Block Polymer Synthesis And Its Composites With Cnts

In this thesis, the copolymers were successfully synthesized by cerium(IV) ammonium nitrate (CAN)/HC1 and ATRP. The copolymers were used to improve the dispersion of CNTs by nonconvalent modification. Composite materials of copolymer/CNTs were made and characterized by a series of means. The main contributions are as follows:(1)A amphiphilic triblock copolymer (polyacrylonitrile-poly(ethylene oxide)-polyacrylonitrile)(PAN-PEG-PAN) was successfully prepared by free radical polymerization through OH/Ce4+ redox system. The rheological properties was investigated for the blend solution of PAN-PEG-PAN and MWNTs. The results showed that the viscosity and modulus of the solution increased with increasing MWNTs content. The PAN-PEG-PAN/MWNTs composite fibres were processed using electrostatic spinning. Scanning electron microscopy were employed to observe the distribution of the MWNTs in the composite in a microscopic scale, indicating MWNTs dispersed well in the composite. The mechanical properties of composite membranes was investigated. The results showed that as MWNTs loading increased from 10% to 20%, the tensile strength increase to the double, but the elongation at break reduced by 40%.(2)The copolymer PEG-PDMAEMA were successful synthesized by ATRP. Stimuli-responsive properties of PEG-PDMAEMA/SWNTs aqueous solution were investigated and the results showed that SWNTs dispersions that respond to temperature and pH changes.The fluorescence measurement was used to study the kinetic of the formation of the inclusion compound, results shown that the increase of concentration of MWNTs can promoted this process. The TG and SEM results showed that the thermal stability and morphology of inclusion compound had little changed. The temperature-responsive properties of hybrid hydrogel were investigated by rheology, MWNTs improved the mechanical properties of hybrid hydrogel.(3)The Poly(EO-co-EPEE) was successfully prepared by anionic polymerization and then hydrolyzed in acidic condition to get linear poly(EO-co-Gly). The brush copolymer of poly(EO-co-Gly)-g-PDMAEMA was synthesized by ATRP and 1H-NMR and GPC results indicated that it was successfully prepared. The rheological properties was investigated for the 40% aqueous solution of poly(EO-co-Gly)-g-PDMAEMA and the results showed that the viscosity and modulus of solutions were sensitive to pH and temperature. The LCST of copolymer decreased with increasing pH and the hysteresis and the shear thickening were discovered.