Acrylic Acid Content Research Articles

Effect of adhesive thickness on the wettability and deformability of polyacrylic pressure‐sensitive adhesives during probe tack test

ABSTRACTEffect of adhesive thickness on the wetting and deformation behaviors during probe tack test of pressure‐sensitive adhesive (PSA) was investigated. For this purpose, cross‐linked poly(n‐butyl acrylate‐acrylic acid) [P(BA‐AA)] and poly(2‐ethylhexyl acrylate‐acrylic acid) [P(2EHA‐AA)] random copolymers with an acrylic acid content of 5 wt % and thicknesses in the range of ∼15–60 μm were used. Tack was measured using the probe tack test and the fracture energy was calculated from the areas under force–displacement curve recorded during debonding process. From contact time dependence of fracture energy, the rising rate of fracture energy with contact time increased with increasing of adhesive thickness and was P(2EHA‐AA) > P(BA‐AA). The fracture energy was P(BA‐AA) > P(2EHA‐AA) at shorter contact time, whereas it reversed at longer contact time. This was caused by two different interfacial adhesions: the physical wetting of PSA molecules to the adherend surface with contact time and the chemical interaction between the acrylic acid units and the adherend surface. From the force–displacement curve measured under the condition of sufficient interfacial adhesion, both maximum force and displacement—namely, the deformability of PSA during debonding process—increased with adhesive thickness. The degree of increase of deformability was P(2EHA‐AA) > P(BA‐AA). The fracture energy was found to depend on the development of interfacial adhesion during contacting process and the deformability of PSA during debonding process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43639.

Immobilizing Bacillus subtilis on the carrier of poly (acrylic acid)/sodium bentonite for treating sludge from Pangasius fish ponds

Sodium bentonite (NaBent) was modified by poly(acrylic acid) (PAAc) to prepare the carriers for immobilization of Bacillus subtilis. Different mixtures of NaBent/AAc were regularly dispersed in distilled water and irradiated under gamma rays at an absorbed dose of 6.5 kGy with dose rate of 0.85 kGy/hr in air for polymerization of acrylic acid and formation of poly(acrylic acid)/sodium bentonite (PAAc–NaBent). The reaction yield was determined with the initial concentration of acrylic acid (AAc). The functional group properties of the resulting PAAc–NaBent were analyzed by Fourier Transform Infrared spectra (FTIR). Bacillus subtilis cells were immobilized on both NaBent and PAAc–NaBent as carriers by adsorption method for treating the sludge contaminated by fish feces and residual feed from the Pangasius farming ponds. The results showed that immobilization capacity of Bacillus subtilis on the PAAc–NaBent was better than that on non-modified NaBent. Analysis of BOD for the farming pond water containing Bacillus subtilis and the bacteria immobilized carriers with time revealed the lower BOD values obtained with the samples containing PAAc–NaBent, suggested that degradation of organic pollutants by Bacillus subtilis immobilized on the PAAc–NaBent was faster than that by free bacteria.

Superabsorbentmaterials from grafting of acrylic acid onto Thai agricultural residues by gamma irradiation

ABSTRACTSuperabsorbent polymers based on ubiquitous agricultural residues: sugarcane, water hyacinth, rice straw, coconut shell and palm fruit bunch substrates, were successfully synthesized. Gamma radiation from Co-60 was employed to graft acrylic acid (AA) onto the substrates. Rice straw exhibited the highest equilibrium swelling ratio of 78.90 g/g at 6 kGy of absorbed gamma ray dose and 14%v/v AA concentration. The rate of water absorption was rapid at the beginning and became reduced with increasing immersion time. After about 3.5 hours, the absorption reached approximately 90% of the saturation value. Temperature plays a critical role on the rate of water evaporation from the superabsorbent. As for the one experiencing 35 °C–40 °C temperature, the weight of the saturated superabsorbent reduced to approximately 50% of the original value in 13 hours. However, for the one experiencing room temperature (24.2 °C–27.7 °C), approximately 58 hours were needed to reduce the weight by half. The superabsorbent polymer was able to absorb about 203% of the polymer's dry weight and did not release urea when eluded by water. Moreover, the polymer was able to hold water very well for at least 3 weeks and did not degrade until at least 6 weeks, ensuring biodegradability.

