condensation polymerization
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2022 ◽  
Vol 2152 (1) ◽  
pp. 012009
Author(s):  
Bo Tian ◽  
Hao Zhang ◽  
Jie Liu ◽  
Yibin Liu ◽  
Chaohe Yang

Abstract With the continuous improvement of big data technology, my country’s coal liquefaction technology has also continued to mature, maintaining a stable industrial development. Traditional coal pyrolysis technology for tar production with the purpose of increasing tar production, such as coal hydropyrolysis, has problems such as high cost of pure hydrogen atmosphere and complex process and equipment operations, which severely restrict its industrial operation process. Based on this, this paper proposes a new technology of coal pyrolysis and depolymerization coupled with oil increase by using hydrogen precipitated by the condensation polymerization reaction at relatively high temperature under big data technology to study the effect of this process on coal pyrolysis for oil production. Experiments show that at 700°C, the tar yield reaches 21.5wt.%, which is 6% and 7% higher than the pyrolysis tar yield under the same conditions under hydrogen and nitrogen atmospheres. At 600°C, the methane aromatization reaction is relatively weak, and it can be seen that the tar yield is only slightly higher than that under hydrogen and nitrogen atmospheres. As the temperature of the methane anaerobic aromatization reaction increases, the equilibrium conversion rate increases accordingly. Therefore, as the reaction temperature increases, the tar yield also begins to increase.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3850
Author(s):  
Yu-Wei Cheng ◽  
Wen-Yao Huang ◽  
Ko-Shan Ho ◽  
Tar-Hwa Hsieh ◽  
Li-Cheng Jheng ◽  
...  

Aromatic polyimine (PIM) was prepared through condensation polymerization between p-phenylene diamine and terephthalaldehyde via Schiff reactions. PIM can be physically crosslinked with ferrous ions into gel. The gel-composites, calcined at two consecutive stages, with temperatures ranging from 600 to 1000 °C, became Fe- and N-doped carbonaceous organic frameworks (FeNC), which demonstrated both graphene- and carbon nanotube-like morphologies and behaved as an electron-conducting medium. After the two-stage calcination, one at 1000 °C in N2 and the other at 900 °C in a mixture of N2 and NH3, an FeNC composite (FeNC-1000A900) was obtained, which demonstrated a significant O2 reduction peak in its current–voltage curve in the O2 atmosphere, and thus, qualified as a catalyst for the oxygen reduction reaction. It also produced a higher reduction current than that of commercial Pt/C in a linear scanning voltage test, and the calculated e-transferred number reached 3.85. The max. power density reached 400 mW·cm−2 for the single cell using FeNC-1000A900 as the cathode catalyst, which was superior to other FeNC catalysts that were calcined at lower temperatures. The FeNC demonstrated only 10% loss of the reduction current at 1600 rpm after 1000 redox cycles, as compared to be 25% loss for the commercial Pt/C catalyst in the durability test.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chaoran Xu ◽  
Congze He ◽  
Ning Li ◽  
Shicheng Yang ◽  
Yuxuan Du ◽  
...  

AbstractThe regulation of polymer topology and the precise control over the monomer sequence is crucial and challenging in polymer science. Herein, we report an efficient solution-phase synthetic strategy to prepare regio- and sequence-controlled conjugated polymers with topological variations via the usage of methyliminodiacetic acid (MIDA) boronates. Based on the solubility of MIDA boronates and their unusual binary affinity for silica gel, the synthesized regio- and sequence-defined conjugated oligomers can be rapidly purified via precipitation or automatic liquid chromatography. These synthesized discrete oligomers can be used for iterative exponential and sequential growth to obtain linear and dendrimer-like star polymers. Moreover, different topological sequence-controlled conjugated polymers are conveniently prepared from these discrete oligomers via condensation polymerization. By investigating the structure-property relationship of these polymers, we find that the optical properties are strongly influenced by the regiochemistry, which may give inspiration to the design of optoelectronic polymeric materials.


2021 ◽  
Vol 880 (1) ◽  
pp. 012032
Author(s):  
M A Munir ◽  
L Y Heng ◽  
K H Badri

Abstract Histamine needs to be determined because of its toxicity. Histamine is commonly determined using chromatography, where not only that the instrument is expensive, the process is very tedious and require an expert. A sensor was developed using palm-based polyurethane as an electro-sensor substrate. Palm-based polyurethane (PU) was produced via condensation polymerization between palm kernel oil-based monoester polyol (PKOp) and 4,4’- diphenylmethane diisocyanate (MDI). PU offers high porosity and capability to attach onto screen–printed electrode (SPE) sturdily without being disintegrated. PU–SPE adsorbed histamine onto its pores, before being oxidized. The oxidation process was detected using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Histamine was oxidized electrochemically at +0.31 V (vs. Ag/AgCl, 1 mol·L-1, pH 7.5). Differential pulse voltemmetric approach were used in order to get a satisfactory response, thus the histamine concentration was made in the range from 1 × 10-4 to 1 mmol·L-1. A good sensitivity of 0.1 mmol·L-1 was attained with 3.07 % during intraday and 9.55 % during interday. The detection and quantification limits of histamine acquired at 0.17 mmol·L-1 and 0.53 mmol·L-1, respectively. A wide variety of interfering compounds were also examined in order to establish their effect, if any, on the determination of histamine at the PU modified electrode. The sensor showed an excellent anti – interference property towards the other amines. The developed chemical sensor using PU – SPE has a good potential to determine histamine level in mackerel (Rastrelliger Brachysoma) owing to its simplicity and reproducibility.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2725
Author(s):  
Mohamed M. Abdelghafour ◽  
Ágoston Orbán ◽  
Ágota Deák ◽  
Łukasz Lamch ◽  
Éva Frank ◽  
...  

