Synthesis, Characterization And Pervaporation Performance Of PE-b-PEO Blcok Copolymers

High quality polymer materials is important in pervaporation (PV) separation of Aromatics/Aliphatics. Poly(butadiene-b-ethylene oxide) block co-polymers(PB-b-PEO block co-polymer) were synthesized using the anionic polymerization method. Then they were hydrogenated to be Poly(ethylene-b-ethylene oxide) block co-polymers (PE-b-PEO block co-polymer). These PE-b-PEO homogeneous membranes were used in pervaporation for Aromatics/Aliphatics separation.PB-OH was synthesised by using cyclohexane(solvent)\ n-butyllithium(initiator)\butadiene(monomer) and thylene oxide(monomer). The PB-OH capping efficiency was characterized by GPC and 1H NMR. The results indicated that the capping efficiency was 99.9% when ethylene oxide was directly added into polybutadiene system.Poly(butadiene-b-ethylene oxide) block co-polymer was synthsised using PB-OH as initiator\thtrahydrofuran as solvent\potassium naphthalenide as initiator. The structures of the polymers were characterized by GPC\FT-IR\H NMR\DSC. The results show that well-defined target products with controlled molecular weight and low dispersities were obtained.PE-b-PEO block co-polymers were analyzed by PV separation of toluene/heptane. With increasing of the PEO blocks, the separation factor increased, and permeation flux decreased at 60℃. With increasing of the PE blocks, the separation factor increased, and permeation flux decreased at 60℃. The pervaporation performance is opposite at 80℃.