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.

scholarly journals Two-dimensional chromatography of complex polymers. 3. Full analysis of polystyrene-poly(methyl methacrylate) diblock copolymers

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Harald Pasch ◽  
Kibret Mequanint ◽  
Adrian Jörg
Keyword(s):  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Diblock Copolymers ◽  
Size Exclusion ◽  
Molecular Heterogeneity ◽  
Two Dimensional ◽  
Poly Methyl Methacrylate ◽  
Mass Distributions ◽  
Exclusion Chromatography ◽  
Complex Polymers

AbstractPoly(styrene-block-methyl methacrylate)s were fully analyzed by liquid chromatography at the critical point of adsorption (LC-CC) and two-dimensional chromatography. Operating at chromatographic conditions corresponding to the critical points of the homopolymers polystyrene and poly(methyl methacrylate), the block lengths distributions for the different blocks of the block copolymers were determined quantitatively. Information on the amounts and molar mass distributions of homopolymers and coupling products that were identified in the samples as by-products was obtained by on-line coupled 2D chromatography. It was shown that a complete picture of the molecular heterogeneity of block copolymers can be obtained only when information from different chromatographic experiments is combined. Size exclusion chromatography alone is inappropriate for evaluating the molecular heterogeneity of such samples.

Synthesis and thermal properties of triblock copolymers of methyl methacrylate using combination of anionic and controlled radical polymerization: Poly(methyl methacrylate) center block bearing different microstructures

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhengji Song ◽  
Carole Pelletier ◽  
Yinghua Qi ◽  
Jasim Ahmed ◽  
Sunil K. Varshney ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Triblock Copolymers ◽  
Controlled Radical Polymerization ◽  
Alkyl Methacrylate ◽  
Poly Methyl Methacrylate ◽  
H Nmr

AbstractABA and/or ABC type triblock copolymers were synthesized by living anionic and controlled radical polymerization in which poly(methyl methacrylate) was used as central block. The structural composition of these block copolymers were determined by 1H NMR. The block length/molecular weight and microstructure of these polymers were measured by SEC. The microstructure of resultant central alkyl methacrylate block can be tailored from highly syndiotactic to highly isotactic structure by varying the solvent and/or initiator. The thermal and rheological properties of center poly(methyl methacrylate) block and poly(styreneb- methyl methacrylate-b- styrene) tri block copolymers were studied in detail.

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.

Investigation of the effect of mesoporous diatomaceous earth particles on RATRP of styrene and butyl acrylate

2018 ◽  
Vol 32 (2) ◽  
pp. 248-266 ◽  
Author(s):  
Khezrollah Khezri ◽  
Hassan Alijani ◽  
Yousef Fazli ◽  
Zahra Shariatinia
Keyword(s):  
Molecular Weight ◽  
Butyl Acrylate ◽  
Nitrogen Adsorption ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Transmission Electron ◽  
Exclusion Chromatography ◽  
Adsorption Desorption ◽  
Mesoporous Diatomite Nanoplatelets

Mesoporous diatomite nanoplatelets were employed to prepare various poly (styrene-co-butyl acrylate)/diatomite nanocomposites by in situ reverse atom transfer radical polymerization of styrene and butyl acrylate. Fourier-transform infrared spectroscopy, thermogravimetric analysis (TGA), and nitrogen adsorption/desorption isotherm were employed for evaluating some properties of the pristine diatomite nanoplatelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Addition of 3 wt% pristine mesoporous diatomite nanoplatelets leads to an increase in conversion from 77% to 92%. Molecular weight of poly (styrene-co-butyl acrylate) chains increases from 17,348 g mol−1 to 21,346 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite nanoplatelets; however, polydispersity index values increases from 1.38 to 1.65. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 35.5°C to 39.4°C with the addition of 3 wt% mesoporous diatomite nanoplatelets.

scholarly journals Degradation of ultra-high molecular weight poly(methyl methacrylate-co-butyl acrylate-co-acrylic acid) under ultra violet irradiation

RSC Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 112-120 ◽  
Author(s):  
R. Shanti ◽  
A. N. Hadi ◽  
Y. S. Salim ◽  
S. Y. Chee ◽  
S. Ramesh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
High Molecular Weight ◽  
Butyl Acrylate ◽  
Ultra Violet ◽  
Seeded Emulsion Polymerization ◽  
Poly Methyl Methacrylate ◽  
Ultra High Molecular Weight ◽  
High Molecular Weight Poly

A new acrylic terpolymer, poly(methyl methacrylate-co-butyl acrylate-co-acrylic acid) [P(MMA-co-BA-co-AA)] of ultra-high molecular weight (UHMW) was synthesizedviaseeded emulsion polymerization.

Synthesis of poly(methyl methacrylate) and block copolymers by semi-batch nitroxide mediated polymerization

2016 ◽  
Vol 7 (45) ◽  
pp. 6964-6972 ◽  
Author(s):  
N. Ballard ◽  
A. Simula ◽  
M. Aguirre ◽  
J. R. Leiza ◽  
S. van Es ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Polymer Structure ◽  
Solution Polymerization ◽  
Poly Methyl Methacrylate ◽  
Nitroxide Mediated Polymerization

The limits of control of the molecular weight and polymer structure in the semi-batch solution polymerization of methyl methacrylate by NMP are explored.

Synthesis and Characterization of Poly (styrene-co-butyl acrylate)/Silica Aerogel Nanocomposites by in situ AGET ATRP: Investigating Thermal Properties

2017 ◽  
Vol 36 (10) ◽  
pp. 955-962 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Molecular Weight ◽  
Butyl Acrylate ◽  
Silica Aerogel ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Molar Ratio ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Exclusion Chromatography

AbstractHydrophilic silica aerogel nanoparticles surface was modified with hexamethyldisilazane. Then, the resultant modified nanoparticles were used in random copolymerization of styrene and butyl acrylate via activators generated by electron transfer for atom transfer radical polymerization. Conversion and molecular weight determinations were performed using gas and size exclusion chromatography respectively. Addition of modified nanoparticles by 3 wt% results in a decrease of conversion from 68 to 46 %. Molecular weight of copolymer chains decreases from 12,500 to 7,500 g.mol–1 by addition of 3 wt% modified nanoparticles; however, PDI values increase from 1.1 to 1.4. Proton nuclear magnetic resonance spectroscopy results indicate that the molar ratio of each monomer in the copolymer chains is approximately similar to the initial selected mole ratio of them. Increasing thermal stability of the nanocomposites is demonstrated by thermal gravimetric analysis. Differential scanning calorimetry also shows a decrease in glass transition temperature by increasing modified silica aerogel nanoparticles.

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