DOCSLIB.ORG

Process for the Manufacture of Polyaspartic Acid Verfahren Zur Herstellung Von Polyasparaginsäure Procédé De Préparation D’Acide Polyaspartique

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Process for the Manufacture of Polyaspartic Acid Verfahren Zur Herstellung Von Polyasparaginsäure Procédé De Préparation D’Acide Polyaspartique Europäisches Patentamt & (19) European Patent Office Office européen des brevets (11) EP 1 083 194 B9 (12) CORRECTED EUROPEAN PATENT SPECIFICATION Note: Bibliography reflects the latest situation (15) Correction information: (51) Int Cl.: Corrected version no 1 (W1 B1) C08G 73/10 (2006.01) C08G 73/06 (2006.01) Corrections, see page(s) 3 (48) Corrigendum issued on: 20.12.2006 Bulletin 2006/51 (45) Date of publication and mention of the grant of the patent: 10.05.2006 Bulletin 2006/19 (21) Application number: 00307798.9 (22) Date of filing: 08.09.2000 (54) Process for the manufacture of polyaspartic acid Verfahren zur Herstellung von Polyasparaginsäure Procédé de préparation d’acide polyaspartique (84) Designated Contracting States: • Yasuda, Shinzo AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU Ushiku-shi, MC NL PT SE Ibaraki 300-1236 (JP) (30) Priority: 10.09.1999 JP 25797399 (74) Representative: Bassil, Nicholas Charles et al Kilburn & Strode (43) Date of publication of application: 20 Red Lion Street 14.03.2001 Bulletin 2001/11 London WC1R 4PJ (GB) (73) Proprietor: NIPPON SHOKUBAI CO., LTD. (56) References cited: Osaka-shi, Osaka 541-0043 (JP) US-A- 5 688 902 US-A- 5 830 985 US-A- 5 888 959 US-A- 5 929 198 (72) Inventors: • Mukouyama, Masaharu Tsukuba-gun, Ibaraki 300-1236 (JP) Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 1 083 194 B9 Printed by Jouve, 75001 PARIS (FR) EP 1 083 194 B9 Description [0001] This invention relates to a polyaspartic acid excelling in biodegradability and a method for the production thereof. [0002] Conventionally polyaspartic acid has been produced by the dehydrating method which comprises heating solid 5 aspartic acid thereby removing water therefrom. Methods which comprise heating solid aspartic acid in the presence of an acid catalyst (US 5688902, US 5457176, and US 5830985) or in the absence of a catalyst (US 5391764 and US 5319145) by using a varying drying machine, a kneading and heating device, or an oven in the neighborhood of 200°C thereby dehydrating and condensing the solid aspartic acid, heating solid aspartic acid in an organic solvent of a high boiling point thereby removing the water of condensation by azeotropy (US 5380817, US 5484945, and US 5756595), 10 have been heretofore proposed for the production of polyaspartic acid. [0003] For the purpose of polymerizing aspartic acid by using sulfuric acid, phosphoric acid, or boric acid as an acid catalyst, methods which comprises continuing the polymerization while removing the water of polymerization, and using water for aiding in uniformly mixing the acid catalyst with the aspartic acid have been disclosed. These methods, however, produce a substantially dried solid polymer by removing the water of polymerization by decompression, exposure to a 15 stream of nitrogen, or azeotropy notwithstanding the relevant reactions proceed in their initial stages in the presence of water. [0004] In these methods the solid aspartic acid tends to form a bulk substance during the course of polymerization and, therefore, it needs to perform such actions as disintegration on the bulk substance during the course of polymeri- zation. Particularly when the acid catalyst is used, the polymerization forms a bulk substance like candy, thus this bulk 20 substance must be disintegrated. [0005] Further, the material derived from aspartic acid by heating in these methods is a solid polysuccinimide which is an intermediate of polyaspartic acid. The polysuccinimide is hydrolyzed with a base to produce a polyaspartic acid salt. [0006] It is an object of this invention to obtain directly an acid type polyaspartic acid by a method which avoids forming a bulk substance in producing the polyaspartic acid by condensing an amino acid having aspartic acid essentially. 25 [0007] It is further an object of this invention to provide a polyaspartic acid with improved biodegradability. [0008] The conventional method consists in performing the relevant polymerization while removing the water of po- lymerization. Unexpectedly it has been found that when an amino acid having aspartic acid as an essential component is suspended in water and heated, polyaspartic acid is formed even in the presence of water, the polymer yield exceeds 80%, the formed polymer is obtained in a state dissolved in water, and the polymer is an acid type polyaspartic acid 30 polymer. As a result, this invention has been achieved. [0009] The object of this invention is accomplished by a method for the production of a polyaspartic acid characterized by the steps of mixing an amino acid having aspartic acid as an essential component with water and heating the resultant mixture in a vessel having an inner pressure exceeding 0,3 mPa. [0010] Further, the object of this invention is accomplished by a polyaspartic acid having such biodegradability that 35 the ratio of biodegradation per 7 days of BOD is not less than 45%. [0011] By the method of production according to this invention, a polyaspartic acid (containing an amino acid having polyaspartic acid as an essential component) having an excellent biodegradability can be obtained by an extremely simple procedure. [0012] The polyaspartic acid of this invention is excellent particularly in biodegradability. 