Synthesis And Thermoresponsive Properties Of Polyglycidol Derivatives

Thermoresponsive polymer material is a type of intelligent polymer material that has attracted much attention in recent years,due to this material can be widely used in biomedical,chemical and textile and other fields.Modern social science and technology are developing rapidly,people have higher requirements for new intelligent materials,therefore,there is great significance to explore the new thermoresponsive polymer materials for the development of intelligent polymer materials is of great significance.We have studied the thermoresponsive property of polyglycidyl oligo?oxyethyl?carbamates?PG-OE?prepared by the synthesis and post-modification of polyglycidol?PG?.The ring opening polymerization?ROP?of benzyl glycidyl ether?BnGE?using3-phenylpropanol?PPA?as the initiator and phosphazene base of t-Bu-P₄ as the catalyst in toluene was carried out using different[BnGE]0/[t-Bu-P4]0/[PPA]0 ratios to afford well-defined poly?benzyl glycidyl ether?s?PBnGEs?with DPs of 48,73,97,123,and 144.Polyglycidol?PG?was prepared by the deprotect of benzyl groups in PBnGE using H₂/Pd and then was reacted with oligo?oxyethyl?isocyanates?OE-IC?to afford PG carbamates with one,two,and three oxyethyl units?OE??PG-OE₁,PG-OE₂ and PG-OE₃,respectively?.The structure and molecular weight(M_n.NMR)of PG-OE₁,PG-OE₂,and PG-OE₃ were confirmed using the ¹H and ¹³C NMR measurements.Lower critical solution temperature?LCST?,which was determined by the cloud point of the transmittance in UV-Vis.These results indicated that 40 g/L is the optimum concentration of polymer aqueous solution for phase change experimental.The T_cpp increased in the order of PG₁₄₄-OE₁<PG₁₄₄-OE₂<PG144-OE3 and slightly decreased with the increasing polymerization degree of PG,such as from 78.5°C to 74.5°C for PG₄₈-OE₁ to PG₁₄₄-OE₁ from 85°C to 81°C for PG₄₈-OE₂ to PG₁₄₄-OE₂ and from 93°C to 89°C for PG₄₈-OE₃ to PG₁₄₄-OE₃.The liquid-solid transition was observed using the ¹H NMR and dynamic light scattering measurements.These results show that the phase transition behavior of PG-OE caused by the dehydration from the OE side chain above the T_cp.