The monomer (DHEMA(G1)) was synthesized by esterification of the 2-hydroxyethyl methacrylate with acetonide protected 2

2-bis(methylol)propionic acid

and then undergone the ATRP to give the macroinitiator PDHEMA(G1)-Br.By using PDHEMA(G1)-Br to initiate styrene

PDHEMA(G1)-b-PS block copolymer was prepared.Based on the PDHEMA(G1)-b-PS as reactive precursor

through iterative process of the deprotection of acetonide and dendronization by esterification with bis-MPA anhydride

the dendronized-linear amphiphilic block copolymers PDHEMA(Gn-OH)-b-PS(n=2~3) were prepared

and the asymmetrical structure of designed copolymers was a combination of a hydrophilic multihydroxyl dendronized PDHEMA(Gn-OH) block and a hydrophobic linear PS block.The resultant copolymers were characterized by IR and 1H-NMR.The self-assembly morphology of PDHEMA(Gn-OH)-b-PS(n=1~3) in the binary solvent mixture (DMF/CH3OH) was investigated with the copolymer concentration at 2 mg/mL.When the CH3OH content was at 50 wt%

PDHEMA(G1-OH)-b-PS

PDHEMA(G2-OH)-b-PS and PDHEMA(G3-OH)-b-PS self-assembled into spherical micelles with core-fringe structure.The diameter of micelles increased with increasing generation of dendronized blocks.For the copolymer PDHEMA(G3-OH)-b-PS

when the CH3OH content was at 66 wt%

the compound rodlike micelles containing branch and ring structure were formed and spherical micelles were also encountered occasionally.When the CH3OH content reached 75 wt%

only the compound rodlike micelles contaning branch and ring structure were observed.The unique morphological variety of muti-rings could be attributed to the coexistent effect of branch and ring during the development of rodlike micelles.