40 [0013] Since the polyaspartic acid of this invention excels in biodegradability, it is suitable as detergent additives, dispersion stabilizers, scale preventing agents, humectants, and fertilizers. [0014] The above and other objects, features and advantages of the present invention will become clear from the following description of the preferred embodiments. [0015] The term "polyaspartic acid" as used herein also embraces salts of polyaspartic acid. The counterions of 45 polyaspartic acid include, but not limited to those below, for example alkali metals and alkaline earth metals, specifically sodium, potassium, magnesium, calcium, strontium, and ammonium cations. [0016] This invention uses, as the raw material, an amino acid having aspartic acid as an essential component. The aspartic acid can be used in the form of L-, D-, or a mixture thereof. The aspartic acid may additionally incorporate therein one or more other amino acids in an amount up to 99 % by weight, preferably 5 to 99% by weight, based on the weight 50 of the aspartic acid. Suitable examples of the other amino acids may include glycin, alanine, asparagine, glutamic acid, lysine, valine, leucine, isoleucine, phenylalanine, methionine, histidine, proline, serine, threonine, and cysteine. Among other amino acids mentioned above, L-glutamic acid, L- alanine, and L-lysine prove particularly preferable because they are inexpensive and the polymers produced have high water solubility. [0017] In this invention, polyaspartic acid can be produced by heating an amino acid having aspartic acid as an 55 essential component (hereinafter occasionally referred to simply as "aspartic acid") in the presence of water. [0018] The amount of the water to be used in the polymerization, though not particularly limited, generally has a lower limit of not less than 0.2 times, preferably not less than 0.5 times, and more preferably not less than 1 times and an upper limit of not more than 40 times, preferably not more than 20 times, and more preferably not more than 10 times 2 EP 1 083 194 B9 the weight of the amino acid having aspartic acid as a main component. The amount of the water is preferred to be in the range of 0.2 to 40 times, especially 0.5 to 20 times, based on the weight of the amino acid having aspartic acid as the main component. If the amount is less than 0.2 times, the shortage will be at a disadvantage in suffering the resultant polymer to assume a bulk form. If this amount exceeds 40 times, the excess will be at a disadvantage in suffering the 5 aqueous solution of the produced polymer to have an unduly low concentration and rendering the polymerization une- conomical. [0019] The heating temperature in the polymerization, though not particularly limited, generally has a lower limit of not less than 140°C, preferably not less than 150°C, and more preferably not less than 160°C and an upper limit of not more than 300°C, preferably not more than 250°C, and more preferably not more than 220°C. The heating temperature is 10 preferred to be in the range of 140 to 300 °C, especially 150 to 250 °C. If the heating temperature is less than 100°C, the shortage will be at a disadvantage in lowering the yield of polymer. Conversely, if it exceeds 300°C, the excess will be at a disadvantage in impairing the biodegradability, one of the characteristics of the produced polymer. [0020] The reaction is generally performed in a closed vessel proof against pressure, therefore, preferred to have an inner pressure exceeding 0.3 MPa, preferably in the range of 0.5 - 4 MPa. 15 [0021] An acid catalyst is preferably added in the polymerization of an amino acid. Commendably, an organic or inorganic acid having a lower pKa value than that of aspartic acid is used as the acid catalyst. Suitable examples of the inorganic acid may include phosphoric acids such as orthophosphoric, metaphosphoric, and polyphosphoric acids, phosphonic acids, phosphinic acids, sulfuric acid, sulfurous acid, pyrosulfuric acid, boric acid, and trifluoromethane sulfonic acid. Suitable examples of the organic acid may include acidic phosphoric esters such as methyl phosphoric, 20 ethyl phosphoric, and phenyl phosphoric acids, phosphonic esters such as methyl phosphonic, ethyl phosphonic, butyl phosphonic, lauryl phosphonic, stearyl phosphonic, and phenyl phosphonic acids, and methane sulfonic acid and para- toluene sulfonic acid.
