Unimolecular micelles from graft copolymer with binary side chains

RSC Advances ◽  
2016 ◽  
Vol 6 (64) ◽  
pp. 58871-58883 ◽  
Author(s):  
Yangmiao Mo ◽  
Shudong Lin ◽  
Yuanyuan Tu ◽  
Guojun Liu ◽  
Jiwen Hu ◽  
...  
Keyword(s):  
Graft Copolymer ◽  
Side Chains ◽  
Intramolecular Association

A novel amphiphilic binary graft copolymer was synthesized and used to prepare unimolecular micelles by intramolecular association.

Synthesis and characterization of amphiphilic graft copolymers with hydrophobic poly(α-methylstyrene) backbone and hydrophilic poly(n-vinylpyrrolidone) side chains

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Fatima Zohra Sebba ◽  
Seghier Ould Kada ◽  
Mohamed Benaicha ◽  
Nerjesse Nemiche
Keyword(s):  
Graft Copolymer ◽  
Graft Copolymers ◽  
Radical Copolymerization ◽  
Side Chains ◽  
Free Radical Copolymerization ◽  
Good Efficiency ◽  
Molecular Weights ◽  
Grafting Reaction ◽  
Viscosity Variation ◽  
End Capping

AbstractIn this study, 2-oxopropylmethacrylate-terminated poly(N-vinyl-2- pyrrolidone) is produced by cationic polymerization using HClO4 as an initiator. Termination (end capping) step is accomplished using 2- hydroxypropylmethacrylate (2HPMA) and the polymer product has different chain lengths of molecular weight averages ranging from 672 to 3049 g/mol. The study also synthesised amphipathic graft copolymers having hydrophobic poly(α- methylstyrene) as a backbone chain and hydrophilic poly(N-vinyl-2-pyrrolidone) (PVP) as side chains of various lengths. The copolymer synthesis was accomplished by free radical copolymerization of ω-oxopropylmethacrylate PVP in the presence of α-methyl styrene initiated with benzoyl peroxide. Measurements of the dynamic viscosity of the polymer solution (20% weight of macromonomers in ethanol) show that the viscosity is proportional to the average molecular weights M̅n . However, a reverse behaviour of the viscosity variation with regard to M̅n is observed for graft copolymer samples. The viscosity variation with respect to the graft copolymer mass must be due to steric effects, which are strongly pronounced in grafted copolymer chains. Appearance of the number of side chains attached to poly(α-methylstyrene) backbone reveals that the grafting reaction has occurred with good efficiency.

Spinning of Fibers from Graft Copolymers of Polyacrylonitrile and Poly(Methyl Acrylate)

1976 ◽  
Vol 46 (2) ◽  
pp. 77-81 ◽  
Author(s):  
Samy Abdel Monem El-Garf
Keyword(s):  
Graft Copolymer ◽  
Methyl Acrylate ◽  
Graft Copolymers ◽  
Coagulation Bath ◽  
Side Chains ◽  
Initial Value

Fibers were spun from graft copolymers of polyacrylonitrile and poly(methyl acrylate). Increasing poly(methyl acrylate) side chains from 5 to 8% decreased the viscosity of the spinning solution in dimethylformamide. The spinning solutions were unstable. When the graft copolymer contained 5% side chains, the viscosity of these solutions returned to almost its initial value by heating. Fibers were obtained from graft copolymers containing from 5–13% poly(methyl acrylate) side chains. These were formed at the temperature of the coagulation bath (50°C), while at temperatures less than 50°C the fibers were not obtained. Weak fibers were produced from a graft copolymer containing 13% side chains at the temperatures of the coagulation bath (20 and 50°C). No fibers were obtained from graft copolymer containing 25% side chains. The method of dissolution of the graft copolymers does affect the drawing of fibers produced from them. It was observed that the heating of the spinning solution decreases the amount of drawing of the produced fibers. The presence of the flexible side chains of poly(methyl acrylate) in the graft copolymer improves the maximum possible degree of drawing of the fibers relative to that of fibers from the initial linear copolymer and homopolyacrylonitrile.

The Effect of a Method of Dissolution of Graft Copolymer of Polyacrylonitrile and Poly(Methyl Acrylate) on Drawability and Properties of Spun Fibers

1976 ◽  
Vol 46 (10) ◽  
pp. 767-770
Author(s):  
Samy Abdel Monem El-Garf
Keyword(s):  
Graft Copolymer ◽  
Methyl Acrylate ◽  
Modulus Of Elasticity ◽  
Abrasion Resistance ◽  
Side Chains ◽  
Yarn Strength ◽  
Dissolution Temperature ◽  
Initial Modulus ◽  
Spun Fibers

It was found that dissolution of the graft copolymer has an effect on drawability and other properties of fibers spun from this graft copolymer. The resistance to double bending and abrasion resistance are considerably decreased with the increase of the dissolution temperature. The breaking properties were not greatly changed. The maximum loop and knotted yarn strength was reached when the polymer was dissolved by heating. These values are 100% and 99% of the original, respectively—higher than those obtained from PAN and PANM. The presence of 5% PMA in the side chains of the graft copolymer increased the flexibility of these chains. This is evident from the decrease of the initial modulus of elasticity from the values obtained for PANM and PAN.

