- Enzyme-induced formation of thermoreversible micellar gels from aqueous solutions of multiresponsive hydrophilic ABA triblock copolymers
-
We report on the synthesis of thermo- and enzyme-responsive hydrophilic ABA triblock copolymers, poly(ethoxydi(ethylene glycol) acrylate-co-4- ((dihydroxyphosphoryl)oxy)butyl acrylate)-b-poly(ethylene oxide)-b- poly(ethoxydi(ethylene glycol) acrylate-co-4-((dihydroxyphosphoryl)oxy)butyl acrylate) (P(DEGEA-co-OPBA)-b-PEO-b-P(DEGEA-co-OPBA)), and the enzyme-induced formation of thermoreversible micellar gels from their moderately concentrated aqueous solutions at 37 °C. PDEGEA is a thermosensitive water-soluble polymer with a lower critical solution temperature (LCST) at 9 °C in water. The block copolymers were prepared by atom transfer radical polymerization of DEGEA and 4-((di-tert-butoxyphosphoryl)oxy)butyl acrylate and subsequent removal of tert-butyl groups. To seek optimal conditions for enzymatic gelation of aqueous solutions of triblock copolymers, a study of dephosphorylation of a random copolymer P(DEGEA-co-OPBA) by acid phosphatase in water at 37 °C was carried out. The time for the solution to turn cloudy was found to decrease with the decrease of pH from 5.48 to 4.70 and level off from pH 4.39 to 4.23. The cleavage of phosphate groups made the polymer less hydrophilic and decreased the LCST from above to below 37 °C. Therefore, pH 4.4 was selected to conduct the enzyme-induced gelation of 7.9 wt % aqueous solutions of P(DEGEA-co-OPBA)-b-PEO-b-P(DEGEA-co-OPBA). The gelation processes were monitored by rheological measurements; the sol-gel transition temperature decreased and the gel strength increased with the increase of reaction time. The gels formed were thermoreversible; lowering temperature converted the gels to free-flowing liquids. From 1H and 31P NMR spectroscopy analysis, the degree of dephosphorylation was high. The formation of three-dimensional micellar network gels stemmed from the thermosensitive properties of the resultant dephosphorylated triblock copolymers, which was confirmed by a dynamic light scattering study. At a slightly higher pH (4.67), the enzyme-induced gelation was significantly slower, consistent with the observation of the effect of pH on dephosphorylation of the random copolymer by acid phosphatase.
- Woodcock, Jeremiah W.,Jiang, Xueguang,Wright, Roger A. E.,Zhao, Bin
-
-
Read Online
- Runge-Kutta analysis for optimizing the Zn-catalyzed transesterification conditions of MA and MMA with diols to maximize monoesterified products
-
Terminal hydroxylated acrylates and methacrylates were prepared by catalytic transesterification of acrylates and methacrylates with diols catalyzed by a system of a tetranuclear zinc alkoxide, [Zn(tmhd)(OMe)(MeOH)]4 (1a), with 4 equiv. of 2,2′-bipyridine (L1). The reaction time to reach the equilibrium state was analyzed by kinetic studies and a curve-fitting analysis based on the Runge-Kutta method for optimizing the best reaction conditions for mono-esterification. In addition to these kinetic analyses, DFT calculations estimated a proposed mechanism of the catalytic transesterification. This journal is
- Akebi, Shin-Ya,Kato, Taito,Mashima, Kazushi,Nagae, Haruki,Oku, Tomoharu,Yonehara, Koji
-
p. 6975 - 6986
(2021/11/17)
-
- Acrylate monomer having hydrophilic end group and a method for preparing the same
-
More particularly, the present invention relates to an acrylate monomer having a high-purity hydrophilic terminal group which does not contain unreacted 1 water or undesirable by-products, and a method for producing the acrylate monomer. These acrylate monomers are substantially free of polymerization inhibitors. Chemical Formula 1. In Chemical Formula 1, R. 1 Chem. R. 2 Chem. R. 3 May be H, or linear, branched or cyclic C, independently of each other. 1 -C12 alkyl group. R4 Is linear, branched or cyclic C. 1 -C12 alkyl Or C1 -C12 It is alkoxy group, wherein alkyl group carbon atoms can be unsubstituted or substituted with oxygen atoms, n Is an integer selected from 1 and 10.