Load more
Loading...
Loading...
Loading...
Loading...
Loading...

7 pages remaining, click to load more.

Recommended publications
  • Stimuli-Responsive Poly(Aspartamide) Derivatives and Their Applications As Drug Carriers
    International Journal of Molecular Sciences Review Stimuli-Responsive Poly(aspartamide) Derivatives and Their Applications as Drug Carriers Guangyan Zhang 1,2,* , Hui Yi 1 and Chenhui Bao 1 1 School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan 430068, China; yihuihbut@163.com (H.Y.); xiaochengzikid@163.com (C.B.) 2 Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan 430068, China * Correspondence: zhangguangyan@whu.edu.cn Abstract: Poly(aspartamide) derivatives, one kind of amino acid-based polymers with excellent biocompatibility and biodegradability, meet the key requirements for application in various areas of biomedicine. Poly(aspartamide) derivatives with stimuli-responsiveness can usually respond to external stimuli to change their chemical or physical properties. Using external stimuli such as tem- perature and pH as switches, these smart poly(aspartamide) derivatives can be used for convenient drug loading and controlled release. Here, we review the synthesis strategies for preparing these stimuli-responsive poly(aspartamide) derivatives and the latest developments in their applications as drug carriers. Keywords: poly(aspartamide) derivatives; stimuli-responsive; drug carrier; nanoparticles; hydrogel; polymer-drug conjugate; drug-loading; controlled drug release Citation: Zhang, G.; Yi, H.; Bao, C. Stimuli-Responsive Poly(aspartamide) Derivatives and 1. Introduction Their Applications as Drug Carriers. Though the carbon-carbon backbone is conducive to the stability of polymers, it also Int. J. Mol. Sci. 2021, 22, 8817. limits the applications of these polymers in biomedical fields due to its low biocompat- http://doi.org/10.3390/ijms22168817 ibility and non-biodegradability. In the past decades, the interest in amino acid-based biodegradable polymers has increased significantly in biomedicine due to their good Academic Editors: Ádám Juhász and biocompatibility, biodegradability and non-toxicity of their degradation products.
    [Show full text]
  • Cross-Linked Polymer
    s\ — Illl INI II III II I II 1 1 IN II II I II OJII Eur°Pean Patent Office <*S Office europeen des brevets (11) EP 0 856 539 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) |nt. CI.6: C08G 73/02 05.08.1998 Bulletin 1998/32 (21) Application number: 98101400.4 (22) Date of filing: 27.01.1998 (84) Designated Contracting States: (72) Inventors: AT BE CH DE DK ES Fl FR GB GR IE IT LI LU MC • Irizato, Yoshihiro NL PT SE Yokohama-shi, Kanagawa (JP) Designated Extension States: • Sukegawa, Makoto AL LT LV MK RO SI Yokohama-shi, Kanagawa (JP) • Katoh, Toshio (30) Priority: 30.01.1997 JP 16991/97 Kawaguchi-shi, Saitama (JP) 24.04.1 997 JP 1 07772/97 . Tamatani, Hiroaki 24.04.1 997 JP 1 07773/97 Yokohama-shi, Kanagawa (JP) (71) Applicant: (74) Representative: MITSUI CHEMICALS, INC. Strehl Schubel-Hopf & Partner Tokyo (JP) Maximilianstrasse 54 80538 Munchen (DE) (54) Cross-linked polymer (57) A cross-linked polymer containing, in its molecule, recurring units represented by the following formula (1), and having biodegradability and high water-absorbency: wherein R-| is a pendant group having at least one functional group selected from the group consisting of acidic groups and salts thereof, a glycino group and salts thereof, cationic groups and betaine groups; X-| is NH, NRi', R^ being an alkyl, aralkyl or aryl group, O or S; and n-\ is 1 or 2. < CO LO CO LO CO o Q_ LU Printed by Xerox (UK) Business Services 2.16.3/3.4 EP 0 856 539 A1 Description BACKGROUND OF THE INVENTION 5 1 .
