Addition Of Acrylic Acid Research Articles

CHEMICALLY CROSSLINKED CELLULOSE-BASED HYDROGEL PREPARED FROM RICE STRAW FOR THE REMOVAL OF AQUEOUS HEXAVALENT CHROMIUM ION FROM WASTEWATER

Then, this purified cellulose was co-polymerized by the addition of acrylic acid and ammonium persulfate in the presence of N,N-methylenebisacrylamide as crosslinker to form a cellulose-based hydrogel for the removal of hexavalent chromium (Cr(VI)) from wastewater. Here, the impact of various parameters, such as pH, contact time, material dosage, and initial solution concentration, on the adsorption capacity of the hydrogel for Cr(VI) ions is systematically investigated. The experimental findings revealed that the highest adsorption capacity for the treatment of Cr(VI)-containing water reached 1.1 mg Cr(VI)/g at pH 1, contact time of 120 min, and the initial concentration in the aqueous solution of 10 mg/L for an applied adsorbent dosage of 0.2 g. In addition, the equilibrium adsorption data agreed well with the Langmuir isotherm and the maximum adsorption amount was 4.14 mg Cr(VI)/g. Additionally, this material demonstrated good reusability, supporting the notion that it can be efficiently regenerated for multiple uses, a crucial factor for its practical application towards reducing the environmental impact and increasing its economic value.

Development of a fluorescent PMMA-based polymer material through in-situ incorporation of curcuma extract

In the present work, the in situ incorporation of curcumin was carried out in a polymer matrix through bulk polymerization to improve its photostability. It was found that extraction of curcumin from turmeric extract by the precursor monomer methyl methacrylate (MMA) can be performed immediately before the polymerization in order to reduce the degradation of the fluorescent species by the initiator system, although the obtained results also showed that incorporation of the turmeric extract into monomer can retard the polymerization kinetics. Despite that, the fluorescence properties of curcumin were preserved after incorporation in a solid polymeric matrix, which also enhanced the fluorophore photostability, avoiding the rapid degradation of the fluorophore observed when it is dispersed in solvents. Furthermore, it was also observed that addition of acrylic acid (AA) as a comonomer enhanced the photochemical stability of the turmeric extract incorporated into the polymer matrix and promoted the bathochromic effect, when compared to the spectroscopic behavior of the extract obtained from MMA, both in solution and solid state. It was possible to optimize the synthesis condition with help of a standard factorial experimental design, allowing the simultaneous attainment of high monomer conversion and fluorescence properties of the obtained material.

Cascading Beta-oxidation Intermediates for the Polyhydroxyalkanoate Copolymer Biosynthesis by Metabolic Flux using Co-substrates and Inhibitors

ABSTRACTPolyhydroxyalkanoates (PHAs) are biopolymers that are produced within the microbial cells in the presence of excess carbon and nutrient limitation. Different strategies have been studied to increase the quality and quantity of this biopolymer which in turn can be utilized as biodegradable polymers replacing conventional petrochemical plastics. In the present study, Bacillus endophyticus, a gram-positive PHA-producing bacterium, was cultivated in the presence of fatty acids along with beta-oxidation inhibitor acrylic acid. A novel approach for incorporating different hydroxyacyl groups provided using fatty acids as co-substrate and beta-oxidation inhibitors to direct the intermediates to co-polymer synthesis was experimented. It was observed that higher fatty acids and inhibitors had a greater influence on PHA production. The addition of acrylic acid along with propionic acid had a positive impact, giving 56.49% of PHA along with sucrose which was 1.2-fold more than the control devoid of fatty acids and inhibitors. Along with the copolymer production, the possible PHA pathway functional leading to the copolymer biosynthesis was hypothetically interpreted in this study. The obtained PHA was analyzed by FTIR and 1H NMR to confirm the copolymer production, which indicated the presence of poly3hydroxybutyrate-co-hydroxyvalerate (PHB-co-PHV), poly3hydroxybutyrate-co-hydroxyhexanoate (PHB-co-PHx).

