Preparation of new copolymer (polystyrene/TMSPM grafted on DDA-fractionated algerian montmorillonite) hybrid organoclay by radical copolymerization: structural study, thermal stability and hydrophobicity area

2021 ◽  
Author(s):  
Azzedine Melouki ◽  
Smail Terchi ◽  
Dehimi Ouali ◽  
Abdelhakim Bounab
Keyword(s):  
Thermal Stability ◽  
Structural Study ◽  
Radical Copolymerization

Preparation and characterization of a novel amphoteric polymer for oil well cementing with superior performances

2020 ◽  
Vol 29 (1) ◽  
pp. 29-39
Author(s):  
Tang Xin ◽  
Hu Xuzeng ◽  
Wan Haodong
Keyword(s):  
Thermal Stability ◽  
Orthogonal Experiment ◽  
Radical Copolymerization ◽  
Proton Nuclear Magnetic Resonance ◽  
Fluid Loss ◽  
Resonance Spectroscopy ◽  
Oil Well ◽  
Cement Slurry ◽  
Synthesis Conditions ◽  
Th 1

A novel amphoteric polymer TH-1 was synthesized using the monomers of 2-acrylamido-2-methylpropane sulfonic acid, acrylic acid, acrylamide, and cationic monomer through radical copolymerization as filtrate loss reducer in oil well cementing. Optimal synthesis conditions of TH-1 were obtained by an orthogonal experiment. The composition of copolymer (TH-1) was characterized by Fourier-transform infrared spectrum and proton nuclear magnetic resonance spectroscopy. The thermal stability of the synthesized copolymer was tested by thermogravimetric analysis. The fluid loss (FL) control and thickening performance of cement slurry incorporating TH-1 were evaluated at different temperatures. The filtration reduction mechanism of TH-1 was finally discussed. Results suggest that the amphoteric polymer is the target product polymerized by all the monomers, which presents excellent filtrate reduction property, high thermal stability, and strong saline tolerance under 200°C. The amphoteric polymer TH-1 includes cationic and anionic group in a molecule structure, which can adsorb firmly onto the surface of cement particles through electrostatic attraction and form adsorption membrane of viscoelastic polymer. In this way, compact cement filter cakes are formed, thereby efficiently reducing the FL.

scholarly journals A TEM structural study of thermal stability of magnetic tunnel junctions integrated with CMOS devices

2008 ◽  
Vol 126 ◽  
pp. 012002 ◽  
Author(s):  
V K Lazarov ◽  
A Kohn ◽  
T Uhrmann ◽  
T Dimopoulos ◽  
H Brückl ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Structural Study ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Thermal Stability Of

Synthesis and structural study from X-ray powder diffraction of Pb0.5Th2(PO4)3

1997 ◽  
Vol 12 (2) ◽  
pp. 76-80 ◽  
Author(s):  
A. El-Yacoubi ◽  
R. Brochu ◽  
A. Serghini ◽  
M. Louër ◽  
M. Alami Talbi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Structural Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Thermal Stability Of

A new mixed lead thorium phosphate, Pb0.5Th2(PO4)3, has been isolated in the system PbO–ThO2–P2O5. Its crystal structure (monoclinic symmetry, a=17.459(1) Å, b=6.8451(4) Å, c=8.1438(5) Å, β=101.247(5)°, space group C2/c) has been determined from conventional monochromatic X-ray powder diffraction data. The structure is related to the MITh2(PO4)3 structure type. Lead atoms are located in the channels parallel to the c axis, out of the twofold axis for 0.97 Å, and are statistically distributed on a quarter of crystallographic positions. The thermal stability of this material is greater than that of the monazite-type compound PbTh(PO4)2.