    [Show full text]
  • Preparation of Injectable Hydrogel with Near-Infrared Light Response And
    Zhao et al. Bioresour. Bioprocess. (2020) 7:1 https://doi.org/10.1186/s40643-019-0289-x RESEARCH Open Access Preparation of injectable hydrogel with near-infrared light response and photo-controlled drug release Jianbo Zhao1,2, Xingxing Liang1, Hui Cao1* and Tianwei Tan1 Abstract Photo-controlled release hydrogel provides a new strategy for treating tumours. Under the stimulation of external light sources, the ability to release the entrapped drug on time and space on demand has outstanding advantages in improving drug utilisation, optimising treatment, and reducing toxicity and side efects. In this study, a photo- controlled drug delivery system for disulphide cross-linked polyaspartic acid (PASP-SS) hydrogels encapsulating proteinase K (ProK) adsorbed with platinum nanoparticles (PtNPs) was designed. The injectable cysteamine-modifed polyaspartic acid (PASP-SH) sol and PtNPs adsorbed by ProK (ProK-PtNPs) as regulatory factors were prepared. Then, ProK-PtNPs and lentinan were dissolved in the sol, and the oxidant was added to the matrix to form the gel in situ quickly after injection. Finally, the degradation of PASP-SS hydrogel by ProK and the controllability of drug release under near-infrared (NIR) light irradiation were elucidated. In vitro degradation of hydrogels and drug release experi- ments showed that the degradation rate of PASP-SS hydrogel signifcantly increased and the drug release rate increased signifcantly under near-infrared radiation. The results of cytotoxicity test showed that PASP-SS, ProK-PtNPs, and lentinan all had more than 90% cell survival rate on NIH3T3, and the lentinan released from the carrier obviously inhibited the proliferation of MCF7. PASP hydrogel has the potential to respond to on-demand light control.
    [Show full text]
  • Presidential Green Chemistry Challenge: Award Recipients, 1996
    The Presidential Green Chemistry Challenge Award Recipients 1996—2014 Contents Introduction................................................................................................................1 2014 Winners Academic Award: Professor Shannon S. Stahl, University of Wisconsin-Madison .......................................................................2 Small Business Award: Amyris..................................................................................................................... 3 Greener Synthetic Pathways Award: Solazyme, Inc. ....................................................................................................... 4 Greener Reaction Conditions Award: QD Vision, Inc. ..................................................................................................... 5 Designing Greener Chemicals Award: The Solberg Company...........................................................................................6 2013 Winners Academic Award: Professor Richard P. Wool, University of Delaware ........................................................................................7 Small Business Award: Faraday Technology, Inc........................................................................................ 8 Greener Synthetic Pathways Award: Life Technologies Corporation ............................................................................. 9 Greener Reaction Conditions Award: The Dow Chemical Company...............................................................................10
    [Show full text]
  • Polyaspartic Acid and Its Salts for Dispersing
    Europaisches Patentamt (19) European Patent Office Office europeenpeen des brevets EP 0 688 347 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) intci.6: C08L 77/04, C08K5/17, of the grant of the patent: B01F 17/28, C08G 69/10, 24.11.1999 Bulletin 1999/47 C08G 73/06, B01F 17/00, C02F5/12 (21) Application number: 94909749.7 C11D3/37, (22) Date of filing: 15.02.1994 (86) International application number: PCT/US94/01886 (87) International publication number: WO 94/19409 (01.09.1994 Gazette 1994/20) (54) POLYASPARTIC ACID AND ITS SALTS FOR DISPERSING SUSPENDED SOLIDS VERWENDUNG VON POLYASPARAGINSAURE UND DEREN SALZEN ZUR DISPERSION VON SUSPENDIERTEN FESTSTOFFEN ACIDE POLYASPARTIQUE ET SES SELS UTILISES POUR DISPERSER DES SOLIDES EN SUSPENSION (84) Designated Contracting States: • LOW, Kim C. DE FR GB IT NL La Grange, Illinois 60525 (US) (30) Priority: 16.02.1993 US 18008 (74) Representative: Eddowes, Simon et al Hepworth Lawrence Bryer & Bizley, (43) Date of publication of application: Merlin House, 27.12.1995 Bulletin 1995/52 Falconry Court, Bakers Lane (73) Proprietor: DONLAR CORPORATION Epping, Essex CM16 5DQ (GB) Bedford Park, IL 60501 (US) (56) References cited: (72) Inventors: EP-A- 0 686 657 WO-A-92/16463 • KOSKAN, Larry, P. US-A- 3 846 380 US-A- 4 640 943 Orland Park, IL 60462 (US) DO Is- ^- CO 00 00 CO Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice the Patent Office of the Notice of shall be filed in o to European opposition to European patent granted.
