scholarly journals Study on the Synthesis Technology of High Molecular Weight Hydrophilic Polyether

2021 ◽  
Vol 2101 (1) ◽  
pp. 012080
Author(s):  
Xin Zhao ◽  
Shirui Xu ◽  
Dandan Huang ◽  
Jinwei Ji

Abstract KOH is used as a catalyst. The synthesis of a high molecular weight (relative molecular mass) hydrophilic polyether was carried out. One is to synthesize 1000 molecular weight (relative molecular mass) from the initiator, and then directly synthesize the product (original production process), and then carry out refining treatment by pipetting; the other is to synthesize 1000 molecular weight from the initiator. Molecular mass), further processing in the subsequent synthesis, when the molecular weight reaches 4000 (relative molecular mass), the curing degassing treatment is carried out, and after completion, the mixture of ethylene oxide and propylene oxide is continuously continued to synthesize the product (new production process) ), the synthesis is finished, and after aging, the liquid is pipetted to be refined. The results show that the quality of the new process product is improved, the yield of hydrophilic polyether is improved, and the waterproof effect is improved to 25%; the molecular weight of the old process is not up to the designed molecular weight, and the yield of hydrophilic polyether is lower and the waterproof application effect is less than 25%.

2018 ◽  
Vol 69 (9) ◽  
pp. 873
Author(s):  
Xin Ma ◽  
Xuye Du ◽  
Cunyao Bo ◽  
Hongwei Wang ◽  
Anfei Li ◽  
...  

High-molecular-weight glutenin subunits (HMW-GS) in bread wheat are major determinants of dough viscoelastic properties and the end-use quality of wheat flour. Cysteine residues, which form intermolecular disulphide bonds in HMW-GS, could improve the strength of gluten. To our knowledge, the number and position of cysteine residues in HMW-GS are conserved between wheat (Triticum aestivum) and Aegilops markgrafii. In the present study, we modified a gene (1Cx1.1) from Ae. markgrafii for an HMW-GS that possessed the typical structure and conserved number of cysteines. Site-directed mutagenesis was carried out in 1Cx1.1 to investigate how the position of cysteine residues in HMW-GS affects the mixing properties of dough. Six HMW-GS containing an extra cysteine residue were expressed in Escherichia coli, and the proteins were purified at sufficient scale for incorporation into flour to test dough quality. There were large differences in dough property among samples containing different modified subunits. Cysteine substituting in the N-terminal or repetitive-domain of HMW-GS could significantly improve dough quality. The results showed that the strategy was useful for providing genetic resources for gene engineering, and hence could be valuable for improving the processing quality of wheat.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2489
Author(s):  
Michał Bembenek

When considering the operation of roller presses for the consolidation of fine-grained materials, the main problems are disturbances in the proper flow of the material and its bridging in gravity feeders. This is especially true for small and medium capacity presses, where the hoppers for dosing the material are narrow. This article presents innovative laboratory tests of the impact of using a polymer plate lining in the gravity feeder of a roller press. Polymer materials Polyacetal C (POM C) and Ultra-High-Molecular-Weight Polyethylene (UHMW-PE) were used for the tests. The influence of the use of plates on the material flow and quality of briquettes was investigated in comparison with the case where such plates were not used. The research showed an improvement in the flow of fine-grained materials in the feeder and an increase of the briquette strength indexes, as compared to those cases when polymer linings were not used in the feeder.


2007 ◽  
Vol 79 (11) ◽  
pp. 1887-1894 ◽  
Author(s):  
Alberto de Angelis ◽  
Paolo Pollesel ◽  
Daniele Molinari ◽  
Wallace O'Neal Parker ◽  
Alessandra Frattini ◽  
...  

This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), both molybdenum- and tungsten-based, in the oxidative desulfurization process of diesel. We are jointly developing a new oxidative desulfurization process, aimed at reducing the sulfur content in diesel to less than 10 ppm (parts per million) using in situ produced peroxides. In this new process, high-molecular-weight organosulfur compounds, such as 4,6-dimethyl-dibenzothiophene (DMDBT), difficult to be eliminated by conventional hydrodesulfurization, are oxidized to the corresponding sulfones and subsequently removed by adsorption. Molybdenum-based HPAs, with Keggin structure, proved to be the most active and selective catalysts for oxidizing DMDBT with on-stream lifetimes exceeding 1500 h time on stream (t.o.s.).


2014 ◽  
Vol 1079-1080 ◽  
pp. 33-36
Author(s):  
Le Qun Ma

Polymer, the polymer compound, is composed of millions of atoms with each other, link, for large molecules, so is also known as polymers or polymer. Are you going to give mercerized by large molecular weight, as high as 104 ~ 106, and molecular weight polydispersity. Its relative molecular mass is generally in the tens of thousands to millions. This paper mainly introduces the concept and classification of the polymer materials, and the classification and application of polymer additives. Finally tell the principle and application of polymer materials.


HortScience ◽  
2005 ◽  
Vol 40 (5) ◽  
pp. 1333-1335 ◽  
Author(s):  
Young-Sang Lee ◽  
Yong-Ho Kim ◽  
Sung-Bae Kim

To study the effects of chitosan on the productivity and nutritional quality of soybean (Glycine max L.) sprouts, soybean seeds were soaked in solutions containing 1,000 ppm chitosan of low (<10 kDa), medium (50 to 100 kDa), or high (>1,000 kDa) molecular weight, and the respiration, growth, and vitamin C content of the sprouts were subsequently evaluated. Sprouts treated with high molecular weight chitosan exhibited a significant increase in respiration, 5%, within 1 day of treatment. Chitosan effectively increased the growth of the sprouts: sprouts treated with high molecular weight chitosan showed increases of 3%, 1%, 3%, 1%, and 12% in the total length, hypocotyl length, root length, hypocotyl thickness, and fresh weight, respectively, as compared to a control. The growth-improving effects of chitosan were proportional to the molecular weight of the molecule used in the treatment. Chitosan treatment did not result in any significant reduction in vitamin C content or postharvest chlorophyll formation, traits that determine the nutritional and marketing values of soybean sprouts. All these results suggest that soaking soybean seeds in a solution of chitosan, especially of high molecular weight, may effectively enhance the productivity of soybean sprouts without adverse effects on the nutritional and postharvest characteristics.


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