具有光学活性的两亲性聚炔-聚乙二醇单甲醚接枝共聚物的合成与表征  

SYNTHESIS AND CHARACTERIZATION OF OPTICAL-ACTIVE AND AMPHIPHILIC GRAFT COPOLYMERS OF POLYACETYLENE-MPEG

作　　者：余婷[1] 赵东[1] 张立群[1] 岳冬梅[1] 

机构地区：[1]北京化工大学碳纤维及功能高分子教育部重点实验室北京市新型高分子材料制备与成型加工重点实验室北京化工大学材料与科学工程学院,北京100029

出　　处：《高分子学报》2011年第3期281-286,共6页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号20774009);教育部留学回国人员科研启动基金(基金号LX2008-04)资助项目

摘　　要：设计并合成了含手性侧基和含亲水性大分子侧基的接枝聚炔共聚物[聚(丙炔酸薄荷醇酯-co-丙炔酸聚乙二醇单甲醚酯)(poly(a-co-b),(a:propiolic acid L-menthol ester;b:propiolic acid polyethylene glycolmonomethyl ether ester)).通过比旋光度([α]D),圆二色光谱(CD)表征手段发现共聚物poly(a-co-b)具有很强的光学活性且能形成单一方向的螺旋构象.另外还考察了共聚物中聚乙二醇单甲醚(MPEG)含量、溶剂极性及时间对共聚物的光学活性和二级结构的影响,结果表明,随着MPEG含量的增加,共聚物的光学活性会降低.在所选的4种溶剂中(三氯甲烷,四氢呋喃,二氯甲烷,苯),共聚物的螺旋构象在三氯甲烷溶剂中最能稳定存在.然而此类共聚物的二级结构在溶剂中是不稳定的,其光学活性会随着时间的延长而逐渐减弱.The novel graft copolymers of （poly（ a-co-b）, （a：propiolic acid L-menthol ester; b：propiolic acidpolyethylene glycol monomethyl ether ester）） having C-chirality and hydrophilic macromolecules as pendant groups were synthesized via copolymerization of monomer a and monomer b by using （nbd）Rh^＋ [ η^C6H5B^-（C6H5）3] as catalyst. The structure of copolymers was characterized by FTIR. Moderate molecular weights （Mn） （13000 ～ 15000） and Mw/Mn（2.4 ～ 2.2） of copolymers were measured by GPC. The maximum amount of MPEG for successful copolymerization of copolymers was 20 mol%. The optical activity and secondary structure of the copolymers were characterized by specific rotations （ [ α ] D） and circular dichroism （CD） spectra. The copolymers with relatively low yields （32.3% ～46.6% ） exhibited high optical activity in contrast to chiral monomer,which accorded with the “Chiral Amplification” effect. All the copolymers formed single helical conformation in despite of adding the long chain of MPEG. Certainly, the optical activity of copolymers decreased with the increase of MPEG content. The helical conformation of the copolymers kept the better stability in CHCl3 comparing to other three selective solvents. As the time delay, the optical activity of the copolymers decreased due to their instability. By adding the hydrophilic chain of MPEG,rigid and flexible chain were linked finely and formed the hydrophilic/hydrophobic interaction, which provided the best driving force for self-assembly behavior.

关 键 词：聚炔 光学活性 螺旋结构 两亲共聚物 

分 类 号：O631.3[理学—高分子化学]