One‐step synthesis of block copolymers using a hydroxyl‐functionalized trithiocarbonate RAFT agent as a dual initiator for RAFT polymerization and ROP

2012 ◽  
Vol 51 (4) ◽  
pp. 774-779 ◽  
Author(s):  
Hyun Uk Kang ◽  
Young Chang Yu ◽  
Sang Jin Shin ◽  
Ji Ho Youk
Polymer ◽  
2014 ◽  
Vol 55 (23) ◽  
pp. 5986-5990 ◽  
Author(s):  
Young Chang Yu ◽  
Hang Sung Cho ◽  
Woong-Ryeol Yu ◽  
Ji Ho Youk

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5147
Author(s):  
Wanting Hou ◽  
Ruiqi Liu ◽  
Siwei Bi ◽  
Qian He ◽  
Haibo Wang ◽  
...  

Due to a strong retardation effect of o-nitrobenzyl ester on polymerization, it is still a great challenge to prepare amphiphilic block copolymers for polymersomes with a o-nitrobenzyl ester-based hydrophobic block. Herein, we present one such solution to prepare amphiphilic block copolymers with pure poly (o-nitrobenzyl acrylate) (PNBA) as the hydrophobic block and poly (N,N’-dimethylacrylamide) (PDMA) as the hydrophilic block using bulk reversible addition-fragmentation chain transfer (RAFT) polymerization of o-nitrobenzyl acrylate using a PDMA macro-RAFT agent. The developed amphiphilic block copolymers have a suitable hydrophobic/hydrophilic ratio and can self-assemble into photoresponsive polymersomes for co-loading hydrophobic and hydrophilic cargos into hydrophobic membranes and aqueous compartments of the polymersomes. The polymersomes demonstrate a clear photo-responsive characteristic. Exposure to light irradiation at 365 nm can trigger a photocleavage reaction of o-nitrobenzyl groups, which results in dissociation of the polymersomes with simultaneous co-release of hydrophilic and hydrophobic cargoes on demand. Therefore, these polymersomes have great potential as a smart drug delivery nanocarrier for controllable loading and releasing of hydrophilic and hydrophobic drug molecules. Moreover, taking advantage of the conditional releasing of hydrophilic and hydrophobic drugs, the drug delivery system has potential use in medical applications such as cancer therapy.


RSC Advances ◽  
2015 ◽  
Vol 5 (20) ◽  
pp. 15461-15468 ◽  
Author(s):  
Bishnu P. Koiry ◽  
Arindam Chakrabarty ◽  
Nikhil K. Singha

Preparation of an amphiphilic block copolymer (Am-BCP) based on poly(ethylene glycol) methyl ether methacrylate (PEGMA) and heptafluorobutyl acrylate (HFBA) via RAFT polymerization and application of this Am-BCP as surf-RAFT agent for polymerization of styrene.


2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Wenwen Yu ◽  
Lijing Zhu ◽  
Jiangao Shi ◽  
Cunting Zhao

Poly(lactic acid)-block-poly(N,N-dimethylaminoethyl methacrylate) (PLA-PDMAEMA) copolymers were synthesized from aminolyzed PLA via reversible addition fragmentation (RAFT) polymerization. PLA undergoes aminolytic degradation with ethylenediamine (EDA). The kinetics of the aminolysis reaction of PLA at different temperatures and EDA concentrations was investigated in detail. The molar masses of products rapidly decreased in the initial stage at low aminolytic degree. Meanwhile, reactive –NH2 and –OH groups were introduced to the end of shorter PLA chains and used as sites to further immobilize the RAFT agent. PLA-PDMAEMA block copolymers were synthesized. A pseudo-first-order reaction kinetics was observed for the RAFT polymerization of PDMAEMA at a low conversion. By controlling the aminolysis reaction of PLA and RAFT polymerization degree of DMAEMA, the length distributions of the PLA and PDMAEMA blocks can be controlled. This method can be extended to more systems to obtain block copolymers with controllable block structure.


2013 ◽  
Vol 66 (12) ◽  
pp. 1564 ◽  
Author(s):  
Lily A. Dayter ◽  
Kate A. Murphy ◽  
Devon A. Shipp

A single reversible addition–fragmentation chain transfer (RAFT) agent, malonate N,N-diphenyldithiocarbamate (MDP-DTC) is shown to successfully mediate the polymerization of several monomers with greatly differing reactivities in radical/RAFT polymerizations, including both vinyl acetate and styrene. The chain transfer constants (Ctr) for MDP-DTC for both these monomers were evaluated; these were found to be ~2.7 in styrene and ~26 in vinyl acetate, indicating moderate control over styrene polymerization and good control of vinyl acetate polymerization. In particular, the MDP-DTC RAFT agent allowed for the synthesis of block copolymers of these two monomers without the need for protonation/deprotonation switching, as has been previously developed with N-(4-pyridinyl)-N-methyldithiocarbamate RAFT agents, or other end-group transformations. The thermal properties of the block copolymers were studied using differential scanning calorimetry, and those with sufficiently high molecular weight and styrene composition appear to undergo phase separation. Thus, MDP-DTC may be useful for the production of other block copolymers consisting of monomers with highly dissimilar reactivities.


2014 ◽  
Vol 52 (11) ◽  
pp. 1607-1613 ◽  
Author(s):  
Sang Jin Shin ◽  
Young Chang Yu ◽  
Ja Deok Seo ◽  
Sung Ju Cho ◽  
Ji Ho Youk

2018 ◽  
Vol 130 (14) ◽  
pp. 3655-3659 ◽  
Author(s):  
Yong Wang ◽  
Yajun Zhao ◽  
Yunsheng Ye ◽  
Haiyan Peng ◽  
Xingping Zhou ◽  
...  

Polymer ◽  
2016 ◽  
Vol 87 ◽  
pp. 108-113 ◽  
Author(s):  
Munhyung Kang ◽  
Soo Young Lee ◽  
Hwan Ho Shin ◽  
Young Chang Yu ◽  
Ji Ho Youk

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