Quaternized Chitosan/Poly(acrylic acid) Polyelectrolyte Complex Hydrogels with Tough, Self-Recovery, and Tunable Mechanical Properties

Quaternized chitosan (QCh) was homogeneously synthesized by reacting chitosan with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) in alkali/urea aqueous solution for the first time. The structure and solution properties of QCh were characterized by using element analysis, FT-IR, 13C NMR, SEC-LLS, rheology, viscometer, and ξ-potential measurements. Subsequently, polyelectrolyte complex (PEC) hydrogels were constructed by in situ polymerization of acrylic acid (AA) monomers in the concentrated QCh solution. The structure and mechanical behavior of the prepared hydrogels were systematic studied. Because of the high charge density and solubility of QCh, strong electrostatic interactions were formed in the hydrogels and endowed them tough with self-recovery properties. The mechanical behavior of the hydrogels was accurately tuned from stiff and viscoelastic to soft and elastic by changing the poly(acrylic acid) (PAA) content. The regulation mechanism relied on the remarkable difference in the chai...

Synthesis and characterization of cetirizine‐containing, pH‐sensitive acrylic acid/poly(vinyl alcohol) hydrogels

ABSTRACTIn this study, interpenetrated acrylic acid (AA)/poly(vinyl alcohol) (PVA) hydrogels were prepared by free‐radical polymerization with N,N‐methylene bisacrylamide (MBAAm) as a crosslinker. The basic structural parameters, such as the molecular weight between crosslinks, volume interaction parameter, number of crosslinks, Flory–Huggins solvent interaction parameter, and diffusion coefficient, were calculated. Cetirizine dihydrochloride was loaded as a model drug in selected samples. The prepared hydrogels were evaluated for swelling, sol–gel fraction, and porosity. The swelling of the AA/PVA hydrogels was found to be directly proportional to the pH, that is, 1.2–7.5, depending on composition. The percentage of cetirizine hydrochloride was found to be directly proportional to the buffer pH and was at its maximum at pH 7.5, that is, 90–95%, and its lowest at pH 1.2, that is, 20–30%. The gel fraction increased with increasing concentration of AA and MBAAm, whereas the porosity showed the same response with AA, but an inverse relationship was observed with MBAAm. The drug‐release data were fitted into various kinetics models, including the zero‐order, first‐order, Higuchi, and Peppas models, which showed non‐Fickian diffusion. The prepared hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, and no interaction was found among the polymer ratio and the drug. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43407.

Colloidal Hydroxyapatite/Poly(Acrylic Acid) Hybrids Using Calcium Sucrate and Ammoniumdihydrogen Orthophosphate

This manuscript is concerned with a simple and novel method to synthesize hydroxyapatite-poly(acylic acid) hybrid materials for broad range of applications. In this method, hydroxyapatite nanoparticles are synthesized using calcium sucrate and ammoniumdihydrogen orthophosphate in the presence of poly(acrylic acid). Increase in poly(acrylic acid) concentration in the synthesis medium results in the increase in the hydrodynamic radius of particle size allowing increased hydration. Poly(acylic acid) tends to control both crystallite size and colloidal stability. Increase in poly(acrylic acid) concentration decreases the crystallite size of the products but considerably increases their shelf life as stable colloidal solutions. Thermo gravimetric analysis shows that there are no combustible or volatile impurities present in these samples. This is further supported by FT-IR studies, which show three types of interactions between hydroxyapatite nanoparticles and poly(acrylic acid).

Effect of Acrylic Acid Content on Modified NypaFruticans Regenerated Cellulose Biocomposite Films

Nypafruticans (NF) is one of the agriculture crops, which grows abundantly in Malaysia. It can be used as asubstitute for commercial cellulose in order to utilize biomass waste. Regenerated cellulose (RC) biocomposite films from NF and microcrystalline cellulose (MCC) were prepared by dissolving cellulose in lithium chloride (LiCl) and N, N-dimethylacetamide (DMAc). Acrylic acid (AA) was used as surface modifier of NF. The results indicated that the addition of NF in RC biocomposite films increases the tensile strength and Young's modulus of RC biocomposite film up to 3 wt%. The elongation at break of RC biocomposite films decreased with increases of NF content. The modified NF with AA improved the tensile strength and Young's modulus but reduced the elongation at break of RC biocomposite films. The highest tensile strength and Young's modulus of RC biocomposite films was exhibited by 3% AA content.