    [Show full text]
  • Superabsorbent Polymer Network Degradable by a Human Urinary Enzyme
    polymers Article Superabsorbent Polymer Network Degradable by a Human Urinary Enzyme Minji Whang †, Hyeonji Yu † and Jungwook Kim * Department of Chemical and Biomolecular Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Korea; mjwhang@sogang.ac.kr (M.W.); lkjh6309@sogang.ac.kr (H.Y.) * Correspondence: jungwkim@sogang.ac.kr; Tel.: +82-2704-8793 † These authors contributed equally. Abstract: Owing to its superior water absorption capacity, superabsorbent polymer (SAP) based on a poly (acrylic acid) network is extensively used in industrial products such as diapers, wound dressing, or surgical pads. However, because SAP does not degrade naturally, a massive amount of non-degradable waste is discarded daily, posing serious environmental problems. Considering that diapers are the most widely used end-product of SAP, we created one that is degradable by a human urinary enzyme. We chose three enzyme candidates, all of which have substrates that were modified with polymerizable groups to be examined for cleavable crosslinkers of SAP. We found that the urokinase-type plasminogen activator (uPA) substrate, end-modified with acrylamide groups at sufficient distances from the enzymatic cleavage site, can be successfully used as a cleavable crosslinker of SAP. The resulting SAP slowly degraded over several days in the aqueous solution containing uPA at a physiological concentration found in human urine and became shapeless in ~30 days. Citation: Whang, M.; Yu, H.; Kim, J. Keywords: biodegradable polymer; superabsorbent polymer (SAP); cleavable crosslinker; poly Superabsorbent Polymer Network (acrylic acid) (PAA); urokinase-type plasminogen activator (uPA) Degradable by a Human Urinary Enzyme. Polymers 2021, 13, 929. https://doi.org/10.3390/ polym13060929 1.
    [Show full text]
  • Thermal Polyaspartates
    do/- - *3 NEI-NO--774 Norske N09705205 1 Sivilingeniorers 7 Forening OIL FIELD CHEMICALS 7th international symposium 17-20 MARCH 1996 Dr Holms Hotel Geilo, Norway Biodegradable Multifunctional Oil Production Chemicals: Thermal Polyaspartates 15 LECTURERS: P D Ravenscroft, BP Exploration Operation Co Ltd, UK R J Ross, Donlar Corporation, USA Reproduction is prohibited unless permission from NIF or the Author DISCLAIMER Portions of this document may be Illegible in electronic image products. Images are produced from the best available original document i BIODEGRADABLE MULTIFUNCTIONAL OIL PRODUCTION CHEMICALS: THERMAL POLYASPARTATES. Robert J. Ross Donlar Corporation, USA Paul D. Ravenscroft BP Exploration Operating Company, Ltd, UK ABSTRACT Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensationof the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPA’s exhibit excellent mineral scale inhibition activity and C02 corrosion control. Laboratory data on scale inhibition and corrosion control in North Sea oil field production applications is presented. INTRODUCTION The impact of chemicals on the environment is an issue of increasing global importance. In sensitive areas, such as the North Sea, the need for “green” oil production and drilling chemicals is particularly acute. The effort to establishment of an international system of environmental controls under the Paris Commission (PARCOM) is a clear indication of the importance of environmental issues to the oil industry.
