Study Of Synthesis And Application Of Branched Poly(Styrene-co-maleic Anhydride) And Its Derivative

Since its concept introduced, because of their attractive features such as multiple endgroups, three-dimensional globular structure, lower solution viscosity and improved solubility,branched polymers have received much attention. Many synthetic approaches have been usedto prepare branched polymers such as atom transfer radical polymerization (ATRP), reversibleaddition-fragmentation chain transfer polymerization (RAFT) and self-condensing vinylpolymerization (SCVP). However, many methods for synthesis of branched polymers alsohave inevitable imperfections, including products’ structure is uncontrollable, the need forcomplex monomers, harsh reaction conditions and operation process is complicated. Thistopic is mainly divided into three parts. The first part is mainly on the synthesis of branchedpoly(styrene-co-maleic anhydride)(BPSMA) through the method of mercapto chain-transferpolymerization (MCTBP). Then the self-assembly of BPSMA was studied and the applicationof composite materials of BPSMA/Multi-walled carbon nanotube (MWCNT) was researched.The last part is about the synthesis of photoresponsive poly(styrene-co-maleic anhydride)derivative. The application of dispersing auxiliary for MWCNT was explored. Moreover, gasresponse of composite material was studied.1) BPSMA was synthesized through the method of MCTBP with maleic anhydride (MA),styrene (St),4-vinyl benzyl thiol (VBT) as branched monomer and AIBN as the initiator. Theinfluence of mole inventory and polymerization time on structure and properties of BPSMAwas examined. Compared with line poly(styrene-co-maleic anhydride)(LPSMA) onmolecular weight (Mn/Mw/PDI), viscosity (η), glass transition temperature (Tg) andconversion rate, branched structure of BPSMA was certified.2) On the basis of chapter two, we studied the influence of mole inventory andpolymerization time on the self-assembly of BPSMA. Particle size and morphology ofmicelles were charactered by dynamic light scattering (DLS) and transmission electronmicroscope (TEM). By the function of micelle cladding, branched polymer can enhancegreatly disperse stability of MWCNT in aqueous solvent. The morphology ofBPSMA/MWCNT composites was charactered by scanning electron microscope (SEM) andTEM. BPSMA/MWCNT composites can be used as gas sensitive material. With theresistance variation interdigital electrode with composites, it can be found that the gassensitive material has high selectivity and responsibility to common organic solvents such asmethanol, isopropanol and ammonia.3) On the basis of BPSMA, photosensitivity poly(styrene-co-maleic anhydride)derivative (BP(St-co-MA-AMC)) was prepared by ring-opening reaction. By introducing thecombination technique with self-assembly and UV curing, MWCNT can be dispersed inaqueous solvent steady. According to the result of DLS and TEM, it found that beforeMWCNT adding, BP(St-co-MA-AMC) can be gathered into micelles. However, aftercompositing with MWCNT, polymer was cladding on the surface of MWCNT. The structureand properties of BP(St-co-MA-AMC) were examined by fourier transform infraredspectroscopy (FT IR), thermogravimetric analysis (TGA), reman spectroscopy, TEM andSEM. Moreover, the influence of the concentration ratio of BP(St-co-MA-AMC) and MWCNT, the time of UV irradiation and the time of supersonic on dispersion stability ofMWCNT in solvent. The composite can film-forming on interdigital electrode. The resultshowed that the composite has high selectivity and responsibility to common organic solventssuch as methanol, isopropanol and ammonia.