The Mobility of Tryptophan and Dansyl Fluorophores in Labelled Poly(N-ethylacrylamide) and Poly(N-ethylmethacrylamide)

1993 ◽  
Vol 58 (10) ◽  
pp. 2383-2395 ◽  
Author(s):  
František Mikeš ◽  
Drahomír Výprachtický ◽  
Jan Pecka
Keyword(s):  
Conformational Changes ◽  
High Viscosity ◽  
Side Chains ◽  
Fluorescence Depolarization ◽  
Polymer Backbone ◽  
Short Side ◽  
Low Viscosity ◽  
Viscosity Range ◽  
Methylene Groups ◽  
Intramolecular Association

The mobility of tryptophan fluorophore in N-butyl-Nα-acetyltryptophanamide and in side chain of labelled poly(N-ethylacrylamide) and poly(N-ethylmethacrylamide) was investigated by the fluorescence depolarization method. The mobility of the fluorophore in the low-molecular-weight model is much higher than in side chains of the polymers. Different steric hindrance by the polymer backbone can explain the higher mobility of the fluorophore in poly(N-ethylacrylamide) and in poly(N-ethylmethacrylamide). The mobility of 5-dimethylamino-1-naphthalenesulfonamide (dansyl) fluorophore in side chains of labelled poly(N-ethylmethacrylamide) in the high-viscosity range increases with increasing number of methylene groups in side chains. The low-viscosity range, the rate s of conformational changes in short side chains (n = 2 - 7) are approximately constant and significantly decrease in long side chains (n = 10, 12). The drop in the rates is probably due to intramolecular association of the long hydrophobic chains in water.

Construction of semi-fluorinated amphiphilic graft copolymer bearing a poly(2-methyl-1,4-bistrifluorovinyloxybenzene) backbone and poly(ethylene glycol) side chains via the grafting-onto strategy

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 39668-39676 ◽  
Author(s):  
Guolin Lu ◽  
Hao Liu ◽  
Haifeng Gao ◽  
Chun Feng ◽  
Yongjun Li ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Graft Copolymer ◽  
Graft Copolymers ◽  
Side Chains ◽  
Poly Ethylene Glycol ◽  
Amphiphilic Graft Copolymer ◽  
Amphiphilic Graft Copolymers ◽  
Poly Ethylene ◽  
Williamson Reaction ◽  
Grafting Onto

Amphiphilic graft copolymers bearing a hydrophobic PMBTFVB backbone and hydrophilic PEG side chains were synthesized by Williamson reaction through the grafting-onto strategy.

scholarly journals Ultra-large sheet formation by 1D to 2D hierarchical self-assembly of a “rod–coil” graft copolymer with a polyphenylene backbone

2016 ◽  
Vol 7 (6) ◽  
pp. 1234-1238 ◽  
Author(s):  
Yinjuan Huang ◽  
Rui Yuan ◽  
Fugui Xu ◽  
Yiyong Mai ◽  
Xinliang Feng ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Graft Copolymer ◽  
Self Assembly ◽  
Side Chains ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Large Sheet

This study presents a unique ultra-large sheet formation through 1D to 2D hierarchical self-assembly of a rod–coil graft copolymer containing a rigid polyphenylene backbone tethered with flexible poly(ethylene oxide) side chains.

scholarly journals Synthesis, Structure, Hydrodynamics and Thermoresponsiveness of Graft Copolymer with Aromatic Polyester Backbone at Poly(2-isopropyl-2-oxazoline) Side Chains

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2643 ◽  
Author(s):  
Elena Tarabukina ◽  
Emil Fatullaev ◽  
Anna Krasova ◽  
Mikhail Kurlykin ◽  
Andrey Tenkovtsev ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Graft Copolymer ◽  
Graft Copolymers ◽  
Linear Chain ◽  
Terminal Group ◽  
Solution Temperature ◽  
Side Chains ◽  
Critical Solution Temperature ◽  
Copolymer Solution ◽  
Aromatic Polyester

New thermoresponsive graft copolymers with an aromatic polyester backbone and poly(2-isopropyl-2-oxazoline) (PiPrOx) side chains are synthesized and characterized by NMR and GPC. The grafting density of side chains is 0.49. The molar masses of the graft-copolymer, its backbone, side chains, and the modeling poly-2-isopropyl-2-oxaziline are 74,000, 19,000, 4300, and 16,600 g·mol−1, respectively. Their conformational properties in nitropropane as well as thermoresponsiveness in aqueous solutions are studied and compared with that of free side chains, i.e., linear PiPrOx with a hydrophobic terminal group. In nitropropane, the graft-copolymer adopts conformation of a 13-arm star with a core of a collapsed main chain and a PiPrOx corona. Similarly, a linear PiPrOx chain protects its bulky terminal group by wrapping around it in a selective solvent. In aqueous solutions at low temperatures, graft copolymers form aggregates due to interaction of hydrophobic backbones, which contrasts to molecular solutions of the model linear PiPrOx. The lower critical solution temperature (LCST) for the graft copolymer is around 20 °C. The phase separation temperatures of the copolymer solution were lower than that of the linear chain counterpart, decreasing with concentration for both polymers.

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