Synthesis of RAFT Block Copolymers in a Multi-Stage Continuous Flow Process Inside a Tubular Reactor

2013 ◽  
Vol 66 (2) ◽  
pp. 192 ◽  
Author(s):  
Christian H. Hornung ◽  
Xuan Nguyen ◽  
Stella Kyi ◽  
John Chiefari ◽  
Simon Saubern

This work describes a multi-stage continuous flow polymerisation process for the synthesis of block copolymers using the RAFT polymerization method. The process retains all the benefits and versatility of the RAFT method and has been adapted for a series of monomer combinations, including acrylates, acrylamides, and vinyl monomers. It resulted in polymers with molecular weights between 13500 and 34100 g mol–1, and dispersities typically between 1.21 and 1.58. Different architectures were prepared (including combinations of hydrophilic and hydrophobic blocks) which are soluble in a range of different solvents including aqueous and organic media.

2020 ◽  
Vol 11 (12) ◽  
pp. 2080-2088
Author(s):  
Yingjie Wang ◽  
Mengqi Wang ◽  
Liangjiu Bai ◽  
Lifen Zhang ◽  
Zhenping Cheng ◽  
...  

Well-defined PNVP block copolymers with more-activated monomers were synthesized by a single RAFT polymerization method under irradiation with visible light at room temperature.


2019 ◽  
Vol 4 (10) ◽  
pp. 1854-1860
Author(s):  
Niraj K. Vishwakarma ◽  
Yoon-Ho Hwang ◽  
Avnish Kumar Mishra ◽  
Jin Kon Kim ◽  
Dong-Pyo Kim

Accelerated Cu(0)-mediated homo-/block (co)polymerization of the vinyl monomers is conducted via continuous-flow process with a copper metal-wire catalyst threaded through perfluoroalkoxy alkane (PFA) tube.


2020 ◽  
Vol 11 (45) ◽  
pp. 7244-7252
Author(s):  
Shiyuan Zhou ◽  
Peiyang Gu ◽  
Haibo Wan ◽  
Yutao Zhu ◽  
Anna Wang ◽  
...  

Two AIE block copolymers termed P1 and P2 bearing TPE and PEG-based chains were synthesized with moderate molecular weights and narrow PDIs via RAFT polymerization. Both P1 and P2 can be used in the fluorescence detection of nitroaromatic compounds (NACs) and cell images.


2017 ◽  
Vol 8 (39) ◽  
pp. 6024-6027 ◽  
Author(s):  
Na Li ◽  
Dongdong Ding ◽  
Xiangqiang Pan ◽  
Zhengbiao Zhang ◽  
Jian Zhu ◽  
...  

Stereo-triblock copolymers of poly(vinyl acetate) are synthesized with controlled molecular weights based on a temperature-programed photo-induced RAFT in HFIP.


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

2021 ◽  
Vol 69 (4) ◽  
Author(s):  
Tobias A. Gmür ◽  
Joydeb Mandal ◽  
Juliette Cayer-Barrioz ◽  
Nicholas D. Spencer

AbstractTo meet the need for oil-compatible friction modifier additives that can significantly reduce energy consumption in the boundary-lubrication regime, a macromolecular design approach has been taken. The aim was to produce a lubricious polymer film on the sliding surfaces. A series of readily functionalizable block copolymers carrying an oleophilic poly(dodecyl methacrylate) block and a functionalizable poly(pentafluorophenyl methacrylate) block of various lengths was synthesized by means of reversible addition-fragmentation chain-transfer (RAFT) polymerization. The poly(pentafluorophenyl methacrylate) block was used to attach surface-active nitrocatechol anchoring groups to the polymer. The friction-reduction properties of these polymers were assessed with 0.5 wt% solutions in hexadecane by means of rolling-sliding macroscopic tribological tests. Block copolymers with roughly equal block lengths and moderate molecular weights were significantly more effective at friction reduction than all other architectures investigated. They also displayed lower friction coefficients than glycerol monooleate—a commercially used additive. The film-formation ability of these polymers was examined using a quartz-crystal microbalance with dissipation (QCM-D), by monitoring their adsorption onto an iron oxide-coated QCM crystal. The polymer with highest lubrication efficiency formed a thin film of ~ 17 nm thickness on the crystal, indicating the formation of a polymer brush. Interferometric rolling-sliding experiments with the same polymer showed a separating film thickness of ~ 20 nm, which is consistent with the QCM-D value, bearing in mind the compression of the adsorbed layers on the two sliding surfaces during tribological testing. Graphical Abstract


2006 ◽  
Vol 59 (10) ◽  
pp. 749 ◽  
Author(s):  
Brad S. Lokitz ◽  
Jonathan E. Stempka ◽  
Adam W. York ◽  
Yuting Li ◽  
Hitesh K. Goel ◽  
...  