有机硅改性聚丙烯酸酯纳米乳液的聚合稳定性研究

以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为主单体，利用不同乳液聚合工艺合成了有机硅改性聚丙烯酸酯纳米乳液，通过测定聚合过程的凝聚率及单体转化率，考察了聚合工艺、反应温度、乳化剂用量、乙烯基三乙氧基硅烷(A-151)用量、甲基丙烯酸羟基乙基酯(HEMA)用量、甲基丙烯酸(MAA)用量、pH值等因素对反应稳定性的影响。结果表明：采用半连续滴加工艺，温度在80℃~85℃，引发剂、复合乳化剂、有机硅A-151、HEMA、MAA的质量百分含量分别为0.5%、3%、4%、2%、2%时反应过程稳定性较好，凝聚物的质量百分含量低于0.5%，乳液粒径为80 nm左右，固含量40%。提高乳化剂用量有利于改善聚合反应的稳定性；升高温度、增加A-151用量不利于聚合反应过程的稳定；而搅拌速率、pH值和引发剂用量均存在使乳液聚合过程稳定的最佳值。 Organosiloxane modified acrylate nanolatex was synthesized by different emulsion polymerization processes with methylmethacrylate (MMA) and butylacrylate (BA) as main monomers. The effects of polymerization methods, reaction temperatures, amounts of initiator, emulsifier, vinyl-triethoxysilane (A151), 2-hydroxyethl methacrylate (HEMA), methyl acrylic acid (MAA) contents and pH on polymerization stability were investigated by measuring coagulation rate and monomer conversion. The results showed that with semi-continuous emulsion polymerization, organosiloxane modified acrylate nanolatex with particle size of about 80 nm and with low coagulation rate of 0.5% as well as solid content of 40 wt% was obtained under the condition of the better reaction stability when temperature at 80˚C - 85˚C, the mass fraction of initiator, emulsifier, A151, HEMA, MAA at 0.5%, 3%, 4%, 2%, 2% respectively. The increase of emulsifier contents can improve the stability of the polymerization process; but the temperature increase and the more dosage of A-151 are not conducive to the reaction stability. The optimal values for the stirring speed, pH and dosage of initiator exist for the stable state in emulsion polymerization.

Porous Poly(Acrylic Acid) from High Internal Phase Emulsion: Effects of Emulsification Parameters on Porous Structure

Highly porous poly (acrylic acid) (P(AA)) with tunable pore structure was prepared through polymerizing of acrylic acid in the aqueous phase of an oil-in-water (O/W) high internal phase emulsion (HIPE). Compared with the conventional O/W HIPE normally using toluene or hexane as internal phase, the introducing paraffin, which have a much higher viscosity than toluene or hexane, caused the HIPEs herein could be stabilized by Tween 60 of low to 0.5 wt%. It was found the amount of liquid paraffin played a key role for the stability of the emulsion and the morphology of the resulting porous materials. Moreover, the average void size and the interconnectivity degree of the porous materials could also be tailored by altering the acrylic acid and surfactant concentration in aqueous phase.

Self-assembly and the hemolysis effect of monodisperse N,N-diethylacrylamide/acrylic acid nanogels with high contents of acrylic acid.

