【作者】 余婷；

【导师】 岳冬梅；

【作者基本信息】 北京化工大学 ， 材料科学与工程， 2010， 硕士

【摘要】 自然界中普遍存在的螺旋结构引起了人们对螺旋聚合物的广泛兴趣,而螺旋聚合物只有进一步自组装成各种生命组织才能真正在生命活动中发挥作用,因此螺旋聚合物自组装行为的研究显得尤为重要。本文合成了一系列新的聚炔类螺旋共聚物,并研究了其自组装行为。主要工作如下：1、设计并合成了一系列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)(polyacetylene—MPEG)],通过红外光谱及凝胶渗透色谱(GPC)等手段表征其结构,分子量及分子量分布。2、通过比旋光度([a]D),圆二色光谱(CD)考察了共聚物中,聚乙二醇单甲醚(MPEG)分子量,MPEG含量,甲醇含量,溶剂极性及时间五个因素对共聚物的光学活性和二级结构的影响。结果表明,共聚物polyacetylene—MPEG具有很强的光学活性且能形成单一方向的螺旋构象；随着MPEG分子量及含量的增加,共聚物的光学活性会降低；甲醇的存在会破坏共聚物螺旋结构的稳定性,且随着甲醇含量的逐渐增大,这种破坏性也会逐渐加大；在所选的四种溶剂中(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。3、考察了共聚物poly(1a80-co-3b20)在不同浓度(初始浓度：1mg·mL-1,0.2mg·mL-1)下不同溶剂体系(CHCl3/H2O, dioxane/H2O, THF/H2O)中的自组装行为,通过扫描电镜观察可知,在氢键及亲水／疏水作用驱动下,共聚物在相对较稀的溶液中易自组装成各种有序的微观结构,而在相对较浓的溶液中则不易自组装成有序的微观结构。更多还原

【Abstract】 People have interest in helical polymer due to ubiquitous nature helix structure. While only nature helical polymers self-assemble into high-level organizational structures and can play important roles in human life. Therefore, further study in the self-assembly of helical polymer is particularly important. In this paper, novel amphiphilic graftcopolymers were synthesized, and the self-assembly behavior of copolymers was studied. Detailed works were described as follows:1. The novel graftcopolymers of polyacetylene—MPEG (polyethylene glycol monomethyl ether) having C-chirality and hydrophilic macromolecule as pendant groups were synthesized via (nbd)Rh+[η6-C6H5B-(C6H5)3] as catalyst. The structure of copolymers was characterized by FT-IR. Moderate molecular weights (Mn) (13000-15000) and Mw/Mn (2.1-2.2) of copolymers were measured by GPC.2. The optical activity and secondary structure of the copolymers were characterized by specific rotations ([α]D) and circular dichroism (CD) spectra. Five factors(Mn of MPEQ amount of MPEQ methanol content, polarity of solvents, time) were observed to affect the helix structure of polymers. The results showed that the copolymers had optical activity and could form single helical conformation. The optical activitiy of copolymers decreased gradually as the Mn and amount of MPEG increased, also decreased as the time delayed and the methanol content increased. The helical conformation of the copolymers kept the better stability in CHCl3 comparing to other three selective solvents (THF, CH2C12, benzene).3. The assembly phenomenon of the poly(la80-co-3b20) was studied in different solvents systems(dioxane/H2O, CHCl3/H2O, THF/H2O) with different concentrations(initial concentration:1 mg·mL-1, 0.2mg·mL-1). By the SEM images of these systems, we could get conclusion that the copolymer could self-assemble into some orderly congeries in relatively dilute solvent-systems under the synergy effect of internal hydrogen bond-driven and external hydrophilic/hydrophobic-driven, while it is difficult to form orderly congeries in relatively dilute solvent-systems.更多还原