Synthesis and investigation of a novel luminous hydrogel

2016 ◽  
Vol 7 (22) ◽  
pp. 3766-3772 ◽  
Author(s):  
Dongfeng Fan ◽  
Xu Fei ◽  
Jing Tian ◽  
Hui Zhi ◽  
Longquan Xu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Free Radical ◽  
Radical Copolymerization ◽  
Ester Hydrolysis ◽  
Free Radical Copolymerization ◽  
Excellent Thermal Stability ◽  
Red Fluorescence

An Eu-containing luminous hydrogel was synthesized by free radical copolymerization and ester hydrolysis. The hydrogel exhibits strong red fluorescence, excellent thermal stability and superhydrophilicity.

scholarly journals Synthesis, Characterization and Copolymerization of N-(phenylamino)maleimide with MMA

2007 ◽  
Vol 4 (2) ◽  
pp. 265-271
Author(s):  
B. L. Hiran ◽  
S. N. Paliwal ◽  
Jyoti Choudhary ◽  
P. R. Choudhary
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Density Measurement ◽  
Gel Permeation Chromatography ◽  
Radical Copolymerization ◽  
Free Radical Copolymerization ◽  
H Nmr ◽  
Gel Permeation ◽  
Ft Ir ◽  
Thermal Stability Of

The free radical copolymerization of N-(phenylamino)maleimide (N-PAMI) was carried. The copolymerization with methyl methacrylate (MMA) was performed at 65°C with AIBN as the initiator in THF solvent. Resulting copolymer was characterized by density measurement, intrinsic viscosity, solubility, FT-IR &1H NMR spectroscopy. Effect of the solvent and time on copolymer yield was also investigated. The molecular weight of copolymer was determined by gel permeation chromatography (GPC). The thermal stability of copolymer was determined by Thermogravimetric analysis (TGA).

Self-Degradable Hydrogel with Covalently Bound Proteolytic Enzyme

1995 ◽  
Vol 60 (11) ◽  
pp. 1986-1994 ◽  
Author(s):  
František Rypáček ◽  
Václav Škarda
Keyword(s):  
Thermal Stability ◽  
Proteolytic Enzyme ◽  
Radical Copolymerization ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Ph Optimum ◽  
Biodegradable Poly ◽  
Biodegradable Hydrogel ◽  
Enzyme Conjugate ◽  
Covalently Bound

Biodegradable hydrogel as a self-degradable system for controlled release of biologically active macromolecules was prepared from the biodegradable poly[N5-(2-hydroxyethyl)-L-glutamine-stat -N5-(2-methacryloyloxyethyl)-L-glutamine -stat-L-glutamic acid], to which a proteolytic enzyme, papain, was covalently bound. The polymer-enzyme conjugate was crosslinked by radical copolymerization with acrylamide. Significantly improved thermal stability and increased pH optimum of the catalytic activity of conjugated papain was observed. Self-degradation of the hydrogel by the action of encapsulated papain could be triggered by the addition of a low-molecular-weight enzyme activator, such as dithioerythritol.

scholarly journals Stereocomplex Poly(Lactic Acid) Amphiphilic Conetwork Gel with Temperature and pH Dual Sensitivity

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1940 ◽  
Author(s):  
Jie Wu ◽  
Xiaoyu Shi ◽  
Zhidan Wang ◽  
Fei Song ◽  
Wenli Gao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Radical Copolymerization ◽  
Ph Sensitivity ◽  
Proton Nuclear Magnetic Resonance ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Free Radical Copolymerization ◽  
Good Thermal Stability ◽  
Ft Ir

A novel stereocomplex poly(lactic acid) amphiphilic conetwork gel with temperature and pH dual sensitivity was synthesized by ring-opening polymerization (ROP) and free radical copolymerization. The chemical structure and composition of hydrogel were characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H NMR) and X-ray diffraction (XRD). The temperature and pH sensitivity and good amphiphilicity of hydrogel were studied using digital photos, the swelling ratios and a scanning electron microscope (SEM). The thermal stability and mechanical properties of hydrogel were studied by differential scanning calorimeter (DSC) and dynamic viscoelastic spectrometer. The results indicated that the hydrogel has amphiphilicity, temperature and pH sensitivity, good thermal stability and mechanical strength.

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