Monodisperse temperature/pH sensitive poly(N,N-diethylacrylamide/acrylic acid) (P(DEA/AAc)) nanogels with high contents of AAc up to 40 wt% have been prepared. In this study, it was unexpectedly found that the polydispersity of the nanogels with 40 wt% AAc strongly depended on the initiator concentration. Monodisperse P(DEA/AA) nanogels were synthesized only at a very low concentration of initiator. The phase transition behavior of the nanogels in water can be tuned by pH and temperature. Due to low polydispersity, the nanogels self-assembled into colloidal crystals at different temperatures below the volume phase transition temperature (VPTT). The sharp Bragg peaks of the crystals were significantly blue-shifted as the concentration of the nanogels was increased. In contrast, the condensed suspensions without crystals still exhibited clear colours resulting from a short-range order structure. The reflection spectra of the coloured suspensions showed that the peak wavelength became a bit longer and much broader. And the reflection intensity of the coloured suspensions was much weaker. Elastic and coloured crosslinked nanogel networks prepared by a one-pot and rapid light-initiated crosslinking method showed responses to pH and temperature. Furthermore, the interaction between the nanogels and peptide melittin was investigated. The results showed that an increasing AAc composition led to more efficient inhibition of the hemolytic activity of melittin. The nanogels with 40 wt% AAc composition completely inhibited hemolytic activity at a nanogel concentration of 400 µg ml(-1). Thus, monodisperse P(DEA/AAc) nanogels of high AAc composition may be developed as efficient substitutes for antibody-based antidotes. Owing to the combined influence of the periodic structure of the crystals of the nanogels and an efficient neutralization effect, the P(DEA/AAc) nanogels show promise to become an integral step for preparing valuable naked-eye biosensors as simple, cheap and stable substitutes for antibody-based antidotes.

수분산 폴리우레탄 아크릴 접착제의 합성 및 물성 연구

In this study, waterborne polyurethane acrylate were synthesized with polyester polyol, 4,4-dicyclohexylmethane diisocyanate (), dimethylol propionic acid (DMPA), acrylate monomer to improve the properties and peel strength. In addition, the properties of the synthesized waterborne polyurethane acylate was evaluated through FT-IR, particle size analysis, UTM, peel strength. As the acrylic acid content increased, particle size increased. In the results of mechanical properties, when the acrylic acid contents increased, tensile strength was increased but elongation was decreased. All peel strength was improved as the acrylic acid contents of WPUA and acrylate ratio of PU/acrylate increased. Optimum peel strength obtained when acrylic acid was 0.5 wt%.

Microwave‐assisted polymerization: Superabsorbent polymer with improved properties

ABSTRACTMicrowave‐assisted polymerization was used as a promising technique to synthesize superabsorbent polymers. A small amount of thermal initiator was used to initiate the reaction, and the polymer's properties were evaluated at acid levels of 31–50% and degrees of neutralization of 68–75 mol %. The polymers were characterized with scanning electron microscopy, and properties such as the capacity and absorbency under a load were measured in a 0.9% sodium chloride solution. In addition, the extractable and residual acrylic acid contents were measured to determine the reaction's efficiency. In conclusion, the synthesis of the superabsorbent polymer via microwave heating reduced the time and cost of production and improved the physical properties of the polymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43325.

Effects of composition and layer thickness of a butyl acrylate/acrylic acid copolymer on the adhesion properties

Acrylic pressure-sensitive adhesives are synthesized by solution copolymerization using n-butyl acrylate and acrylic acid (AA) in ethyl acetate anhydrous. The copolymer composition is controlled for good adhesive properties by varying AA content. The monomer conversion is measured by the gravimetric method and FTIR technique. The adhesive layer thickness is measured by scanning electron microscopy, and the adhesive properties are evaluated with loop tack, 180° peel, and holding time measurements. The peel force increases with increasing the AA content up to 3 wt% and decreases at the AA content higher than 3 wt%, but the tack force decreases with increasing the AA content. The holding time increases with increasing the AA content, and it shows a similar trend with the Tg of adhesives. The increase of layer thickness improves tack and peel forces, but it weakens the holding power. A tape thickness of about 20 μm shows well-balanced properties at 3 wt% AA content in the acrylic copolymer system.

