| This thesis mainly studies the design, synthesis and characterization of the novel carbon nanotubes based chain transfer agent, carbon nanotubes based macroinitiator and their application in the carbon nanotubes surface grafted series of polymer via living/controlled radical polymerization. The main content is described below.1. Design, synthesis and characterization the novel carbon nanotubes based chain transfer agent. MWNTs was oxidized by HNO3, inrtroducing -COOH to the surface of MWNTs. The -COOH was converted to -COCl via acylate. The high reactivity of -COCl reacted with HEBrIB, to obain bromized MWNTs. Followed by reacted with PhC(S)SMgBr, then the RAFT agent was anchored to the surface of MWNTs (MWNT-SC(S)Ph). The measurement of TGA showed that the mol content of RAFT agent vs carbon element was about 0.77 mol%.2. Using the carbon nanotubes based chain transfer agent, we grafted PS, PMMA, PMMA-b-PS from the surface of MWNTs via surface in situ RAFT polymerization method. The molecular structure and composition of the MWNTs/polymer hybrids were characterized by FTIR, NMR and XPS. The TGA measurements showed that the content of the grafted polymer can be adjusted by the ratio of the monomer and the chain transfer agent, so the polymerization process is controlled. After grafted with polymer, the MWNTs can soluble in the good solvent of the grafted polymer, and the graft level affects its solubility stability. The covalent grafted polymer can be approved by TEM and SEM images directly. This eatablishes the foundation for the process and application of the carbon nanotubes to a certainty.3. Using the carbon nanotubes based chain transfer agent, we grafted thermo-sensitive PNEPAM from the surface of MWNTs via surface in situ RAFT polymerization method. The molecular structure and composition of the MWNTs/polymer hybrids were characterized by FTIR, NMR and XPS. The TGA measurements showed that the content of the grafted polymer can adjusted by the ratio of the monomer and the chain transfer agent, so the polymerization process is controlled. The covalent grafted polymer can be approved by TEM and SEM images directly. The MWNT-PNIPAM hybrids have the temperature-responsive properties, silimar to that of the noumenal PNIPAM. In succession, we, initiated the polymerization of NIPAM from the surface of MWNTs (MWNT-PS-b-PNIPAM) by using the PS grafted MWNTs (MWNT-PS) as the chain transfer agent, and the molecular structure and composition of the hybrids were characterized by FTIR, NMR and XPS. The TGA measurements showed that the content of the grafted polymer can be adjusted by the polymerization time, so the polymerization process is controlled. The MWNT-PS-b-PNIPAM hybrids also have the temperature-responsive properties, silimar to that of the noumenal PNIPAM. This should broaden the application of carbon nanotubes in the chemical wave, adsorption and separation, sensor and drug delivery system fields.4. Using the carbon nanotubes based macroinitiator, we grafted thermo-sensitive PNIPAM from the surface of MWNTs via surface in situ ATRP polymerization method. The molecular structure and composition of the MWNTs/polymer hybrids were characterized by FTIR, NMR and XPS. The TGA measurements showed that the content of the grafted polymer can be adjusted by the polymerization time, so the polymerization process is controlled. The covalent grafted polymer can be approved by TEM and SEM images directly. US-DSC measurements showed the MWNT-PNIPAM hybrids have the temperature-responsive properties, silimar to that of the noumenal PNIPAM. The phase transition temperature of the hybrid is about 33℃in the heating process, and about 31℃in the cooling process, respectively (where both the heating and cooling rates were 1.00℃/min). |
