 100 °C for 3 days with tin(II) 2-ethylhexanoate [Sn(Oct)2] as the catalyst. The 10% weight-loss temperature of grafted polymer is higher than that of free polymer by approximately 20 °C. 

Yang et al. developed a green chemical functionalization method using water and room temperature ionic liquids as the reaction media. By in situ ROP of E-caprolactone from hydroxyl-modified MWCNTs in ionic liquids of l-butyl-3-methylimidazolium tetrafluoroborate, MWCNT-g-PCL was obtained. When the reaction time was increased from 2 to 8 h, the PCL fraction improved from 30.6 to 62.7 wt%.  

Another biodegradable polymer, poly(L-lactide) (PLLA), was also grafted from MWCNT surfaces successfully using Sn(Oct)2 as the catalyst. Upon 

Yao et al prepared polypeptide-grafted MWCNTs by ROP of benzyl-L-glutamate AT-carboxyanhydride (BLG-NCA) initiated with amino-funetiona-lized MWCNTs. TEM measurements showed that the thickness of the polypeptide shell was about 4.5 22 nm, depending on the grafted polypeptide amount. 

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