    [Show full text]
  • Polymerization of L-Aspartic Acid to Polysuccinimide and Copoly(Succinimide-Aspartate) in Supercritical Carbon Dioxide
    9259 Letters in Organic Chemistry, 2005, 2, 687-689 687 Polymerization of L-Aspartic Acid to Polysuccinimide and Copoly(Succinimide-Aspartate) in Supercritical Carbon Dioxide Kenneth M. Doll, 1 , Randal L. Shogren t2, Ronald A. Holser 1 , J.L. Willett2 and Graham Swift3 1 Food and Industrial Oil and 2Plant Polymer Research Units, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815 N. University St., Peoria, IL 61604, USA, 3Folia. Inc., 2800 Milan Court, Birmingham AL 35211 Received June 21, 2005: Revised August 21, 2005: Accepted September 05, 2005 Abstract: We have prepared two polymeric materials from L-aspartic acid in supercritical carbon dioxide, polysuccinimide and copoly(succinimide-aspartate). The polysuccinimide was characterized by JR spectroscopy and GPC analysis. The copoly(succinimide-aspartate) product was also characterized by titrometric analysis. These natural materials may prove useful in reducing our dependence on petroleum products. Keywords: Polysuccinimide, copoly(succinimide-aspartate), polyaspartic acid, supercritical carbon dioxide, natural polymer, amino acid polymer. The synthesis of polysuccinimide from L-aspartic acid, with or without acid catalysis (7-11]. It can also be Scheme (1) has a long history [1,2] L-aspartic acid or salts polymerized enzymatically [12]. The physical properties of of L-aspartate can be polymerized thermochemically [3-6], polysuccinimide have been studied, and found to be 0 0 OH )I NH No— OH HO (n+2) acid c at \\ 10 H2Nol L.,..,r:o 0 L OH Scheme 1. The synthesis of polysuccinimide from aspartic acid. 0 NH, )ç2 C N 4O +d Na 0 OrNa OH 0 -H2O -NH, H2N OH OH OH .iL o" idr Scheme 2.
    [Show full text]
  • Development and Research on a Green Scale Inhibitor for Circulating Cooling Water Xin-Ru Guo China Datang Corporation Science & Technology Research Institute Co., Ltd
    Advances in Engineering Research, volume 162 3rd International Conference on Advances in Materials, Mechatronics and Civil Engineering (ICAMMCE 2018) Development and Research on A Green Scale Inhibitor for Circulating Cooling Water Xin-ru Guo China Datang Corporation Science & Technology Research Institute Co., Ltd. Northwest BranchBranch Xi’an 710065 China Key words: green scale inhibitor; circulating cooling water; polyaspartic acid. Abstract: In this paper, a kind of green scale inhibitor for circulating cooling water for thermal power plants was studied. The optimum synthesis conditions were determined through experiments. The scale inhibition performance of green scale inhibitors was tested with the actual water of a power plant. Determining the best concentration of scale inhibitor. 1. INTRODUCTION Thermal power plants are large industrial water users, of which the thermal power plant cooling water accounts for the vast majority of its water, about 60% to 70%. Increasing the concentration rate of circulating cooling water can improve the utilization rate of water resources and achieve the purpose of water conservation, which is of great economic and environmental value for thermal power plants that are large water users. Increasing the concentration of circulating water, the key is used for circulating cooling water treatment scale inhibitor, [1]the development of high-performance scale inhibitor has significant economic benefits and important environmental benefits. At present, thermal power plants have been developed and developed
    [Show full text]
  • A Review and Perspectives on Aspartic Acid Production
    fermentation Review Sweet Dreams (Are Made of This): A Review and Perspectives on Aspartic Acid Production Holly Appleton and Kurt A. Rosentrater * Department of Agricultural and Biosystems Engineering, College of Engineering, Iowa State University, Ames, IA 50011, USA; hjapplet@ncsu.edu * Correspondence: karosent@iastate.edu Abstract: Aspartic acid, or “aspartate,” is a non-essential, four carbon amino acid produced and used by the body in two enantiomeric forms: L-aspartic acid and D-aspartic acid. The L-configuration of amino acids is the dominant form used in protein synthesis; thus, L-aspartic acid is by far the more common configuration. However, D-aspartic acid is one of only two known D-amino acids biosynthesized by eukaryotes. While L-aspartic acid is used in protein biosynthesis and neuro- transmission, D-aspartic acid is associated with neurogenesis and the endocrine system. Aspartic acid production and use has been growing in recent years. The purpose of this article is to discuss various perspectives on aspartic acid, including its industrial utility, global markets, production and manufacturing, optimization, challenges, and future outlook. As such, this review will provide a thorough background on this key biochemical. Keywords: bio-based; bio-chemicals; bio-materials; fermentation; synthesis Citation: Appleton, H.; Rosentrater, 1. Industrial Utility K.A. Sweet Dreams (Are Made of In addition to its biofunctionality, aspartic acid has wide application in the food, This): A Review and Perspectives on beverage, pharmaceutical, cosmetic, and agricultural industries [1]. L-aspartic acid is used Aspartic Acid Production. as a nutritional supplement in both functional foods and beverages, but its primary use Fermentation 2021, 7, 49.