A novel kind of concrete superplasticizer based on lignite graft copolymers

A novel superplasticizer was synthesized by grafting 2-acrylamido-2-tert.butyl sulfonic acid (ATBS) and acrylic acid (AA) monomers onto a lignite backbone using free radical copolymerization technique. Different molar ratios of ATBS:acrylic acid were tested to investigate the influence of the acrylic acid content on the dispersing performance of the graft copolymer. The synthesized polymers were characterized relative to their molecular properties and their dispersing performance in cement. It was found that especially the graft copolymer with an ATBS:acrylic acid molar ratio of 1:0.15 exhibits high dispersing force, long slump retention, high sulfate tolerance and only minor cement retardation. The polymer is more effective than industrial grade BNS. Successful grafting of the monomers was confirmed by size exclusion chromatography and measurement of the adsorbed layer thicknesses.

Biogeochemistry of dimethylsulfoniopropionate, dimethylsulfide and acrylic acid in the Yellow Sea and the Bohai Sea during autumn

Environmental context Dimethylsulfide (DMS) is a climatically important biogenic trace gas that is emitted from oceans. This research focuses on the spatiotemporal distributions of DMS and its related compounds, i.e. dimethylsulfoniopropionate (DMSP) and acrylic acid (AA), and the influencing factors in the Yellow Sea and the Bohai Sea during autumn. In addition, the sea-to-air flux of DMS, kinetic responses of DMSP consumption as well as DMS and AA production are also investigated. This study is helpful in understanding the marine sulfur cycle in marginal seas in China. Abstract The biogeochemistry of dimethylsulfoniopropionate (DMSP), dimethylsulfide (DMS) and acrylic acid (AA) in the Yellow Sea (YS) and the Bohai Sea (BS) was investigated in November 2013. The concentrations (and ranges) of total DMSP (DMSPt), dissolved DMSP (DMSPd), DMS and AA in surface waters were 30.71 (1.07–122.50), 6.60 (0.85–35.67), 1.48 (0.53–5.32) and 42.2 (13.8–352.8) nmol L–1 respectively. The concentrations of DMSPd and AA were positively correlated with chlorophyll-a levels, which suggests that phytoplankton biomass has an important function in controlling DMSPd and AA distributions. Furthermore, DMS and AA concentrations revealed significant positive relationships with DMSPd concentrations. The average ratios of AA/(DMSP+AA) and DMS/AA were 53.98 and 7.62% respectively. The vertical profiles of DMSP, DMS and AA were characterised by high concentrations that mostly occur near the surface. Even under highly variable hydrographic conditions, a positive relationship was observed between DMSPt and chlorophyll-a concentrations. The rates of DMSPd consumption, as well as DMS and AA production, significantly varied with marine environments. The sea-to-air fluxes of DMS from the YS and the BS to the atmosphere were estimated to be in the range of 3.01 to 6.91μmol m–2day–1.

Synthesis of carboxymethylcellulose/acrylic acid hydrogels with superabsorbent properties by radiation-initiated crosslinking

Superabsorbent hydrogels were prepared by gamma irradiation from aqueous solutions of carboxymethylcellulose (CMC) and acrylic acid (AAc) with varying CMC:AAc ratio. By partially replacing the CMC with AAc the gelation increased and led to a higher gel fraction and lower water uptake. Moreover, the gelation required significantly milder synthesis conditions. Decreasing both the dose and the solute concentration in the presence of AAc led to gels with higher gel fraction and higher degree of swelling compared to pure CMC gels. Increasing the AAc content up to 10% proved to be very effective, while very high AAc content (over 50%) hindered the gelation process.

Permeability of pH-sensitive membranes grafted by Fenton-type reaction: An experimental and modeling study

Membrane modification by different concentrations of acrylic acid has been described. Grafting of acrylic acid to the surface of a polypropylene membrane was obtained by a Fenton-type reaction. Membrane permeability seemed to have been dependent on the value of pH in the solution. To explain tendency, a simple theoretical model was developed. The model incorporates explicitly statistical conformations of a polyacid chain grafted onto the pore surface. The charged capillary model with a varying diameter for porous membranes was then used to evaluate the permeability of the membrane. It has been shown both theoretically and experimentally that the permeability of a grafted membrane depends on the pH of the solution.