Improved strength and water vapor permeability of polyacrylate/SiO2 nanocomposites: Molecular simulations and experimental analysis

The interfacial interactions between the filler and polymeric matrix determine the performance of composite materials and the chain structure of polymeric matrix renders an important influence on the interface performance. Herein, molecular dynamics (MD) simulations and experimental characterization are employed to study the effects of monomer composition and carbon branch chain length on the properties of polyacrylate/SiO2 nanocomposites from the viewpoint of interfacial interactions. The experimental results reveal that the addition of acrylic acid (AA) exhibits a positive influence on the strength and water vapor permeability, whereas the change in carbon branch length alters the strength of polyacrylate/SiO2 nanocomposites. The MD simulations unveil the underlying mechanism of these changes, i.e., the binding energy and diffusion coefficient (D). The current study clarifies the structure-property relationship of polyacrylate/SiO2 nanocomposites, providing a novel approach to design and optimize the interfacial properties of polyacrylate-based composites.

Prussian blue immobilized cellulosic filter for the removal of aqueous cesium

Cesium is a typical radioisotope that has a long half-life and is dangerous and can be emitted in the event of a nuclear accident. Prussian blue (PB), which is known to effectively adsorb cesium, is difficult to separate when it is dissolved in an aqueous system. In this study, PB was immobilized on a filter type support media, cellulose filter (CF), for use as a selective material for cesium adsorption. The commercially available CF was functionalized by the addition of acrylic acid (AA) (i.e., CF-AA) to enhance the PB immobilization, which increased both PB loading and binding strength. The AA functionalization changed the major functional groups from hydroxyl to carboxylic, as confirmed by Fourier-transform infrared spectroscopy. As a result of the surface modification, the PB immobilization increased 1.5 times and reduced detachment of PB during washing. The prepared adsorbent, CF-AA-PB, was tested for its cesium adsorption capability. Cesium adsorption equilibrated within 3 h, and the maximum cesium adsorption capacity was 16.66 mg/g. The observed decrease in the solution pH during cesium adsorption inhibited the overall cesium uptake; however, this was minimized by buffering. The prepared CF-AA-PB was used as a filter material and its potential use as a countermeasure for removing radioactive cesium from a contaminated water stream was demonstrated.

The Sulfonated Styrene-Acrylic Acid Copolymers with pH-Indicator Property

In this study, a polymer pH-indicator was synthesized by sulfonation of poly(styrene-co-acrylic acid) with concentrated sulfuric acid. The synthesized polymer pH-indicator exhibited pH-responsive color changes in aqueous solutions, being purple in alkaline medium (pH 9). The sulfonation process extent and polymer color were affected by time and temperature of the process, as well as acrylic acid (AA) content. The addition of acrylic acid was a crucial point for color change due to the facility of cyclic ketone structure to turn into phenol under acidic condition. Compared with low molecule pH-indicators, the sulfonated copolymer was prepared in form of films being repeatedly used as pH-indicator and easily removed from the acid-base medium.

Overproduction of MCL-PHA with high 3-hydroxydecanoate Content.

Methods of producing medium-chain-length poly-3-hydroxyalkanoate (mcl-PHA) with high content of the dominant subunit, 3-hydroxydecanoate (HD), were examined with an emphasis on a high yield of polymer from decanoic acid. High HD content was achieved by using a β-oxidation knockout mutant of Pseudomonas putida KT2440 (designated as P. putida DBA-F1) or by inhibiting β-oxidation with addition of acrylic acid (Aa) to wild type P. putida KT2440 in carbon-limited, fed-batch fermentations. At a substrate feed ratio of decanoic acid and acetic acid to glucose (DAA:G) of 6:4 g/g, P. putida DBA-F1 accumulated significantly higher HD (97 mol%), but much lower biomass (8.5 g/L) and PHA (42% of dry biomass) than the wild type. Both biomass and PHA concentrations were improved by decreasing the ratio of DAA:G to 4:6. Moreover, when the substrate feed ratio was further decreased to 2:8, 18 g/L biomass containing 59% mcl-PHA consisting of 100 mol% HD was achieved. The yield of PHA from decanoic acid was 1.24 (g/g) indicating that de novo synthesis had contributed to production. Yeast extract and tryptone (YET) addition allowed the mutant strain to accumulate 74% mcl-PHA by weight with 97 mol% HD at a production rate of 0.41 g/L/hr, at least twice that of published data for any β-oxidation knock-out mutant. Higher biomass concentration was achieved with Aa inhibition of β-oxidation in the wild type but the HD content (84 mol%) was less than that of the mutant. A carbon balance showed a marked increase in supernantant organic carbon for the mutant indicating overflow metabolism. Increasing the dominant monomer content (HD) greatly increased melting point, crystallinity, and rate of crystallization.

