Win Min Polymer Synthesis And Performance Research

In this paper, a block copolymer, poly(styerene-alt-maleicanhydride)-b-poly(N-isopropylacrylamide), was synthesized by the method of reversible addition-fragmentation chain transfer polymerization(RAFT). Fourier IR spectra, Thermal gravimetric analyzer and Differential scanning calorimetry were used to characterize the structure and properties of the polymer. The micelles of P(St-alt-Man)-b-PNIPAAm were prepared by the self-assembly of the copolymer in DMF/H2O solution. UV spectrophotometer, nano-particle size analyzer and Transmission electron microscopy were used to research the formation and the morphology of the micelles. The initial polymer solution concentration, pH, temperature and so on infected the self-assembly process of the polymer. As the content of PNIPAAm increased, the critical water content (CWC) increased from16.1%to18.5%and the particle size of the micelles increased from101nm to238nm. When the initial polymer solution concentration increased from0.005g/mL to0.02g/mL, CWC increased decreased from28.5%to18.5%.As the pH of the solution decreased from7to3, the particle size decreased from249nm to58nm, when the pH was2, two scopes of particle size appeared. The CWC and the particle size of the micelles decreased as temperature increased.Polymer film was formed on the surface of Polystyrene plates, polymer fibers were prepared by electrostatic spinning. The film and the fibers were cross-linked by ethylenediamine. Fourier IR spectra and Contact angle meter were used to characterize the structure and properties of the polymer. The polymer film and fibers were hydrophilic at room temperature. The contact angle increased above LCST of the polymer, the hydrophilic nature decreased after cross-linking.