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.

Synthesis of Poly(acrylamide-Methacrylate)-G-Octylphenyl Polyoxyethylene and its Micellar Behavior in Aqueous Solution

2011 ◽  
Vol 239-242 ◽  
pp. 3337-3341
Author(s):  
Dong Xia Zhang ◽  
Wen Hui Hu ◽  
Fang Ping Wang ◽  
Lin Ke Xue ◽  
Xin Zhen Du
Keyword(s):  
Aqueous Solution ◽  
Graft Copolymer ◽  
Main Chain ◽  
Radical Copolymerization ◽  
Molar Ratio ◽  
Free Radical Copolymerization ◽  
Transmission Electron ◽  
Spherical Micelles ◽  
Acrylamide Monomer ◽  
Poly Acrylamide

An amphiphilic graft copolymer with poly(acrylamide-methacrylate) as a main chain and octylphenyl polyoxyethylene as side chains (P(AM-MA)-g-C8PhEO10) was successfully synthesized via free radical copolymerization. The structure and the composition of the graft copolymer were characterized by FTIR, 1H-NMR and elemental analysis (EA) in detail. The absolute molecular weight of the copolymer is 1.304×106, as determined by static light scattering (SLS). The molar ratio of acrylamide monomer to the macromonomer is 33:1 in the copolymer and 53 C8PhEO10 branch chains attach to a P(AM-MA) backbone. The micellar behavior of P(AM-MA)-g-C8PhEO10 was preliminarily studied by means of surface tension measurements, transmission electron microscope (TEM) in aqueous solution. It was found that the stable spherical micelles with core-shell structure are formed and polymolecular micelles are larger and more compact than monomolecular micelles. In addition, the graft copolymer has favorable thermal stability.

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.

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 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.

Syntheses and interfacial characterization of graft copolymers from styrene and 2-hydroxyethyl methacrylate that comprise either trunks or branches

1995 ◽  
Vol 73 (11) ◽  
pp. 1757-1764 ◽  
Author(s):  
Hidekazu Yoshida ◽  
Shinichi Itsuno ◽  
Koichi. Ito
Keyword(s):  
Graft Copolymer ◽  
Graft Copolymers ◽  
Micelle Formation ◽  
Hydroxyethyl Methacrylate ◽  
H Nmr ◽  
Copolymer Films ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Copolymer Micelle ◽  
End Capping

Polystyrene (PS) and poly(2-hydroxyethyl methacrylate) (PHEMA) macromonomers with either p-vinylbenzyl or methacrylate end groups were prepared by living anionic polymerizations of styrene and 2-(trimethylsilyloxy)ethyl methacrylate, respectively, followed by appropriate end-capping. They were radically copolymerized with 2-hydroxyethyl methacrylate and styrene, respectively, to afford PS-g-PHEMA and PHEMA-g-PS, having PS trunks with PHEMA branches or the reverse architecture. 1H NMR spectra of the graft copolymers in deuterated methanol showed their micelle formation with PS and PHEMA chains as the core and the shell, respectively. In chloroform the reverse micelles were observed. Contact angle measurements of water on the graft copolymer films revealed that PS chains were generally dominant on the free surface. The films either cast from methanol or after immersion into water, however, were apparently wettable, indicating dominant PHEMA chains on the surface. Keywords: styrene, 2-hydroxyethyl methacrylate, graft copolymer, micelle formation, wettability.

Determining chemospecificity in reactions with chain transfer agent and corresponding radical via evaluation of molecular weight dependency of apparent comonomer reactivity ratios: free-radical copolymerization of vinyl acetate and dibutyl maleate

RSC Advances ◽  
2016 ◽  
Vol 6 (111) ◽  
pp. 109759-109768 ◽  
Author(s):  
Seyed Saeid Rahdar ◽  
Mahdi Abdollahi ◽  
Ebrahim Ahmadi ◽  
Abbas Biglari
Keyword(s):  
Molecular Weight ◽  
Free Radical ◽  
Chain Transfer ◽  
Radical Copolymerization ◽  
Reactivity Ratios ◽  
Free Radical Copolymerization ◽  
Molecular Weights ◽  
Radical Reactivity ◽  
Dibutyl Maleate ◽  
Trichloromethyl Radical

Performing copolymerization with two different conditions leading to different molecular weights allows us to determine trichloromethyl radical reactivity towards comonomers.

