Synthesis and Solution Properties of Poly(vinyl Ether) with Long Alkyl Chain Pendants
|School||Sun Yat-sen University|
|Course||Polymer Chemistry and Physics|
|Keywords||Cationic Polymerization Polyethylene ether Thermal response Phase separation Resonance Light Scattering Technique|
The polyvinyl ether-based material in an organic solvent in the UCST-type phase separation is interesting. The vinyl ether is a typical class of monomers suitable for the living cationic polymerization. Select a special terminating agent, fluorescently labeled polyvinyl ether can be obtained by living cationic polymerization. Established based on the the ordinary fluorescence spectrophotometer synchronization scanning technology resonance light scattering (RLS) is a high sensitivity and convenient study polymer solution phase separation method. Based on this, uses a living cationic polymerization method synthesized narrow molecular weight distribution containing a long alkyl side chain, poly octadecyl vinyl ether (PODVE), the use of RLS technique UCST-type in its methylene chloride solution phase separation was studied. Specifically, the paper work can be divided into two parts: The first part is the synthesis and characterization of polymer parts. ODVE the active cationic polymerization is IBEA (1 - (isobutoxy) ethyl acetate) / EtAlCl2 plus as an initiator system of ethyl acetate at 30 ° C in n-hexane solvent. By 2 - naphthyl mercaptan and ammonia-containing methanol as a terminating agent were obtained the naphthyl the tag PODVE and ordinary PODVE. The change IBEA concentration and the polymerization time to achieve a molecular weight the regulation of the PODVE. By 1H NMR, FT-IR, GPC and UV-vis the technical structure of each polymer characterization. The second part of the solution properties. Comparison the different end group PODVE of solution to the absorption spectra of different measured naphthyl labeled PODVE room temperature under fluorescence spectroscopy, and further illustrate the success of the fluorescence-labeled. RLS the PODVE / methylene chloride solution of the heat-induced phase separation process. Maximum scattering wavelength at RLS intensity variation with temperature show that the changes in the morphology and aggregation of the phase separation process induced by crystallization in the cooling process PODVE chain. Warming leads to aggregates swell PODVE chain dissociation, the final PODVE Chain recover at a higher temperature to cool down before the state. Were investigated the dependence of the phase separation of the concentration and molecular weight of the starting temperature (Onset temperatures of phase separation, Tp). The PODVE / methylene chloride solution at different temperatures, phase separation of time-dependent, and further quantitative kinetic processes described using the Avrami equation and the Arrhenius equation the apparent activation energy of the phase separation process calculations.