- -
-
Paragraph 0120-0122
(2021/11/02)
-
- Synthesis method of 4-hydroxy butyl acrylate
-
The invention belongs to the field of synthesis process development of photocuring diluents, and particularly relates to a synthesis method of 4-hydroxy butyl acrylate. The synthesis method of the 4-hydroxy butyl acrylate provided by the invention comprises the following steps: carrying out dehydration condensation cyclization on 1, 4-butanediol and acrolein under the catalytic action of a strong acid catalyst to obtain 2-vinyl-1, 3-dioxoheptacyclic ring, and then carrying out oxidation ring opening on the 2-vinyl-1, 3-dioxoheptacyclic ring under the action of ozone to obtain the 4-hydroxy butyl acrylate. The synthesis method of 4-hydroxy butyl acrylate provided by the invention has the advantages that the method is simple and convenient, the efficiency is high, and the obtained 4-hydroxy butyl acrylate product is high in purity and hydroxyl value, so that popularization and application of the synthesis method of 4-hydroxy butyl acrylate are facilitated.
- -
-
Paragraph 0043; 0046; 0047; 0050; 0051; 0054
(2021/11/21)
-
- Oxidative Deprotection of p-Methoxybenzyl Ethers via Metal-Free Photoredox Catalysis
-
An efficient and greener deprotection method for p-methoxybenzyl (PMB) ethers using a metal-free visible light photoredox catalyst and air and ammonium persulfate as the terminal oxidants is presented. Various functional groups and protecting groups were tolerated in the developed method to achieve good to excellent yields in short reaction times. Significantly, the developed method was compatible with PMB ethers derived from primary, secondary, and tertiary alcohols and a gram-scale reaction. Mechanistic studies support a proposed reaction mechanism that involves single electron oxidation of the PMB ether.
- Ahn, Deok Kyun,Kang, Young Woo,Woo, Sang Kook
-
p. 3612 - 3623
(2019/03/11)
-
- Method for preparing 4-hydroxybutyl acrylate by means of extraction and separation
-
The invention relates to a method for preparing 4-hydroxybutyl acrylate by means of extraction and separation. The method is characterized by comprising the following steps: (1) putting 1, 4-butanediol, a catalyst, a polymerization inhibitor and a solvent into a reactor to form mixed liquid; (2) slowly heating and controlling the temperature to be 40-60 DEG C, and dropwise adding acrylic acid containing a certain amount of the polymerization inhibitor for 30-50min at the temperature; (3) continuously and slowly heating and controlling the temperature to be 100-120 DEG C, carrying out a refluxreaction for 2-5h reaction and then finishing the reaction; (4) adding aqueous solution into the mixed liquid and then adding a certain amount of extractant for firstly extracting 1, 4-butanediol diacrylate from an aqueous phase; (5) extracting the 4-hydroxybutyl acrylate from the aqueous phase by using an extractant; (6) distilling under reduced pressure to obtain a finished product. The productof the method is colorless and does not need to be faded, so that the aftertreatment process is simpler, and the quality and yield of the final product are increased.
- -
-
Paragraph 0033-0076
(2019/01/14)
-
- A through extraction separation preparation 4 - acrylic acid [...] production process and apparatus (by machine translation)
-
The invention relates to a method for extracting and separating preparation 4 - acrylic acid [...] production process and apparatus, will be 1, 4 - butanediol and acrylic acid in the catalyst, and the presence of a solvent polymerization reaction, the major product is 4 - acrylic acid [...] and 1, 4 - butanediol diacrylate; selects the first extracted from the aqueous phase in the cyclohexane 1, 4 - butanediol diacrylate, then choosing methylene chloride from the aqueous phase extraction 4 - acrylic-acid [...], finally distilled under reduced, to make the finished product. The beneficial effect of the present invention is: through the reaction section and separation section of each component physical property, content and the like, has designed a set of process flow, and through the process flow to obtain the final product 4 - acrylic acid [...], purity in full compliance with the requirements of industrial production. The technique of the invention is simple, the required low energy consumption, low production cost, the prepared product having high purity and yield of the product is high, good quality. (by machine translation)
- -
-
Paragraph 0005; 0028
(2019/01/14)
-
- METHOD FOR PRODUCING HYDROXYALKYL(METH)ACRYLIC ACID ESTER
-
PROBLEM TO BE SOLVED: To provide a production method that permits efficient production of a hydroxyalkyl (meth)acrylate of high purity without necessitating a troublesome purification step.SOLUTION: The production method for a hydroxyalkyl (meth)acrylate comprises (meth)acrylating a vinyl ether-containing alcohol by a transesterification method to obtain a vinyl ether-containing (meth)acrylate, carrying out a devinylation reaction in the presence of an acid catalyst and water, and subsequently carrying out a deacetalization reaction by further adding water.
