scholarly journals Proton-transfer Polymerization of Acrylate Monomer Containing Two Carboxyl Groups for Synthesis of Branched Polymer

2017 ◽  
Vol 4 (3) ◽  
pp. 189
Author(s):  
Jun-ichi Kadokawa ◽  
Kyosuke Ikuma ◽  
Hideyuki Tagaya
Keyword(s):  
Proton Transfer ◽  
Analytical Data ◽  
Catalytic Amount ◽  
Carboxyl Groups ◽  
Acrylate Monomer ◽  
Molecular Weights ◽  
Michael Type Addition ◽  
Poly Ethylene ◽  
Proton Transfer Polymerization ◽  
Branched Structure

<p>This paper reports proton-transfer polymerization of an acrylate monomer containing two carboxyl groups. The monomer was synthesized by reaction of DL-malic acid with acrylic anhydride in the presence of a catalytic amount of acryloyl chloride. The polymerization was carried out in the presence of tributylphosphine as an initiator at 100 °C. The product was isolated as a fraction insoluble in a mixture of <em>n</em>-hexane and diethyl ether. The structure of the polymer was determined by the <sup>1</sup>H and <sup>13</sup>C NMR spectra, as well as IR spectrum to be the polyester having a phosphonium end group. The molecular weights were estimated by GPC analyses with water as an eluent using poly(ethylene glycol) standards, which were 5500–11200 with the polydispersities of 1.6–2.6. Based on the analytical data, the following zwitterionic mechanism is proposed. The first step is formation of phosphonium-carboxylate zwitterion species by reaction of the monomer with the initiator. Then, the propagation proceeds via the Michael-type addition between the zwitterion species, followed by the proton-transfer process to give the polymer having ester linkages. Based on the polymerization mechanism, proposed here, the carboxyl groups in the monomer and polymer are considered as the latent propagating species. Therefore, the branched structure of the obtained polymer can be assumed.</p>

Synthesis of hyperbranched polymers via proton-transfer polymerization of acrylate monomer containing two hydroxy groups

2000 ◽  
Vol 21 (7) ◽  
pp. 362-368 ◽  
Author(s):  
Jun-ichi Kadokawa ◽  
Yoshiro Kaneko ◽  
Shigeo Yamada ◽  
Kyosuke Ikuma ◽  
Hideyuki Tagaya ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Hyperbranched Polymers ◽  
Acrylate Monomer ◽  
Proton Transfer Polymerization ◽  
Hydroxy Groups

Influence of the polymer molecular weights on the electrical properties of Poly(vinyl alcohol) – Poly(ethylene glycols)/Graphene oxide nanocomposites

2021 ◽  
Author(s):  
Shurooq S. Al-Abbas ◽  
Rusul A. Ghazi ◽  
Athmar K. Al-shammari ◽  
Nisreen R. Aldulaimi ◽  
Ali R. Abdulridha ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrical Properties ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Molecular Weights ◽  
Ethylene Glycols ◽  
Poly Ethylene

scholarly journals Testing the Performance of Various Polymeric Antiscalants for Mitigation of Sb-Rich Precipitates Mimicking Stibnite-Based Geothermal Deposits

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Celal Çiftçi ◽  
Emre Karaburun ◽  
Serhat Tonkul ◽  
Alper Baba ◽  
Mustafa M. Demir ◽  
...  
Keyword(s):  
Power Plants ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Poly Ethylene Glycol ◽  
Molecular Weights ◽  
Geothermal Fields ◽  
The World ◽  
Testing Potential ◽  
Poly Ethylene ◽  
Poly Vinyl Pyrrolidone

Scaling is frequently observed in geothermal fields and reduces the energy harvesting of power plants. Recently, Sb-rich deposits have developed in many fields around the world. Various polymeric macromolecules have been used as antiscalants to mitigate the formation of scale. Testing potential commercial antiscalants in field conditions is a tedious and costly process. The artificial synthesis of geothermal deposits in the lab is a more practical and economical way to test the performance of antiscalants. This study obtained a Sb-rich deposit by refluxing SbCl3 and Na2S·3H2O in 18 h. The product was found to be a mixture of Sb2O3 and Sb2S3. We examined the performance of antiscalants such as poly(ethylene glycol), poly(vinyl pyrrolidone), Gelatin, and poly(vinyl alcohol) of various molecular weights at 5 to 100 ppm. The formation of Sb2S3 is suppressed in the presence of the polymeric antiscalants. The dosage was found to be critical for the solubilization of Sb-rich deposits. Gelatin of 5 ppm showed the highest performance under the conditions employed in this study. While low dosages improve the concentration of [Sb3+], high dosages are required to increase the solubility of [S2-]. Moreover, the amount of deposit is reduced by 12.4% compared to the reference (in the absence of any polymeric molecules). Thus, comparatively, Gelatin shows the most promising performance among the molecules employed.

scholarly journals Sizing and Thermal Stability of Prepared Tetraaminophthalocyaninatocopper(II) Derivatives-grafted Polymers

2016 ◽  
Vol 13 (2) ◽  
pp. 221-234
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermal Stability ◽  
Ethylene Glycol ◽  
Group Analysis ◽  
Condensation Polymerization ◽  
Grafted Polymers ◽  
Poly Ethylene Glycol ◽  
Molecular Weights ◽  
Poly Ethylene ◽  
Thermal Stability Of ◽  
End Group