Synthesis and Properties of Copolymer of p-Hydroxybenzoic Acid and Sulfanilic Acid Using Horseradish Peroxidase

2012 ◽  
Vol 487 ◽  
pp. 687-691
Author(s):  
Sheng Hua Lv ◽  
Gong Rui ◽  
Di Li
Keyword(s):  
Free Radical ◽  
Horseradish Peroxidase ◽  
Reaction Temperature ◽  
Graft Copolymer ◽  
Sulfanilic Acid ◽  
Radical Copolymerization ◽  
Hydroxybenzoic Acid ◽  
Free Radical Copolymerization ◽  
Shrinkage Temperature ◽  
Increment Ratio

A novel copolymer of p-hydroxybenzoic acid and sulfanilic acid (pHBA-SAA copolymer) was synthesized by free radical copolymerization with horseradish peroxidase (HRP)/HB2BOB2B as initiator. The effects of the proportion of monomers, the amount of catalyst, reaction temperature and time on copolymer performance were investigated. The structure of the copolymer was characterized with FTIR, NMR and GPC. Shrinkage temperature (TBsB) of the leather tanned with the copolymer was 81.5°C. The thickness increment ratio of the retanned leather was 23.23% and meanwhile the retanned leather showed better softness and exceptionally good flexible. The results indicated that the graft copolymer has excellent retanning properties and particularly suited to be served as retannage substitute for chrome and resin retannages in making leather process.

Waterborne UV-curable comb-shaped (meth)acrylate graft copolymer containing long fluorinated and/or polysiloxane side chains

RSC Advances ◽  
2016 ◽  
Vol 6 (41) ◽  
pp. 34364-34375 ◽  
Author(s):  
Jianquan Tan ◽  
Weiqu Liu ◽  
Zhengfang Wang
Keyword(s):  
Graft Copolymer ◽  
Graft Copolymers ◽  
Side Chains ◽  
Uv Curable

Waterborne UV-curable comb-shaped (meth)acrylate graft copolymers containing long fluorinated and/or siloxane side chains.

Influence of Ionic Liquids on the Free Radical Copolymerization of Styrene with Acrylonitrile

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Inga Woecht ◽  
Gudrun Schmidt-Naake
Keyword(s):  
Ionic Liquids ◽  
Free Radical ◽  
Radical Copolymerization ◽  
Polymerization Rate ◽  
Dimethyl Formamide ◽  
Copolymer Composition ◽  
Free Radical Copolymerization ◽  
Molecular Weights ◽  
Monomer Feed ◽  
Dibenzoyl Peroxide

AbstractFree radical copolymerization of styrene (S) and acrylonitrile (AN) in the ionic liquids (ILs) 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6), 1,3-dimethylimidazolium dimethylphosphate ([MMIM]Me2PO4) and 1-ethyl-3- methylimidazolium ethylsulfate ([EMIM]EtSO4) were investigated. 2,2’-azobisiso butyronitrile (AIBN) and dibenzoyl peroxide (BPO) were used as initiators and dimethyl formamide (DMF) and methanol as reference solvents. The influence of the viscosity on the conversion and the molecular weights was studied by variation of the reaction temperature and the IL concentration. At reaction temperatures of 80 - 85 °C already after 30 minutes a conversion of about 80 % and almost a doubling of the molecular weights is reached for the S/AN (50/50 mol%) copolymerization. In addition the copolymerization behavior of S/AN in [EMIM]EtSO4 was investigated. With increasing concentration of AN in the monomer feed the polymerization rate as well as the molecular weights of the copolymers increase. The influence of the ionic liquid on the copolymer composition, glass-transition temperature and rheological behavior was studied.

Network Structure and Properties of Dimethacrylate-Styrene Matrix Materials

2000 ◽  
Vol 34 (18) ◽  
pp. 1512-1528 ◽  
Author(s):  
H. Li ◽  
E. Burts ◽  
K. Bears ◽  
Q. Ji ◽  
J. J. Lesko ◽  
...  
Keyword(s):  
Radical Copolymerization ◽  
Fiber Reinforced Composites ◽  
Network Density ◽  
Low Molecular Weight ◽  
Reinforced Composites ◽  
Vinyl Esters ◽  
Structure And Properties ◽  
Free Radical Copolymerization ◽  
Molecular Weights ◽  
Structural Composite

One of the major classes of polymer matrix resins under consideration for structural composite applications in the infrastructure and construction industries is theso-called "vinyl esters." These are comprised of low molecular weight poly (hydroxyether) oligomers with methacrylate endgroups diluted with styrene monomer. The methacrylate oligomeric endgroups co-cure with the styrene in free radical copolymerization to yield thermoset networks. Selected properties of such resins and resultant networks where the molecular weights of the poly(hydroxyether) oligomers have been varied from 700 to 1200 g/mole and the concentration of styrene has been systematically changed are presented. In general, both the glass transition temperatures and fracture toughness of the fully cured networks increased as the styrene was decreased in each oligomer series with different molecular weights. As expected, the volume contraction upon cure also decreased significantly as styrene was decreased, and thus residual cure stresses may be reduced in fiber reinforced composites. The resistance to crack propagation was significantly improved for networks prepared with the 1200 M n dimethacrylate oligomer relative to those from the 700 g/mole material. Crosslink densities were estimated from measurements of the rubbery moduli at T g + 40°C and relationships between network density, chemical composition and properties are discussed.

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