Synthesis And Solution Properties Of Fluorinated Hyperbranched Amphiphilic Polymer

In this paper, hyperbranched polyglycerol with narrow molecular weight distributions were obtained with living ionic polymerization, the atom transfer radical polymerization (ATRP) was used to prepare series of core-shell fluorined hyperbranched polymer (PG-b-PTFEMA)with hyperbranched polyether as core and trifluoroethyl methacrylate as monomer. With analyzing the dynamic surface (interface) tension at organic solvents, the adsorption parameters and adsorption kinetics of PG-b-PTFEMA on the surface of dimethyl sulfoxide and interface of chloroform/water were obtained.The first part of this paper mainly covered the synthesis and characterization of poly(glycerol)-b-poly(trifluoroethyl methacrylate) (PG-b-PTFEMA). In our previous work, we had synthesized a series of hyperbranched polymers poly(glycerol)-b-poly(hexafluorobutyl acrylate)and examined the surface behavior in ionic liquid. Due to steric hindrance, the degree of polymerization of the poly(hexafluorobutyl acry late) block is limited. In order to find the effect of fluorocarbon segments on the surface active properties of the hyperbranched polymer with more fluorinated branches, using 2,2,2,-trifluoroethyl methacrylate (TFEMA) as monomer, we synthesized PG-b-PTFEMA which having longer and denser fluorocarbon chains. With varying the monomer-to-initiator ratio and reaction temperature on ATRP, a molecular weight controlled synthesis for PG-b-PTFEMA was achieved by adjusting the reaction time. The structure of product was characterized by NMR, FT-IR and GPC, etc.The second part described the research on surface/interface active properties and adsorption kinetics of the polymer at the DMSO/air and chloroform/water interface. The influence of length of the fluorine-containing segment on surface/interface activity and thermodynamic data were discussed by analyzing surface/ interfacial tension. The results showed that: PG-b-PTFEMA can reduce surface/interfacial tension obviously. The surface/interface tension is decrease with increasing of solution concentration. The longer PTFEMA branches of PG-b-PTFEMA will lead to lower CAC value and resulting shorter time to reach equilibrium. Moreover, the kinetics of adsorption of the polymers at chloroform/water interface were analyzed with pure diffusion model (Joos equation) and diffusion-reorientation model(Ward-Tordai equation).The result showed that:at the earlier stages of adsorption, the transport of PG-b-PTFEMA from chloroform solution to chloroform-water interface is governed by pure diffusion-controlled mechanism; at the end stages of adsorption, the mixed diffusion-reorientation mechanism is more reasonable in describing the adsorption kinetics.