Formation of long sub-chain hyperbranched poly(methyl methacrylate) based on inhibited self-cyclization of seesaw macromonomers

2016 ◽  
Vol 7 (29) ◽  
pp. 4842-4851 ◽  
Author(s):  
Peng-Yun Li ◽  
Wei-Dong He ◽  
Sheng-Qi Chen ◽  
Xiao-Xia Lu ◽  
Jia-Min Li ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Click Reaction ◽  
High Concentration ◽  
Poly Methyl Methacrylate ◽  
Hyperbranched Poly

Well-defined hyperbranched PMMA almost without self-cyclization was obtained through a click reaction, facilitated by a high concentration, good solvent and disubstituted chain ends.

scholarly journals Stereoregular poly(methyl methacrylate) with double-clickable ω-end: synthesis and click reaction

2015 ◽  
Vol 6 (19) ◽  
pp. 3601-3607 ◽  
Author(s):  
Yasuhiro Kohsaka ◽  
Kazuki Yamamoto ◽  
Tatsuki Kitayama
Keyword(s):  
Methyl Methacrylate ◽  
Click Reaction ◽  
Poly Methyl Methacrylate

Stereoregular PMMAs carrying an orthogonally double-clickable end, for thiol–ene and azide–alkyne cycloadditions, were prepared via termination with propargyl α-(chloromethyl)acrylate.

A Potential New RAFT - Click Reaction or a Cautionary Note on the Use of Diazomethane to Methylate RAFT-synthesized Polymers

2011 ◽  
Vol 64 (4) ◽  
pp. 433 ◽  
Author(s):  
Ming Chen ◽  
Graeme Moad ◽  
Ezio Rizzardo
Keyword(s):  
Molecular Weight ◽  
Methyl Methacrylate ◽  
Room Temperature ◽  
Click Reaction ◽  
Raft Polymerization ◽  
Dipolar Cycloaddition ◽  
Low Molecular Weight ◽  
Similar Reaction ◽  
Poly Methyl Methacrylate ◽  
End Groups

It has been found that diazomethane undergoes a facile 1,3‐dipolar cycloaddition with both dithiobenzoate RAFT agents and the dithiobenzoate end‐groups of polymers formed by RAFT polymerization. Thus, 2‐cyanoprop‐2‐yl dithiobenzoate on treatment with diazomethane at room temperature provided a mixture of stereoisomeric 1,3‐dithiolanes in near quantitative (>95%) yield. A low‐molecular‐weight RAFT‐synthesized poly(methyl methacrylate) with dithiobenzoate end‐groups underwent similar reaction as indicated by immediate decolourization and a quantitative doubling of molecular weight. Higher‐molecular‐weight poly(methyl methacrylate)s were also rapidly decolourized by diazomethane and provided a product with a bimodal molecular weight distribution. Under similar conditions, the trithiocarbonate group does not react with diazomethane.

scholarly journals Synthesis of Poly(methyl methacrylate) Grafted Multiwalled Carbon Nanotubes via a Combination of RAFT and Alkyne-Azide Click Reaction

2019 ◽  
Vol 9 (3) ◽  
pp. 603 ◽  
Author(s):  
Wenzhong Ma ◽  
Yuchen Zhao ◽  
Zhiwei Zhu ◽  
Lingxiang Guo ◽  
Zheng Cao ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Chain Transfer ◽  
Click Reaction ◽  
Multiwalled Carbon ◽  
Poly Methyl Methacrylate ◽  
First Order ◽  
Pristine Mwcnts ◽  
First Order Kinetics ◽  
Molecular Weight Dependence ◽  
Reversible Addition

An efficient synthesis route was developed for the preparation of multiwalled carbon nanotube (MWCNT) nanohybrids using azide-terminated poly(methyl methacrylate) (PMMA) via a combination of reversible addition fragmentation chain transfer (RAFT) and the click reaction. A novel azido-functionalized chain transfer agent (DMP-N3) was prepared and subsequently employed to mediate the RAFT polymerizations of methyl methacrylate (MMA). The RAFT polymerizations exhibited first-order kinetics and a linear molecular weight dependence with the conversion. The kinetic results show that the grafting percentage of PMMA on the MWCNTs surface grows along with the increase of the reaction time. Even at 50 °C, the grafting rate of azide-terminated PMMA is comparatively fast in the course of the click reaction, with the alkyne groups adhered to MWCNTs in less than 24 h. The successful functionalization of PMMA onto MWCNT was proved by FTIR, while TGA was employed to calculate the grafting degree of PMMA chains (the highest GP = 21.9%). Compared with the pristine MWCNTs, a thicker diameter of the MWCNTs-g-PMMA was observed by TEM, which confirmed the grafted PMMA chain to the surface of nanotubes. Therefore, the MWCNTs-g-PMMA could be dispersed and stably suspended in water.

