排序方式: 共有18条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
RAFT聚合制备结构明确的荧光标识聚甲基丙烯酸甲酯 总被引:1,自引:0,他引:1
以铁氰化钾为氧化剂,通过N-咔唑二硫代甲酸钠的水相氧化制备了高纯度的中间体二硫化双(N-咔唑硫代甲酰)(DTCD),DTCD以晶体的形式从水中析出,提纯简单,性质稳定.通过DTCD与偶氮二异丁腈(AIBN)或偶氮二氰基戊酸(ACVA)的反应合成了2种性能优异的叔丁腈酯基RAFT试剂,N-咔唑二硫代甲酸异丁腈酯(CYCBD)和N-咔唑二硫代甲酸氰基戊酸(CVCBD),新合成工艺的副反应和杂质被大量减少,最终产物的收率可达80%以上.以CYCBD和CVCBD为可逆加成断裂链转移(RAFT)试剂,研究了它们对甲基丙烯酸甲酯(MMA)RAFT聚合的控制能力,结果表明CYCBD和CVCBD是性能优异的RAFT试剂,可以很好地用于制备结构明确、分子量分布窄的链末端咔唑标记的聚甲基丙烯酸甲酯(CPMMA),由它们所制得的CPMMA的PDI小于1.2.研究结果还表明CYCBD和CVCBD及由其合成的CPMMA在四氢呋喃(THF)溶液中具有显著的荧光特性,CPMMA在358nm处有很强的荧光发射峰,而且,在浓度范围为0.1~20μmol/L的THF溶液中,CPMMA的荧光发射强度与其浓度具有良好的线性关系.通过CYCBD和CVCBD可以方便地制备结构明确且具荧光标识的功能聚合物。 相似文献
7.
Anjie Dong Yinglei Zhai Li Xiao Haiying Qi Qi Tian Liandong Deng Ruiwei Guo 《Journal of Polymer Science.Polymer Physics》2010,48(5):503-508
The poly(ethylene glycol)/poly(2‐(N,N‐dimethylamino)ethyl methacrylate) (PEG/PDMAEMA) double hydrophilic block copolymers were synthesized by atom transfer radical polymerization using mPEG‐Br or Br‐PEG‐Br as macroinitiators. The narrow molecular weight distribution of PEG/PDMAEMA block copolymers was identified by gel permeation chromatography results. The thermosensitivity of PEG/PDMAEMA block copolymers in aqueous solution was revealed to depend significantly on pH, ionic strength, chain structure, and concentration of the block copolymers. By optimizing these factors, the cloud point temperature of PEG/PDMAEMA block copolymers can be limited within body temperature range (30–37 °C), which suggests that PEG/PDMAEMA block copolymers could be a good candidate for drug delivery systems. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 503–508, 2010 相似文献
8.
There were two famous conjectures on complete affine maximal surfaces, one due to Calabi, the other to Chern. Both were solved with different methods about one decade ago by studying the associated Euler-Lagrange equation. Here we survey recent developments and techniques in the study of certain Monge-Ampère equations associated with Chern??s Affine Bernstein Conjecture, in particular two of its proofs in our recent monograph (Li et?al. in Affine Bernstein problems and Monge-Ampère equations, 2010). In addition, we add some details of the proofs of auxiliary material that were omitted in (Li et?al. in Affine Bernstein problems and Monge-Ampère equations, 2010). The related background information is provided in the Introduction. 相似文献
9.
Xingxiao LI 《数学年刊B辑(英文版)》2022,43(3):473-482
In this paper, the authors give a characterization theorem for the standard tori S1(a) × S1(b), a, b > 0, as the compact Lagrangian ξ-submanifolds in the two-dimensional complex Euclidean space C2 , and obtain the best version of a former rigidity theorem for compact Lagrangian ξ-submanifold in C2 . Furthermore, their argument in this paper also proves a new rigidity theorem which is a direct generalization of a rigidity theorem by Li and Wang for Lagrangian self-shrinkers in C2. 相似文献
10.