- -
-
Paragraph 0073; 0076; 0077
(2018/01/11)
-
- PROCESS FOR PREPARING 4-HYDROXYBUTYL ACRYLATE
-
A process for preparing 4-hydroxybutyl acrylate by transesterifying an alkyl acrylate with 1,4-butanediol in the presence of a dialkyltin oxide such that each of the alkyl groups has 4 to 8 carbon atoms, characterized in that the amount of the dialkyltin oxide is adjusted to 0.00001 to 0.01 moles per one mole of the alkyl acrylate.
- -
-
Paragraph 0455; 0456; 0457; 0458; 0459; 0460
(2015/04/22)
-
- Synthesis of glycopolymers at various pendant spacer lengths of glucose moiety and their effects on adhesion, viability and proliferation of osteoblast cells
-
Multivalent glycopolymers containing three different glucose pendant spacer lengths in the polymer backbone having various weight percentages of covalently bonded glucose moieties were obtained by the deacetylation of acetylated polymers synthesized via reversible addition-fragmentation chain transfer (RAFT) process. This allowed us to control the packing density of the glucose moieties in one unit of the glycopolymer. The biological responses of these macromolecules in terms of cytotoxicity of glucose moieties at various spacer lengths and concentrations were investigated without perturbing the intrinsic chemical nature of functional moiety by employing in vitro osteoblast cells. Osteoblast cell adhesion, viability and proliferation response with synthesized glycopolymers revealed that the higher glycopolymer concentration tolerance limit was associated with an increase in pendant spacer length of glucose moiety in the glycopolymer. the Partner Organisations 2014.
- Trinadh, Mummuluri,Kannan, Govindaraj,Rajasekhar, Tota,Sesha Sainath, Annadanam V.,Dhayal, Marshal
-
p. 37400 - 37410
(2014/11/27)
-
- Hydroxy functional acrylate and methacrylate monomers prepared via lipase-catalyzed transacylation reactions
-
Candida antarctica lipase B (CAL-B, Novozyme 435) catalyzes the transacylation of methyl acrylate and methyl methacrylate with diols and triols in 2-methyl-2-butanol at 50 °C. Under the experimental conditions, up to 70 mol% of the acyl donor methyl acrylate was converted. Methyl methacrylate is the less efficient acyl donor (up to 60 mol%) due to the higher sterical hindrance in the enzymatic transacylation. Under the reaction conditions high yields of the mono-acylated products are obtained, which contain minor amounts of bis(meth)acrylates. In addition it was observed that Novozyme 435 catalyzes regioselectively the acylation of the primary hydroxyl groups. In comparison with the chemical catalyzed route no selectivity was observed for unsubstituted diols. For substituted diols more mono-acylated product was formed in the lipase-catalyzed reaction than in the chemical catalyzed reaction.
- Popescu, Dragos,Hoogenboom, Richard,Keul, Helmut,Moeller, Martin
-
experimental part
p. 80 - 89
(2010/08/20)
-
- Free radical and nitroxide mediated polymerization of hydroxy-functional acrylates prepared via lipase-catalyzed transacylation reactions
-
3-Hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 2-methyl-3-hydroxypropyl acrylate, 2-hydroxypropyl acrylate, neopentyl glycol acrylate, glyceryl acrylate, and dihydroxyhexyl acrylate were prepared via transacylation reaction of methyl acrylate with diols and triols catalyzed by Candida antarctica lipase B. After removal of the enzyme by filtration and the methyl acrylate by distillation, the monomers were polymerized via free radical polymerization (FRP) with azobisisobutyronitrile as initiator and nitroxide mediated polymerization (NMP) employing Blocbuilder alkoxyamine initiator and SG-1 free nitroxide resulting in hydroxy functional poly(acrylates). The NMP kinetics are discussed in detail. In addition, the polymers obtained by FRP and NMP are compared and the results are related to the amount of bisacrylates that are present in the initial monomer mixtures resulting from the transacylation reactions
- Popescu, Dragos,Hoogenboom, Richard,Keul, Helmut,Moeller, Martin
-
experimental part
p. 2610 - 2621
(2011/04/22)
-
- Acrylic-based adhesive composition
-
An Adhesive composition for us in surgery, especially ophthalmic surgery, comprises a mixture of a cyanoacrylate of general formula (I) and an acrylate compound of formula (II) where R4 is an alkylene group and Y is a cycloalkyl group or Y═OR where R═H or acryloyl. It is found that compositions of this type have a number of advantages over simple cyanoacrylate adhesives, including: (a) a longer cure time, allowing easier handling of the joint; (b) a more flexible cured product; (c) a tendency for the cured to come away from the tissue after a month or so thus facilitating healing; and (d) a substantially non-exothermic curing reaction, thereby avoiding thermal damage to the tissue.
