Poly[glycidyl oligo(oxyethylene)carbamate]s (PG-EOR′ and R-PG-EOR′): controlled synthesis and effects of molecular parameters ( and ), side groups (R′), and end-groups (R) on thermoresponsive properties

The controlled syntheses of glycerol-based polymers, involving poly(glycidol) (PG)-backbones and thermoresponsive oligo(oxyethylene)-side chains, are described. The organocatalytic ring-opening polymerizations of benzyl glycidyl ether (BnGE) were performed to produce poly(benzyl glycidyl ether)s (PBnGE n s) in which the degree of polymerization ( n ) was predetermined, followed by the removal of the inherent protection groups. For these polymerization/deprotection stages, the synthesis of two major types of polymers is emphasized, in which one is "pristine" PG without any specific end-groups (PG n ) and the other is the α-end functionalized PG with hydrophobic aliphatic and aromatic groups (R-PG n ). The post-modification reactions based on the addition reactions of isocyanate derivatives to the hydroxyl side groups were adopted for PG n and R-PG n , thus producing poly[glycidyl oligo(oxyethylene)carbamate]s with diverse structures. The structures can generally be expressed as PG n -EO m R′ and R-PG n -EO m R′, where (i) the degree of polymerization ( n ), (ii) the alkyl group at the periphery of the side groups (R′), (iii) the number of oxyethylene chains ( m ), and (iv) the α-end group (R) can be independently controlled and/or selected. The effects of the parameters/structures (i)-(iv) on the thermoresponsive properties and the supporting data for the phase transitions in aqueous media are described in detail. The organocatalytic ROP and the post-modification reaction produced glycidol-based polymers with a variety of structural characteristics, which changed their shapes over a wide range of desired temperatures.