EPDM recycling assisted by γ-processing

The integration of waste ethylene–propylene–diene terpolymer (EPDM), containing carbon black into pristine EPDM can be achieved by γ-irradiation as a versatile procedure to process ethylene–propylene elastomers. The presence of acrylic acid in the material formulation allows the formation of intermolecular bridges by threefold increase in gel content. The possibility of achieving greater stability by the addition of acrylic acid in EPDM systems was analyzed. The start materials were EPDM containing 30 and 50 phr of EPDM powder loaded with 40 phr of carbon black aged by pre-exposure to electron beam irradiation. The advanced γ-irradiation exceeding 100 kGy represented the optimal radiation processing condition. Two procedures of chemiluminescence under isothermal and non-isothermal regimes for the evaluation of radiation stability were applied on γ-irradiated samples. The thermal strength of irradiated samples was characterized based on the radiolysis mechanism of EPDM. The variation in the activation energy required for the thermal oxidation of these samples and the modification in gel contents due to the gelation action of acrylic acid were presented for the validation of proposed recycling radiochemical technique. Charlesby–Pinner representation provided different values for the ratios between radiochemical yields of cross-linking and scission, proving that the presence of acrylic acid promoted the conversion of EPDM wastes into valuable materials.

Improvement of the characteristics of poly(acrylonitrile–butylacrylate) water-dispersed binder for lithium-ion batteries by the addition of acrylic acid and polystyrene seed

In this study, we modified an attractive water-dispersed poly(acrylonitrile–butylacrylate) binder used for lithium-ion batteries by the addition of highly acidic acrylic acid (AA). The synthesized poly(acrylicacid–acrylonitrile–butylacrylate)–polystyrene polymer showed an improved performance as a binder with smaller particle size, stiffer polymer matrix, higher adhesion strength, and lower contact angle characteristics. Consequently, the modified water-dispersed binder by the addition of AA increased the cyclic capacity and retention of physically mixed silicon/graphite anodes, when compared to the unmodified poly(acrylonitrile–butylacrylate) binder.

Preparation and characterization of hydrogels with potential for use as biomaterials

Hydrogels have been extensively explored for biomedical applications due to their ability to absorb high water content in its structure, which gives excellent biocompatibility. This work aims at obtaining biocompatible hydrogels with potential for use in increasing the mechanical strength of bone substitutes, or controlled drug release. Poly (N-vinyl-2-pyrrolidone) hydrogels were prepared by free radical polymerization with and without the addition of acrylic acid. Azobisisobutyronitrile and ammonium persulfate were used as initiator and N,N-methylenebisacrylamide was used as the crosslinking agent. The characterization of the hydrogels was performed by thermogravimetric analysis, differential scanning calorimetry, infrared spectroscopy and swelling properties. The results obtained demonstrate different degrees of crosslinking and swelling of up to 490 ± 30%. The different properties of the hydrogels suggest different applications.

높은 제타전위를 갖는 단분산의 블루착색 고분자미립자의 제조

2단계 유화중합에 의한 단분산의 블루칼라 착색 poly(styrene-co-acrylic acid) 라텍스를 성공적으로 제조하였다. 0.21 <TEX>${\mu}m$</TEX>의 polystyrene 시드를 이용하여 중합 2단계에서 Blue 606 염료와 acrylic acid의 중합으로 carboxyl 음이온을 갖는 블루칼라 라텍스를 합성하였다. 본 연구에서 제조한 블루칼라 라텍스는 모두 1.01 이하의 우수한 단분산도를 가지며 0.25~0.42 <TEX>${\mu}m$</TEX> 범위의 입자경을 나타내었다. 중합 2단계에서 acrylic acid 부가시간이 늘어남에 따라 입자경은 증가하였고 30 min 이상으로 늘어남에 따라 콜로이드 안정성을 갖는 블루칼라 라텍스가 제조되었다. 20 wt% AA 농도에서 -145 mV의 제타전위와 <TEX>$-9.4{\times}10^{-6}\;cm^2/Vs$</TEX>의 전기영동이동도를 나타내었다. 25 wt% DVB 농도하에서 396.7 K의 높은 유리전이온도를 나타내었다. Monodisperse blue-colored poly(styrene-co-acrylic acid) latices were successfully prepared by seeded emulsion polymerization. Blue-colored latices with carboxyl anionic charge on the surface were synthesized at the second stage with the introduction of Blue 606 dye, acrylic acid, and 0.21 <TEX>${\mu}m$</TEX>-polystyrene seed. All the blue-colored latices synthesized in this study were in the size range of 0.25~0.42 <TEX>${\mu}m$</TEX> and all uniform with less than 1.01 in PSD. The particle size increased with the addition of acrylic acid being delayed and colloidally stable latices were obtained over 30 min after its addition. The blue-colored latex with 20 wt% acrylic acid showed -145 mV of zeta-potential and <TEX>$-9.4{\times}10^{-6}\;cm^2/Vs$</TEX> of electrophoretic mobility, and with 25 wt% of DVB showed high <TEX>$T_g$</TEX> at 396.7 K.

