scholarly journals One-Step Photocontrolled Polymerization-Induced Self-Assembly (Photo-PISA) by Using In Situ Bromine-Iodine Transformation Reversible-Deactivation Radical Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 150 ◽  
Author(s):  
Haihui Li ◽  
Qinghua Xu ◽  
Xiang Xu ◽  
Lifen Zhang ◽  
Zhenping Cheng ◽  
...  

Polymerization-induced self-assembly (PISA) has become an effective strategy to synthesize high solid content polymeric nanoparticles with various morphologies in situ. In this work, one-step PISA was achieved by in situ photocontrolled bromine-iodine transformation reversible-deactivation radical polymerization (hereinafter referred to as Photo-BIT-RDRP). The water-soluble macroinitiator precursor α-bromophenylacetate polyethylene glycol monomethyl ether ester (mPEG1k-BPA) was synthesized in advance, and then the polymer nanomicelles (mPEG1k-b-PBnMA and mPEG1k-b-PHPMA, where BnMA means benzyl methacrylate and HPMA is hydroxypropyl methacrylate) were successfully formed from a PISA process of hydrophobic monomer of BnMA or HPMA under irradiation with blue LED light at room temperature. In addition, the typical living features of the photocontrolled PISA process were confirmed by the linear increase of molecular weights of the resultant amphiphilic block copolymers with monomer conversions and narrow molecular weight distributions (Mw/Mn < 1.20). Importantly, the photocontrolled PISA process is realized by only one-step method by using in situ photo-BIT-RDRP, which avoids the use of transition metal catalysts in the traditional ATRP system, and simplifies the synthesis steps of nanomicelles. This strategy provides a promising pathway to solve the problem of active chain end (C-I) functionality loss in two-step polymerization of BIT-RDRP.

2017 ◽  
Vol 8 (39) ◽  
pp. 6073-6085 ◽  
Author(s):  
Yan-an Wang ◽  
Yan Shi ◽  
Zhifeng Fu ◽  
Wantai Yang

A novel and highly efficient organic catalyst for the reversible-deactivation radical polymerization (RDRP) of methyl methacrylate with anin situformed alkyl iodide initiator.


2020 ◽  
Vol 11 (7) ◽  
pp. 1386-1392
Author(s):  
Chunyang Bao ◽  
Jing Chen ◽  
Die Li ◽  
Aotian Zhang ◽  
Qiang Zhang

Cu(0)-RDRP was first used for the polymerization-induced self-assembly of lipase–polymer conjugates, inducing the formation of nanospheres with preserved activity and degradability.


2015 ◽  
Vol 6 (36) ◽  
pp. 6509-6518 ◽  
Author(s):  
Mingmin Zhang ◽  
Michael F. Cunningham ◽  
Robin A. Hutchinson

Lowering the concentration of adsorbed radicals on the Cu(0) surface, achieved by reducing catalyst and adding NaBr, is the key to the synthesis of well-defined P(HEA) without a high molecular weight shoulder in aqueous solution using two-step Cu(0)in situmediation.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1947
Author(s):  
Fehaid M. Alsubaie ◽  
Othman Y. Alothman ◽  
Basheer A. Alshammari ◽  
Hassan Fouad

In this work, copper-mediated reversible deactivation radical polymerization (RDRP) of homo-polyacrylamides was conducted in aqueous solutions at 0.0 °C. Various degrees of polymerization (DP = 20, 40, 60, and 80) of well-defined water-soluble homopolymers were targeted. In the absence of any significant undesirable side reactions, the dispersity of polydiethylacrylamide (PDEA) and polydimethylacrylamide (PDMA) was narrow under controlled polymerization conditions. To accelerate the polymerization rate, disproportionation of copper bromide in the presence of a suitable ligand was performed prior to polymerization. Full conversion of the monomer was confirmed by nuclear magnetic resonance (NMR) analysis. Additionally, the linear evolution of the polymeric chains was established by narrow molecular weight distributions (MWDs). The values of theoretical and experimental number average molecular weights (Mn) were calculated, revealing a good matching and robustness of the system. The effect of decreasing the reaction temperature on the rate of polymerization was also investigated. At temperatures lower than 0.0 °C, the controlled polymerization and the rate of the process were not affected.


2020 ◽  
Vol 11 (47) ◽  
pp. 7497-7505
Author(s):  
Jiannan Cheng ◽  
Kai Tu ◽  
Enjie He ◽  
Jinying Wang ◽  
Lifen Zhang ◽  
...  

A novel strategy for preparing block copolymers with semifluorinated alternating copolymers as macroinitiators was established by photocontrolled iodine-mediated RDRP under irradiation with blue LED light at room temperature.


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