    [Show full text]
  • Preparation of Ph-Responsive Poly(Aspartic Acid) Nanogels in Inverse Emulsion 2017 61 1 19 Molecular Weight, Which Depends on the Source of the Polymer
    PP Periodica Polytechnica Preparation of pH-Responsive Chemical Engineering Poly(aspartic acid) Nanogels in Inverse Emulsion 61(1), pp. 19-26, 2017 DOI: 10.3311/PPch.9788 Creative Commons Attribution b Enikő Krisch1, Benjámin Gyarmati1, András Szilágyi1* research article Received 23 July 2016; accepted after revision 23 August 2016 Abstract 1 Introduction Poly(aspartic acid) (PASP) hydrogels were prepared by cross- Hydrogels are commercialized in their bulk form in several linking polysuccinimide (PSI) with diaminobutane followed by medical devices and everyday applications, e.g. in implants, the mild hydrolysis of the resultant PSI gels to PASP hydro- contact lenses, diapers [1]. Besides these macroscopic appli- gels. The composition dependence of the gelation time and the cations the living cells can be targeted with nanogels (with stiffness of bulk PASP hydrogels were determined by rheome- diameter of few hundred nanometers) [2-4] since they have a try and compression tests, respectively. The composition of the large capacity for the entrapment of bioactive molecules such prepared PASP nanogels was chosen based on the results on as drugs, proteins, carbohydrates or DNA and can be taken bulk PASP hydrogels. Prior to nanogel preparation stability up by the cells if proper ligands (e.g. recognition factors) are of DMSO-in-oil (inverse) emulsions was tested as a function immobilized onto their surface [5, 6]. Well-known approaches of the chemical quality of apolar phase, the concentration of for preparing nanogels include photolithographic and micro- the precursor polymer and the concentration of the surfactant. molding techniques, microfluidics, free radical heterogeneous PASP nanogels in the size of a few hundred nanometers were polymerization in dispersion, nanoprecipitation and emulsion prepared by the hydrolysis of PSI nanogels synthesized in techniques [2, 7-9].
    [Show full text]
  • OIL FIELD CHEMICALS 7Th International Symposium
    Norske N09705205 Sivilingeniorers Ferening OIL FIELD CHEMICALS 7th international symposium 17 - 20 MARCH 1996 Dr Holms Hotel Geilo, Norway Biodegradable Multifunctional Oil Production Chemicals: Thermal Polyaspartates 15 LECTURERS! P D Ravenscroft, BP Exploration Operation Co Ltd, UK R J Ross, Donlar Corporation, USA Reproduction is prohibited unless permission from NIF or the Author DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. BIODEGRADABLE MULTIFUNCTIONAL OIL PRODUCTION CHEMICALS: THERMAL POLYASPARTATES. Robert J. Ross Donlar Corporation, USA Paul D. Ravenscroft BP Exploration Operating Company, Ltd, UK ABSTRACT Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPA's exhibit excellent mineral scale inhibition activity and CO2 corrosion control. Laboratory data on scale inhibition and corrosion control in North Sea oil field production applications is presented. INTRODUCTION The impact of chemicals on the environment is an issue of increasing global importance. In sensitive areas, such as the North Sea, the need for "green" oil production and drilling chemicals is particularly acute. The effort to establishment of an international system of environmental controls under the Paris Commission (PARCOM) is a clear indication of the importance of environmental issues to the oil industry. In order to meet the challenges of increasingly stringent regulations, the chemical industry has begun to develop production chemicals of lower environmental impact.
    [Show full text]