Different polymers were prepared by condensation polymerization of sebacic anhydride and adipic anhydride with ethylene glycol and poly(ethylene glycol). Their number average molecular weights were determined by end group analysis. Then, they were grafted on the prepared phthalocyaninatocopper(II) compounds with the general formula (NH2)4PcCu(II) having amino groups of 3,3',3'',3'''- or 4,4',4'',4'''- positions. All prepared polymers, compounds, and phthalocyaninatocopper(II)-grafted polymers were characterized by FTIR. The sizing measurements were carried out in 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) compounds with and without grafting polymers. The results showed that the grafting process led to decreasing in particle size and increasing in surface area. The grafting process was reflected positively on the thermal degradation of 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) grafted polymers. They had higher thermal stability accompanied with higher char residue and T50% weight loss with 3,3',3'',3'''-(NH2)4PcCu(II) and their grafted polymers being the best.

Novel pH-sensitive liposomes: liposomes bearing a poly(ethylene glycol) derivative with carboxyl groups

1994 ◽  
Vol 1193 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Kenji Kono ◽  
Ken-ichi Zenitani ◽  
Toru Takagishi
Keyword(s):  
Ethylene Glycol ◽  
Ph Sensitive ◽  
Carboxyl Groups ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

scholarly journals Poloxamer Hydrogels for Biomedical Applications

Pharmaceutics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 671 ◽  
Author(s):  
Eleonora Russo ◽  
Carla Villa
Keyword(s):  
Drug Delivery ◽  
Ethylene Oxide ◽  
Propylene Oxide ◽  
Biomedical Application ◽  
Aqueous Environment ◽  
Molecular Weights ◽  
Long Time ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Concentration Threshold

This review article focuses on thermoresponsive hydrogels consisting of poloxamers which are of high interest for biomedical application especially in drug delivery for ophthalmic, injectable, transdermal, and vaginal administration. These hydrogels remain fluid at room temperature but become more viscous gel once they are exposed to body temperature. In this way, the gelling system remains at the topical level for a long time and the drug release is controlled and prolonged. Poloxamers are synthetic triblock copolymers of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO), also commercially known as Pluronics®, Synperonics® or Lutrol®. The different poloxamers cover a range of liquids, pastes, and solids, with molecular weights and ethylene oxide–propylene oxide weight ratios varying from 1100 to 14,000 and 1:9 to 8:2, respectively. Concentrated aqueous solutions of poloxamers form thermoreversible gels. In recent years this type of gel has arouse interest for tissue engineering. Finally, the use of poloxamers as biosurfactants is evaluated since they are able to form micelles in an aqueous environment above a concentration threshold known as critical micelle concentration (CMC). This property is exploited for drug delivery and different therapeutic applications.

scholarly journals The binding of hydrogen ions to an acidic glycoprotein from bovine cortical bone

1967 ◽  
Vol 105 (3) ◽  
pp. 1171-1175 ◽  
Author(s):  
A. R. Peacocke ◽  
P A Williams
Keyword(s):  
Sodium Chloride ◽  
Glutamic Acid ◽  
Titration Curve ◽  
Analytical Data ◽  
Total Content ◽  
Bone Sialoprotein ◽  
Model Systems ◽  
Carboxyl Groups ◽  
Hydrogen Ions ◽  
Titration Curves

The H+ ion dissociation of bone sialoprotein in 0·2m-sodium chloride at 25° was studied. The total content of carboxyl groups available for titration was calculated by comparing the titration curve with the titration curves of three model systems and by the use of analytical data. This comparison showed that 7·0 carboxyl groups/mol. do not participate in the titration, and it is proposed that these are aspartic acid or glutamic acid carboxyl groups present as amides; this is also indicated by titration of the sialoprotein after acid hydrolysis. The titration of carboxyl groups was found to agree well with the Linderstrøm-Lang equation for spherical macroions.

scholarly journals Proton-Transfer Polymerization by N-Heterocyclic Carbenes: Monomer and Catalyst Scopes and Mechanism for Converting Dimethacrylates into Unsaturated Polyesters

2016 ◽  
Vol 138 (6) ◽  
pp. 2021-2035 ◽  
Author(s):  
Miao Hong ◽  
Xiaoyan Tang ◽  
Laura Falivene ◽  
Lucia Caporaso ◽  
Luigi Cavallo ◽  
...  
Keyword(s):  
Proton Transfer ◽  
Heterocyclic Carbenes ◽  
Unsaturated Polyesters ◽  
Proton Transfer Polymerization

scholarly journals Synthetic scheme to improve the solid content of biodegradable waterborne polyurethane by changing the association relationships of hydrophilic fragments

RSC Advances ◽  
2020 ◽  
Vol 10 (48) ◽  
pp. 28680-28694 ◽  
Author(s):  
Zhihui Yang ◽  
Guangfeng Wu
Keyword(s):  
Ethylene Glycol ◽  
Waterborne Polyurethane ◽  
Solid Content ◽  
Synthetic Method ◽  
High Solid Content ◽  
Poly Ethylene Glycol ◽  
High Solid ◽  
Molecular Weights ◽  
Waterborne Polyurethanes ◽  
Poly Ethylene

A synthetic method was developed to prepare biodegradable waterborne polyurethanes (BHPUs) with a high solid content by introducing different molecular weights of poly(ethylene glycol) (PEG) into poly(ε-caprolactone) (PCL)-based polyurethanes.

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