Chiral homo- and block copolymers based on the enantiomeric monomers N-acryloyl-l-alanine (ALAL) and N-acryloyl-d-alanine (ADAL) were prepared directly in water using controlled reversible addition–fragmentation chain transfer (RAFT) polymerization. The polymerization of the chiral monomers proceeded in a controlled fashion producing the respective homopolymers, block copolymers, and a statistical copolymer with targeted molecular weights and narrow molecular weight distributions. The chiroptical activity of these biomimetic polymers and their analogous model compounds was investigated using circular dichroism (CD). P(ALAL) and P(ADAL) were shown to be optically active exhibiting mirror image CD spectra. In addition, statistical and enantiomeric block copolymers prepared at 1:1 stochiometric ratios exhibited virtually no optical activity.


2010 ◽  
Vol 88 (3) ◽  
pp. 228-235 ◽  
Author(s):  
Chih-Feng Huang ◽  
Jeong Ae Yoon ◽  
Krzysztof Matyjaszewski

Amphiphilic block copolymers poly(N-vinylcarbazole)-b-poly(N-vinylpyrrolidone) (PNVK-b-PNVP) were prepared by xanthate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization. Both the PNVK and PNVP macroinitiators and the resulting block copolymers had molecular weights close to theoretical values, predicted for efficient initiation, in the range of Mn = 30 000 to 90 000. The block copolymers dissolved in several organic solvents but, depending on their composition, in methanol formed either micelles or large aggregates, as confirmed by dynamic light scattering. The presence of globular aggregates was confirmed by tapping mode atomic force microscopy.


2019 ◽  
Vol 10 (16) ◽  
pp. 2064-2072 ◽  
Author(s):  
Jinying Peng ◽  
Qinghua Xu ◽  
Yuanyuan Ni ◽  
Lifen Zhang ◽  
Zhenping Cheng ◽  
...  

A fast visible light controlled RAFT polymerization system without the prior removal of oxygen was successfully carried out in a continuous tubular reactor with water as a green solvent.


2021 ◽  
Author(s):  
Tobias A. Gmür ◽  
Joydeb Mandal ◽  
Juliette Cayer-Barrioz ◽  
Nicholas D. Spencer

Abstract In the search for new, oil-compatible friction-modifier additives that can significantly reduce energy consumption by reducing the friction in the boundary-lubrication regime, a macromolecular-design approach has been taken. This involved the synthesis of a series of readily functionalizable block copolymers carrying an oleophilic poly(lauryl methacrylate) block and a functionalizable poly(pentafluorophenyl methacrylate) block of various lengths by means of reversible addition-fragmentation chain-transfer (RAFT) polymerization. The poly(pentafluorophenyl methacrylate) block was used to attach surface-active nitro-catechol anchoring groups to the polymer. The friction-reduction properties of these polymers were assessed using 0.5 wt.% solutions in hexadecane using rolling-sliding macroscopic tribological tests. Block copolymers with roughly equal block lengths and moderate molecular weights were significantly more effective at friction reduction than all other architectures investigated. They also displayed lower friction coefficients than glycerol monooleate, a commercially used additive. The film formation ability of these polymers was examined using a quartz-crystal microbalance with dissipation (QCM-D), by monitoring their adsorption onto an iron-oxide coated QCM crystal. The polymer with highest lubrication efficiency formed a thin film of ∼17 nm thickness on the iron-oxide coated QCM crystal, consistent with the formation of a polymer brush. Interferometric rolling-sliding experiments with the same polymer showed a separating film thickness of ∼20 nm, which is consistent with the QCM-D value, bearing in mind the compression of the adsorbed layers on the two sliding surfaces during tribological testing.


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