树状化-线形两亲嵌段聚合物的合成及自组装研究  

SYNTHESIS AND SELF-ASSEMBLY OF DENDRONIZED-LINEAR AMPHIPHILIC BLOCK COPOLYMER

作　　者：伊卓[1,2] 习复[1] 陈永明[1] 

机构地区：[1]中国科学院化学研究所高分子物理与化学国家重点实验室,北京100190 [2]中国石油化工集团公司北京化工研究院,北京100013

出　　处：《高分子学报》2011年第5期494-501,共8页Acta Polymerica Sinica

摘　　要：合成了缩酮保护的一代甲基丙烯酸羟乙酯单体DHEMA(G1),通过顺序ATRP聚合方法,制备得到大分子引发剂PDHEMA(G1)-Br,再引发苯乙烯单体得到一代嵌段聚合物PDHEMA(G1)-b-PS.以PDHEMA(G1)-b-PS为反应前体,通过重复的缩酮保护和脱保护反应,进一步得到了二代和三代的树状化-线形两亲嵌段聚合物PDHEMA(Gn-OH)-b-PS(n=2～3).IR和1H-NMR表征结果证实了两亲嵌段聚合物的生成.在DMF/CH3 OH溶液组装体系中,当CH3 OH含量为50 wt%时,PDHEMA(G1-OH)-b-PS、PDHEMA(G2-OH)-b-PS和PDHEMA(G3-OH)-b-PS均形成核壳结构的球形胶束,且随树状化嵌段代数的增加,球形胶束尺寸也相应增大.对于PDHEMA(G3-OH)-b-PS,当CH3OH含量增加到66 wt%时,出现支化结构和环形结构的棒状胶束复合体与少量球形胶束共存,继续增加CH3OH含量到75 wt%,只能观察到支化和环形结构的棒状胶束复合体.研究认为,在棒状胶束生长过程中同时存在支化作用和成环作用是棒状胶束复合体中多环结构形成的主要原因.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.

关 键 词：树状化聚合物 两亲嵌段聚合物 ATRP 自组装 

分 类 号：O631.3[理学—高分子化学]