Synthesis of Ethyl Cellulose Grafted Poly(N-isopropylacrylamide) Copolymer and Its Micellization
文献类型：期刊论文
| 作者 | Kang Hongliang1; Liu Ruigang1; Huang Yong1,2 |
| 刊名 | ACTA CHIMICA SINICA
 |
| 出版日期 | 2013-01-15 |
| 卷号 | 71期号:1页码:114-120 |
| 关键词 | Ethyl Cellulose Poly(N-isopropylacrylamide) Single-electron Transfer Living Radical Polymerization (Set-lrp) Graft Polymerization Thermoresponsive |
| ISSN号 | 0567-7351 |
| DOI | 10.6023/A12100805 |
| 英文摘要 | Thermo-responsive graft copolymers, ethyl cellulose grafting poly(N-isopropylacrylamide) (EC-g-PNIPAm), were synthesized by single-electron transfer living radical polymerization (SET-LRP) in THF/methanol mixed solvent. Ethyl cellulose macro-initiators (EC-Br) for SET-LRP were synthesized by the esterification between the hydroxyl groups on EC backbones and 2-bromoisobutyryl bromides. The degree of substitution of the EC-Br macro-initiator was tailored by varying the feeding mole ratio of 2-bromoisobutyryl bromide to the hydroxyl group on ethyl cellulose. Three EC-Br macro-initiators with different Br substitutions were used as the macro-initiators and it was found that the converting degree of the initiator sites was efficient and the graft density of graft copolymer was controllable. The SET-LRP of NIPAm was efficient that the monomer conversion was above 60% within 25 h. The linear plot of In([M](0)/[M](t)) versus the conversion indicated that the reaction was living and controllable. The graft copolymers were characterized by means of gel permeation chromatography (GPC), H-1 NMR and FTIR spectroscopy. GPC peak of the graft copolymer became narrower and shifted to the low elution time with the increase of reactive time. The molecular weight of the side-chain linearly increased with the reaction time. EC-g-PNIPAm copolymers were typical amphiphilic graft copolymers, having the hydrophobic EC backbone and the hydrophilic PNIPAm side chains. They could be self-assembled and form stable micelles in a selective solvent, water. The micelles were in spherical shape with typical diameter around 100 nm. Rod-like and flower shaped particles were also observed, which was probably due to the fusion of the spherical shaped micelles. The structure of the spherical shaped micelles was that the EC backbone collapsed to form the core of the micelles and the hydrophilic PNIPAm chains stayed in the outside of the micelles to stabilize the micelles. Due to the thermoresponsive branch chains of PNIPAm, the micelles could shrink with rising temperature due to the collapses of the PNIPAm side chains. |
| 语种 | 英语 |
| WOS记录号 | WOS:000315605300015 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/54315]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Kang Hongliang |
| 作者单位 | 1.Chinese Acad Sci, Inst Chem, State Key Lab Polymer Phys & Chem, Beijing Natl Lab Mol Sci, Beijing 100190, Peoples R China 2.Chinese Acad Sci, Natl Engn Res Ctr Engn Plast, Tech Inst Phys & Chem, Beijing 100190, Peoples R China |
| 推荐引用方式 GB/T 7714 | Kang Hongliang,Liu Ruigang,Huang Yong. Synthesis of Ethyl Cellulose Grafted Poly(N-isopropylacrylamide) Copolymer and Its Micellization[J]. ACTA CHIMICA SINICA,2013,71(1):114-120. |
| APA | Kang Hongliang,Liu Ruigang,&Huang Yong.(2013).Synthesis of Ethyl Cellulose Grafted Poly(N-isopropylacrylamide) Copolymer and Its Micellization.ACTA CHIMICA SINICA,71(1),114-120. |
| MLA | Kang Hongliang,et al."Synthesis of Ethyl Cellulose Grafted Poly(N-isopropylacrylamide) Copolymer and Its Micellization".ACTA CHIMICA SINICA 71.1(2013):114-120. |
入库方式： OAI收割
来源：化学研究所
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