Synthesis of acrylates based on tetracyclododecene and its methyl derivative

The reaction of catalytic and thermal addition of acrylic acid to tetracyclo[4.4.12,5.17,10.01,6]dodec-3-en and its 8-methyl-substituted derivative was studied. The reaction is intended for the synthesis of corresponding acrylates, which are reactive monomers suitable for producing high-molecular compounds.

Solventless UV crosslinkable acrylic pressure sensitive adhesives

The synthesis and characterization of solventless acrylic UV crosslinkable pressure sensitive adhesives are presented. Different prepolymers were synthesized using bulk polymerization procedure. The reaction mixture consisted of acrylic monomers (2-ethylhexyl acrylate, acrylic acid and t-butyl acrylate), azobisisobutyronitrile initiator, chain transfer agent n-dodecylmercaptan and unsaturated UV photoinitiator 4-acryloyloxybezophenone, which was copolymerized into polymer backbone. Different formulations were tested and the prepolymer was characterized by viscosity measurements and final monomer conversions. The prepolymers were coated onto PET foil and crosslinked by application of UV light source. Peel adhesion at 180° on glass plate was measured. Gel phase was determined using the Soxhlet extraction and copolymer glass transition temperatures ( T g ) were analyzed by differential scanning calorimetry (DSC). Results showed that the final monomer conversions in highly exothermic bulk polymerization reached a level between 75% and 90%. Prepolymer viscosity was highly influenced by change in polymer molecular weight and by addition of acrylic acid as a comonomer. On the other hand, the viscosity remained at the low level when t-butyl acrylate was used. The amount of gel phase for all adhesives was above 60 wt.%. Peel strength measurements showed decrease in peel strength with decreasing polymer molecular weight and increase of peel, when acrylic acid was used as a comonomer. All adhesive coatings with t-butyl acrylate comonomer showed cohesive failure.

Synthesis of acetic-methacrylic acid diesters of norbornane-2,5-diol and (2-hydroxynorborn-5-yl)methanol

Reaction of addition of acrylic acids to 5-acetoxy- and 5-acetoxymethylnorborn-2-ene in the presence of a BF3·O(C2H5)2 catalyst was studied in order to synthesize mixed acetic-acrylic acid diesters of norbornane-2,5-diol and (2-hydroxynorborn-5-yl)methanol, which are new monomers for syntheses of polymers.

Synthesis of new monomers, cyanomethylnorbornyl acrylates

The [4+2]-cycloaddition of cyclopentadiene to methacrylonitrile and addition of acrylic acids to the resulting exo-2-cyano-endo-2-methylnorborn-5-ene were studied. The possibility was explored of synthesizing cyano-containing bicyclic acrylates suitable as reactive monomers for preparation of polymeric products.

Characterization and Properties of Hydrophilic Cellulose Acetate Propionate Derivative

The chemical modification of Acrylamidomethyl Cellulose Acetate Propionate (AMCAP) was carried out by radical addition of acrylic acid. The structural modification was confirmed with the aid of FTIR, MS and NMR techniques. Thermal properties of hydrophilic cellulose derivative (AMCAP–H2O2) such as glass transition (Tg 153 °C) and thermal stability (372.7 °C) were determined by DSC and TGA techniques, respectively. These thermal properties confirmed the introduction of carboxylic groups into AMCAP structure, which causes an impact in their properties. The AMCAP–H2O2 shows minor contact angle compared to AMCAP, giving a more hydrophilic characteristic, due to acrylic acid addition into the side chains of AMCAP polymer.