Synthesis and characterization of dual-curable epoxyacrylates for polyester cord/rubber applications

In this study, bisphenol-A-based acrylated epoxy oligomers were prepared and utilized to improve the adhesion strength of polyester cords onto rubber. The structure of the oligomers was characterized by Fourier transform infrared spectroscopy and 1H-NMR spectroscopy. Ultraviolet-curable adhesive formulations were prepared by using acrylated epoxy oligomers and applied onto the polyester cord fabric by a dip-coating method and irradiated. Ultraviolet-cured coatings were characterized by thermal and scanning electron microscope analysis, contact angle measurements. In the second stage of the experiment, ultraviolet-cured polyester cords were adhered onto rubber under heat and pressure. The prepared adhesive formulation was expected to improve the adhesion strength. The adhesion strength of the coated material was evaluated by using peel test as a function of the carboxyl/epoxide ratio. The adhesion strength of 18.0 N/cm was obtained when the carboxyl/epoxide ratio was set as 1. It was observed that peel strength, contact angle, and surface energy values of acrylated epoxies strongly depend on the acrylic acid content of the oligomer.

Effect of immobilized collagen type IV on biological properties of endothelial cells for the enhanced endothelialization of synthetic vascular graft materials

Regeneration of healthy endothelium onto vascular graft materials is imperative for prevention of intimal hyperplasia and thrombogenesis. In this study, we investigated the effect of collagen type IV (COL-IV) immobilized onto electrospun nanofibers on modulation of endothelial cell (EC) function, as a potential signal to rapid endothelialization of vascular grafts. COL-IV is assembled in basement membrane underneath intimal layer and regulates morphogenesis of blood vessels. For immobilization of COL-IV, poly(l-lactic acid) (PLLA) nanofibers (PL) were prepared as a model vascular graft substrate, onto which acrylic acid (AAc) was then grafted by using gamma-ray irradiation. AAc graft was dependent on irradiation doses and AAc concentrations, which allowed us to select the condition of 5% (v/v) AAc and 10kGy for further conjugation of COL-IV. COL-IV immobilization was proportionally controlled as a function of its concentration. Atomic force microscope (AFM) analysis qualitatively supported immobilization of COL-IV, demonstrating increase in root mean square roughness of the PL from 665.37±13.20nm to 1440.74±33.24. However, the Young’s modulus of nanofibers was retained as approximately 1MPa, regardless of surface modification. The number of ECs attached on the nanofibers with immobilized COL-IV was significantly increased by 5 times (1052±138cells/mm2) from pristine PL (234±41cells/mm2). In addition, the effect of immobilized COL-IV was profound for enhancing proliferation and up-regulation of markers implicated in rapid endothelialization. Collectively, our results suggest that COL-IV immobilized onto electrospun PLLA nanofibers may serve as a promising instructive cue used in vascular graft materials.

Role of acrylic acid in the synthesis of core‐shell fluorine‐containing polyacrylate latex with spherical and plum blossom‐like morphology

ABSTRACTThe core‐shell fluorine‐containing polyacrylate latex was successfully synthesized by two‐stage semicontinuous emulsion copolymerization of methyl methacrylate (MMA), butylacrylate (BA), acrylic acid (AA), and dodecafluoroheptyl methacrylate (DFMA). The fluorine‐containing polyacrylate latex was characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC). The effects of AA content on monomer conversion, polymerization stability, particle size, corsslinking degree, carboxyl groups distributions (latex surface, aqueous phase or buried in latex), as well as mechanical properties and water absorption rate of latex film were investigated. The obtained fluorine‐containing polyacrylate latex exhibited core‐shell structure with a particle size of 120–150 nm. The introduction of AA was beneficial for the increase of monomer conversion and the polymerization stability, and had little effects on the mechanical property of latex film. However, the hydrophilicity of AA made the water resistance of latex film get bad. With the increase of AA content, the carboxyl groups preferred to distribute on aqueous phase, and the possibility of homogeneous nucleation increased and more oligomers particles were formed. Moreover, the oligomers would distribute to the latex and continued to grow up, making the latex morphology changed from spherical to plum blossom‐like. The core‐shell latex had two Tg corresponding to the rubber polyacrylate core and hard fluorine‐containing polyacrylate shell, and the latex film possessed excellent thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42527.