Amphiphilic Random Copolymer Synthesis And Performance Studies

In this paper, an alternating copolymer, poly(styrene-alt-maleic anhydride)(PSMA), was synthesized by free radical polymerization. An amphiphilic alternating copolymer poly(styrene-alt-maleic acid-octylamine) (PSMAO) was prepared by the ammonolysis of PSMA with octylamine. Fourier IR spectra, Differential scanning calorimetry and Thermal gravimetric analyzer were used to characterize the structure and performance of the polymer. The micelles of PSMAO were prepared by the self-assembly of the compolymer in DMF/H2O solution. UV spectrophotometer, Zetasizer and Transmission electron microscopy were used to study self-assembly process and the morphology of the micelles. Factors such as the degree of ammonolysis, the initial polymer solution concentration, pH, Ca2+ and so on had direct impacts on the micelle formation, the critical water content(CWC) and particle size distribution. The study showed that the oil phase, micelle concentration, micelle hydrophilicity affected the type and stability of emulsion.With the degree of ammonolysis increasing, the hydrophilicity of PSMAO increased, the CWC of PSMAO increased from 10.5% to 22.3% and the particle size(Rh) from 33.8nm to 72.5nm. When the pH of the solution decreased, the ionization of carboxylic acid became harder, the increased electrostatic repulsion made the copolymer's structure closed. When Ca2+ content in the solution was less than 0.03mg/mL, two carboxylate ions connected by Ca2+ were within the same micelle, micellar particle size decreased; When Ca2+ content was greater than 0.03mg/mL, two carboxylate ions connected by Ca2+ were in different micelles, micellar particle size increased.A series of sulfonated polystyrene(PSS) with different sulfonation level were prepared by Makowski's method. Fourier IR spectra was used to characterize the molecular structure of polymer. Their sulfonation level had the effect on the solubility in several solvents. The water absorption and the contact angle of PSS with water were studied by means of their films. UV spectrophotometer and Zetasizer were used to study the self-assembly process and the micells particle size distribution of PSS in DMF/H2O solution. The emulsion polymerization of styrene stabilized by NaPSS60 was investigated. The size distribution of Polystyrene latex particles was studied by Zetasizer. When the NaPSS60 content in the solution was greater than Critical micelle concentration(CMC), polystyrene latex particle size was less than 100nm.