Manipulating Degradation Time in a N-isopropylacrylamide-Based Co-polymer with Hydrolysis-Dependent LCST

A thermosensitive, bioresorbable and in situ gelling co-polymer, poly(N-isopropylacrylamide-co-dimethyl-γ-butyrolactone acrylate-co-acrylic acid), was synthesized by radical co-polymerization with varying dimethyl-γ-butyrolactone acrylate (DBA) content. The materials properties were characterized using differential scanning calorimetry, gel-permeation chromatography in conjunction with static light scattering, Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and acid titration. The initial lower critical solution temperature (LCST) of the synthesized co-polymer is between room temperature and body temperature. With the increase of DBA content, the LCST decreases, but then increases after the ring-opening hydrolysis of the DBA side-group. The FT-IR and NMR spectra show the co-polymerization of three monomers, as well as the hydrolysis-dependent ring-opening of the DBA side-group. The addition of acrylic acid increases the initial LCST and accelerates the degradation rate of the co-polymer. An indirect cytotoxicity test indicated that this co-polymer has relatively low cytotoxicity as seen with 3T3 fibroblast cells.

Latex film performance of styrene–acrylic particles functionalized with acrylic acid

AbstractLatex polymers are frequently used as substitutes for solvent‐borne coatings in environmental friendly technologies. However, the relationship between the copolymer composition and the latex film performance must be established. The preparation of a series of styrene–n‐butyl acrylate latexes functionalized with different amounts of acrylic acid through semicontinuous emulsion polymerization is presented. In this work, latexes were employed to study the modification of the latex film properties by the addition of acrylic acid during the polymerization; mainly, the adhesion to the substrate, the water vapor permeability, and the electrical film resistance were examined. The most advantageous acrylic acid content was established by a balance of the tested properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Biosynthesis of polyhydroxyalkanoates co-polymer in E. coli using genes from Pseudomonas and Bacillus

Expression of Pseudomonas aeruginosa genes PHA synthase1 (phaC1) and (R)-specific enoyl CoA hydratase1 (phaJ1) under a lacZ promoter was able to support production of a copolymer of Polyhydroxybutyrate (PHB) and medium chain length polyhydoxyalkanoates (mcl-PHA) in Escherichia coli. In order to improve the yield and quality of PHA, plasmid bearing the above genes was introduced into E. coli JC7623, harboring integrated beta-ketothiolase (phaA) and NADPH dependent-acetoacetyl CoA reductase (phaB) genes from a Bacillus sp. also driven by a lacZ promoter. The recombinant E. coli (JC7623ABC1J1) grown on various fatty acids along with glucose was found to produce 28-34% cellular dry weight of PHA. Gas chromatography and (1)H Nuclear Magnetic Resonance analysis of the polymer confirmed the ability of the strain to produce PHB-co-Hydroxy valerate (HV)-co-mcl-PHA copolymers. The ratio of short chain length (scl) to mcl-PHA varied from 78:22 to 18:82. Addition of acrylic acid, an inhibitor of beta-oxidation resulted in improved production (3-11% increase) of PHA copolymer. The combined use of enzymes from Bacillus sp. and Pseudomonas sp. for the production of scl-co-mcl PHA in E. coli is a novel approach and is being reported for the first time.

Discovery of a unique dual response in acrylonitrile copolymers

Poly(acrylonitrile) is not reversibly sensitive to either changing temperature or changingpH. However, the addition of acrylic acid (AA) as a comonomer induces the pH response tothis polymer. In this study, for the first time, the copolymers of acrylonitrile and acrylicacid were shown to possess a unique dual response to pH and temperature. For this, aseries of acrylonitrile-based copolymers were synthesized with varying AA contentfrom 10 to 50 mol% using free radical copolymerization. These copolymers weresolution-spun from a DMF–water system and heat-set to give stable fine fibers of120 ± 3 µ diameter without any chemical crosslinking. The fibers showed temperature sensitivity in anaqueous alkaline bath. At pH 10, the volumetric swelling of fibers containing 30 mol% of AAinitially increased from 3810% to 6440% with increase in temperature of the bath from 30 to49 °C,and suddenly decreased to 4200%, near to the original swelling level, when the temperature reached50 °C. The copolymer was found to have a clear and sharp transition temperature between 49 and50 °C.The behavior shown was unlike other temperature-responsive polymers, where it is a step transitionfrom the swollen to deswollen state. The transition temperature could be tuned in the range of 40 to62 °C by varying the composition of acrylic acid from 10 to 50 mol% in the copolymers.The transition temperature was also found to increase with increasing pH of thesurrounding bath. All transitions were reversible and stable to repeated cycling.