Low-Molecular-Weight Copolymer for Calcium Scale Inhibition at High Temperature

2009 ◽  
Author(s):  
Bisweswar Ghosh ◽  
B. Senthilmurugan
Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 406 ◽  
Author(s):  
Yuwei Zuo ◽  
Wenzhong Yang ◽  
Kegui Zhang ◽  
Yun Chen ◽  
Xiaoshuang Yin ◽  
...  

Poly acrylic acid (PAA) and polyepoxysuccinic acid (PESA) were investigated as scale inhibitors. The static experiments certified that PAA was superior to PESA for the inhibition of calcium carbonate in the low molecular weight range. The X-ray diffraction patterns suggest that the effect of PAA on the calcite (1 0 4) and (1 1 0) crystal plane was more obvious. Scanning electron microscopy was used to study the surface morphology of the depositions, which indicated that the addition of scale inhibitors could disturb the normal growth of CaCO3 scale. The transmittance ratio of ferric oxide demonstrated that PAA had a better dispersion performance than PESA. The molecular dynamics simulation and quantum calculation were selected to theoretically explore the mechanism and structure of scale inhibitors, indicating that the interaction of PAA with (1 0 4) and (1 1 0) calcite crystal surfaces was stronger than PESA. In addition, the results indicated that the PAA with negative charge more easily adsorbed free Ca2+ in the aqueous phase. Based on these observations, PAA exhibited better scale inhibition and dispersion effects than PESA in the case of low molecular weight.


Author(s):  
R.R. Baker ◽  
K.D. Kilburn

AbstractMeasurements have been made of the distribution of temperature and low molecular weight gases within a burning cigarette, using a sampling probe coupled directly to a mass spectrometer (or Bosch carbon monoxide meter). The interior of the combustion coal is effectively an oxygen-deficient pyrolytic region. The oxides of carbon are produced in two distinct regions: a high-temperature (about 400-800°C) combustion region and a low- temperature (about 150-400°C) pyrolysis region. In the high-temperature coal the carbonised tobacco acts very much as a classical oxidizing solid fuel bed of carbon to give the two carbon oxides (and water). In the low-temperature region behind the coaI tobacco decomposes to give a substantiaI proportion of the carbon oxides and a major proportion of the hydrocarbons found in mainstream smoke.


2020 ◽  
Author(s):  
Lyaysan Amirova ◽  
Fabian Schadt ◽  
Markus Grob ◽  
Christian Brauner ◽  
Thomas Ricard ◽  
...  

AbstractA high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach. The phase separation, curing behavior and thermal properties were studied using hot stage microscopy, differential scanning calorimetry and dynamic mechanical analysis. Results showed the difference in the morphology for blends with different molecular weight PES explained by possible network formation. The influence of PES content on the glass transition temperature and mechanical properties was investigated. The most significant toughening effect (increase of 132% in fracture toughness) was achieved on a functionalized low molecular weight PES (20 parts per hundred of resin, phr). Rheology investigation allowed to estimate the optimal content of PES (15 phr) for further prepreg manufacturing.


2020 ◽  
Vol 200 ◽  
pp. 210-220
Author(s):  
O. Ya. Mezenova ◽  
L. S. Baydalinova ◽  
N. Yu. Mezenova ◽  
S. V. Agafonova ◽  
E. A. Kazimirova ◽  
...  

Processing of secondary raw materials from production of canned food «Sprats in oil» is considered. Comprehensive technology is developed for producing of protein, fat, and protein-mineral food additives from the sprat waste, as smoked sprat heads, using the method of high temperature hydrolysis. Rational method of the hydrolysis is substantiated, including preliminary separation of fat in fatty raw materials and its enzymatic-thermal treatment. The optimal values of temperature and duration of hydrolysis in autoclave are determined. Balances of organic substances are calculated for the main operations. This new technology was tested for fatty (24 %) and medium fat (13 %) raw materials under the temperature of 130–160 о С. The hydrolyzed organic mass was divided into fat, protein, and mineralized fractions and proteinfat emulsion. Food additives containing low molecular weight water-soluble peptides and high molecular weight insoluble proteins were extracted from the protein fraction by freeze-drying and mineral compounds were extracted from the mineral fraction by convective drying. The proteins were extracted more thoroughly, so the content of low molecular weight peptides in the freeze-dried hydrolysate of protein fraction was > 80 %. The produced additives have pleasant organoleptic properties and are sanitary safe. They are tested with some seafood, with positive result. The developed technology for processing of smoked waste is economically valuable and allows to solve the problem of pollution in the fish smoking industry.


2019 ◽  
Vol 48 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Nesrin Köken

Purpose The purpose of this paper is to prepare poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid]s by two different routes. In the first route, poly(allyl amine-ran-acrylic acid)s were produced by radical copolymerization of a mixture of ally amine and acrylic acid, then converted into poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid]s by the Mannich reaction with a mixture of formaldehyde and phosphonic acid. In the second route, allyl amino bis(methylene phosphonic acid) monomer was synthesized and copolymerised with acrylic acid. The aim of this work is to produce low-molecular-weight copolymer with the low amount of nitrogen and phosphorous having better scale inhibiting performance than commercial low-molecular-weight poly(acrylic acid)s. Design/methodology/approach Poly(allyl amine-ran-acrylic acid)s were prepared by radical copolymerisation of a mixture of ally amine and acrylic acid, and the molecular weight of copolymers was regulated by using an effective chain transfer compound and the formed copolymer was reacted with a mixture of formaldehyde and phosphorous acid. Allyl amino bis(methylene phosphonic acid) monomer was prepared and then copolymerised with acrylic acid using radical initiators. Findings Poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] produced with both routes, especially low-molecular weight ones have better anti-scaling performance than low-molecular-weight commercial poly(acrylic acid). Research limitations/implications By using an excess of formaldehyde and phosphonic acid, a limited increase in the conversion of amine groups of poly(allyl amine-ran-acrylic acid) to amino methylene phosphonic acid groups was achieved, so unreacted amine groups were always present in the structure of the final copolymers. Practical implications The low-molecular-weight poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] may be used as a better anti-scaling polymer in industry. Social implications The low-molecular-weight poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] is an alternative polymer for scale inhibition in the water boilers. Originality/value The low-molecular-weight poly[allyl amino bis(methylene phosphonic acid)-ran-acrylic acid] copolymers containing both carboxylic acid and amino bis(methylene phosphonic acid) are more effective anti-scaling additives than poly(acrylic acid)s in water boilers.


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