scholarly journals Fabrication of carbon nanospheres by the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) core–shell composite nanoparticles

2017 ◽  
Vol 8 ◽  
pp. 1897-1908 ◽  
Author(s):  
Dafu Wei ◽  
Youwei Zhang ◽  
Jinping Fu
Keyword(s):  
Heat Treatment ◽  
Methyl Methacrylate ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Core Shell ◽  
Carbon Nanospheres ◽  
High Concentration ◽  
Poly Methyl Methacrylate ◽  
Bet Specific Surface Area

Carbon nanospheres with a high Brunauer–Emmett–Teller (BET) specific surface area were fabricated via the pyrolysis of polyacrylonitrile–poly(methyl methacrylate) (PAN–PMMA) core–shell nanoparticles. Firstly, PAN–PMMA nanoparticles at high concentration and low surfactant content were controllably synthesized by a two-stage azobisisobutyronitrile (AIBN)-initiated semicontinuous emulsion polymerization. The carbon nanospheres were obtained after the PAN core domain was converted into carbon and the PMMA shell was sacrificed via the subsequent heat treatment steps. The thickness of the PMMA shell can be easily adjusted by changing the feeding volume ratio (FVR) of methyl methacrylate (MMA) to acrylonitrile (AN). At an FVR of 1.6, the coarse PAN cores were completely buried in the PMMA shells, and the surface of the obtained PAN–PMMA nanoparticles became smooth. The thick PMMA shell can inhibit the adhesion between carbon nanospheres caused by cyclization reactions during heat treatment. The carbon nanospheres with a diameter of 35–65 nm and a high BET specific surface area of 612.8 m2/g were obtained from the PAN–PMMA nanoparticles synthesized at an FVR of 1.6. The carbon nanospheres exhibited a large adsorption capacity of 190.0 mg/g for methylene blue, thus making them excellent adsorbents for the removal of organic pollutants from water.

Multisegmented Block Copolymers by 'Click' Coupling of Polymers Prepared by ATRP

2007 ◽  
Vol 60 (6) ◽  
pp. 400 ◽  
Author(s):  
Patricia L. Golas ◽  
Nicolay V. Tsarevsky ◽  
Brent S. Sumerlin ◽  
Lynn M. Walker ◽  
Krzysztof Matyjaszewski
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Butyl Acrylate ◽  
Click Reaction ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Propargyl Ether ◽  
Click Coupling

Multisegmented block copolymers were prepared by the step-growth click coupling of well-defined block copolymers synthesized by atom transfer radical polymerization (ATRP). α,ω-Diazido-terminated polystyrene-block-poly(ethylene oxide)-block-polystyrene was coupled with propargyl ether in N,N-dimethylformamide in the presence of a CuBr/N,N,N´,N´´,N´´-pentamethyldiethylenetriamine catalyst. The preparation of multisegmented block copolymers was also demonstrated by the click coupling of propargyl ether with another diazido-terminated triblock copolymer, poly(n-butyl acrylate)-block-poly(methyl methacrylate)-block-poly(n-butyl acrylate), and a diazido-terminated pentablock copolymer, polystyrene-block-poly(n-butyl acrylate)-block-poly(methyl methacrylate)-block-poly(n-butyl acrylate)-block-polystyrene. The formation of a product of higher molecular weight and broader molecular weight distribution was verified by triple-detection size exclusion chromatography, which revealed that typically five to seven block copolymers were linked together during the click reaction. Differential scanning calorimetry and dynamic mechanical analysis revealed that the amphiphilic block copolymer behaves as a viscoelastic fluid, while its corresponding multiblock copolymer is an elastic material. The multisegmented block copolymers with partially miscible segments exhibit higher glass transition temperatures than their precursors.

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