Synthesis Of Amphiphilic Graft Copolymer From Grafting Through And Its Micellar Behavior In Aqueous Solution

Amphiphilic copolymer is a polymer that has affinity both with water and oil. In selective solvents, the amphiphilic copolymer is energetically favorable to form micelles with its insoluble groups forming the core and the soluble groups forming the outer shell through the self-assembly. Due to their unique chemical and physical properties, intensive interests on the self-assembly of amphiphilic copolymers in solution have been risen. It has potential applications in nano-materials, polymeric surfactants, biomedical substances and petrochemical technology. These copolymers have a larger molecular weight and high surface activity and could form different types of stable spherical micelles. People expect to get the well-defined and controlled copolymer which is the main developing direction of modern synthetic polymer Chemist.In this study, a graft copolymer with a P(AM-MA) backbone and n-octylphenyl polyoxyethylene (C₈PhO₁₀) side was designed and synthesised chains by means of"grafting through"technique. The micellar behavior of the amphiphilic graft copolymer was examined by surface tension measurements in water and the shape was studied by TEM and AFM. The preliminary findings were presented.This thesis consists of three parts:1. Chapter 1 reviews the concept of amphiphilic graft copolymer, structural properties, applications and their progress in synthesis.2. In Chapter 2, a surface-active macromonomer of C₈PhEO₁₀Aac was prepared with C₈PhEO₁₀H and methacryloyl chloride using toluene as solution in the presence of copper(I) chloride and triethylamine. The effects of the percentage of C₈PhEO₁₀H conversion have been discussed. The macromonomer exhibited the expected structure as indicated by the characterization with FT-IR and ¹H-NMR.3. In Chapter 3, water-soluble P(AM-MA)-g-C₈PhO₁₀ of PAM as main chain and C8PhEO10Mac as graft chains were synthesized by free radical copolymerization using K₂S₂O₈ as initiator in water. The copolymers obtained were characterized by FT-IR, ¹H-NMR, TG, DTA. The synthesis of graft copolymer of PAM as main chain was feasible and successful. 4. In Chapter 4, The CMC and correspondingγCMC values of the graft copolymer were obtained by surface tension measurements in aqueous solution. The shapes and sizes of P(AM-MA)-g-C₈PhO₁₀ micelles in water have been discussed using TEM and AFM. The results showed that the micellar shapes and the sizes were dependent on copolymer concentration, as the copolymer concentration increases. The micellar sizes became larger.