- -
-
-
- Process for the conversion of aldehydes to esters
-
A process for the conversion of aldehydes to esters, specifically acrolein or methacrolein to methyl acrylate or methyl methacrylate, respectively. Essentially in the absence of water, an aldehyde is contacted with an oxidizing agent to form an intermediate and then the intermediate is contacted with a diol or an alcohol to form an ester or diester. Preferably, the oxidizing agent is also a chlorinating agent. Specifically, acrolein or methacrolein is contacted with an oxidizing/chlorinating agent, such as t-butyl hypochlorite, and the chlorinated compound is contacted with an alcohol, such as methanol, to form methyl acrylate or methyl methacrylate, respectively. Generally, the order of addition is for the oxidizing agent to be added to the aldehyde, specifically for t-butyl hypochlorite to be added to acrolein or methacrolein, and for the diol or alcohol to be added to the intermediate, specifically for the methanol to be added to the reaction product of acrolein or methacrolein and t-butyl hypochlorite. The process of the present invention can be carried out in the absence or in the presence of solvent. Generally, better methyl acrylate or methyl methacrylate yields are obtained at lower reaction temperatures.
- -
-
Page/Page column 3-4
(2010/01/31)
-
- A new carboxylesterase from Brevibacterium linens IFO 12171 responsible for the conversion of 1,4-butanediol diacrylate to 4-hydroxybutyl acrylate: Purification, characterization, gene cloning, and gene expression in Escherichia coli
-
A carboxylesterase that is responsible for conversion of 1,4-butanediol diacrylate (BDA) to 4-hydroxybutyl acrylate (4HBA) was found in Brevibacterium lines IFO 12171, and purified to homogeneity. The purified enzyme was active toward a variety of diesters of ethylene glycol, 1,4-butanediol, and 1,6-hexanediol. The Km and kcat of the enzyme for BDA were 3.04 mM and 203,000 s-1, respectively. The reaction with the purified enzyme gave 98 mM 4HBA from 100 mM BDA for 60 min. The enzyme gene was cloned from the chromosomal DNA of the bacterium. The open reading frame encoding the enzyme was 1176 bp long, corresponding to a protein of 393 amino acid residues (molecular mass=42,569Da). The deduced amino acid sequence contained the tetra peptide motif sequence, STTK, and the serine residue was confirmed to be the catalytic center of BDA esterase by site-directed mutagenesis for several amino acid residues. The gene was expressed in Escherichia coli under the control of the lac promoter, and the gene product (a fusion protein with 6 amino acid residues from β-galactosidase) showed the same catalytic properties as the enzyme from the parent strain.
- Sakai, Yasuyoshi,Ishikawa, Junko,Fukasaka, Shunji,Yurimoto, Hiroya,Mitsui, Ryoji,Yanase, Hideshi,Kato, Nobuo
-
p. 688 - 697
(2007/10/03)
-
- Method for producing 4-hydroxybutyl (meth)acrylate
-
4-Hydroxybutyl (meth)acrylate is prepared by reacting (meth)acrylic acid with 1,4-butanediol in the presence of an acidic catalyst. 1,4-Butanediol di(meth)acrylate is added at the beginning of the reaction and the ratios of the butanediol to the acid and of the ester to the acid are kept within specified ranges during the course of the reaction.
- -
-
-
- High solids acrylic coating systems
-
High solids acrylic coating compositions are formulated by using as a reactive diluent, a low molecular weight hydroxyl-containing acrylic polymer. These polymers are prepared at about 15°-20° C. with anionic initiator concentrations greater than about 5 mole percent.
- -
-
-
- FIBROUS POLYMERIC COMPOSITES IMMOBILIZING GLUCOSE OXIDASE
-
Fibrous polymeric composites immobilizing glucose oxidase have been prepared by the radiation polymerization of various glass-forming monomers at low temperatures.The radiation polymerization of the monomer solution containing the enzymes and fibrous material was studied as a function of the irradiation temperature, at which the polymerization rate and enzyme activity had optimum values.The nature of the monomer, monomer concentration and the thickness of the polymer matrix on the fibrous material was shown to affect the enzyme activity of the composites.
- Kumakura, M.,Kojima, T.,Kaetsu, I.
-
-