Poly(ethylene succinate) (PES) is one of the most promising biodegradable and biocompatible polyesters and is widely used in different biomedical applications. However, little information is available on its solubility and precipitation properties, despite that these solution behavior properties affect its applicability. In order to systematically study these effects, biodegradable and biocompatible poly(ethylene succinate) (PES) was synthesized using ethylene glycol and succinic acid monomers with an equimolar ratio. Despite the optimized reaction temperature (T = 185 °C) of the direct condensation polymerization, relatively low molecular mass values were achieved without using a catalyst, and the Mn was adjustable with the reaction time (40–100 min) in the range of ~850 and ~1300 Da. The obtained crude products were purified by precipitation from THF (“good” solvent) with excess of methanol (“bad” solvent). The solvents for PES oligomers purification were chosen according to the calculated values of solubility parameters by different approaches (Fedors, Hoy and Hoftyzer-van Krevelen). The theta-solvent composition of the PES solution was 0.3 v/v% water and 0.7 v/v% DMSO in this binary mixture. These measurements were also allowed to determine important parameters such as the coefficients A (=0.67) and B (=3.69 × 104) from the Schultz equation, or the Kη (=8.22 × 10−2) and α (=0.52) constants from the Kuhn–Mark–Houwink equation. Hopefully, the prepared PES with different molecular weights is a promising candidate for biomedical applications and the reported data and constants are useful for other researchers who work with this promising polyester.


2021 ◽  
Vol 5 (1) ◽  
pp. 51
Author(s):  
Yanuar Bekti Ramadhan ◽  
Aida Nur Sabrina ◽  
Endang Kwartiningsih

<p>The heavy metal content is very dangerous because it can pollute the environment. One of the heavy metals waste commonly found in the textile industry is chromium (Cr). <em>Mimosa pudica</em> is a weed plant and its availability is very abundant. However, it also contains tannin which can be developed into tannin gel biosorbent to adsorption heavy metal content in the wastewater. The purpose of this research is to study <em>Mimosa pudica</em> tannin as a Cr biosorbent from textile wastewater. There are two steps to synthesis tannin gel biosorbent. They are the tannin extraction and the condensation polymerization process. Tannin is easily soluble in water so the condensation polymerization process is needed to make it insoluble in water. The extraction of <em>Mimosa pudica </em>tannin was done using water solvent. The condensation polymerization process was done by the reaction of tannin extract and formaldehyde. The Cr content of textile industry wastewater in the Pasar Kliwon, Surakarta was 4 ppm. The results of the biosorption of Cr heavy metal using <em>Mimosa pudica</em> tannin gel showed that the remaining Cr heavy metal was 0.7098 ppm. It was already below the threshold which was 1 ppm.</p><p> </p><p><strong>Keywords:</strong> biosorption, condensation polymerization, extraction, <em>Mimosa pudica</em>, tannin gel</p>


2021 ◽  
Author(s):  
Muktikanta Panigrahi ◽  
Saralasrita Mohanty ◽  
Ratan Indu Ganguly ◽  
Radha Raman Dash

In the present Investigation, Geopolymer (GP) is made using High carbon Ferrochrome (HCFC) slag by synthesizing silicon and aluminum present in it with alkali liquid solution which binds other non-reactive materials present in the slag. The compressive strength of GP is found to be 11 MPa after 7-days of air curing. Increasing air curing time to 28-days, the strength is measured to be 15 MPa. XRD analyses indicate that there is gradual transformation of crystalline phases to non-crystalline glassy phases. SEM images show presence of more amount of glassy phase after air curing for a longer time. This is also corroborated with mechanical properties such as compressive strength. TGA results are also discussed for both uncured and cured GP samples. DSC isotherms indicate oozing out of inbuilt water present in the prepared GP materials which is an indication of condensation polymerization reaction occurring during the formation of Geopolymers.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1743
Author(s):  
Marianito Tiangson Margarito ◽  
Arnel Bas Beltran ◽  
Aileen Huelgas-Orbecido

This study aims to integrate copper (Cu) during membrane formation by a facile simultaneous phase separation process to alleviate biofouling and improve membrane performance. Polythiourea (PTU) polymer synthesized through condensation polymerization of 4,4-oxydianiline and p-phenylene diisothiocyanate in dimethyl sulfoxide was used in the preparation of dope solution. By incorporating different concentrations of cupric acetate in the non-solvent bath, both non-solvent induced phase separation and complexation induced phase separation occur instantaneously. Scanning electron microscopy—energy dispersive X-ray, fourier-transform infrared spectroscopy and time-of-flight secondary ion mass spectroscopy analysis accompanied by color change of the membrane surfaces—confirms the interaction of the polymer with Cu. Interaction of Cu at the interface during membrane formation results in a decrease in contact angle from 2 to 10° and a decrease in surface roughness from 30% to 52% as measured by atomic force microscope analysis. Pure water flux of PTU-Cu membrane increased by a factor of 3 to 17 relative to pristine PTU membrane. Both the pristine PTU and PTU-Cu membrane showed antibacterial characteristics against E. coli.


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