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At present, controlling the workability of concrete with high clay content sand presents a significant engineering challenge. A novel phosphonate group-modified polycarboxylate superplasticizer (PHS-PCE) was synthesized by using 2-(methacryloyloxy) ethyl phosphate (MOEP), isobutyl alcohol polyoxyethylene ether (IPEG) and acrylic acid (AA). Gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FT-IR), 31P nuclear magnetic resonance (31P NMR) spectroscopy and elemental analysis measurements were conducted to characterize the molecular structure of PHS-PCE showing successful incorporation of the phosphonate group with high polymer purity. Despite the relatively low reactivity of MOEP, approximately 65 wt% monomer was incorporated into the copolymer. PHS-PCE exhibited superior flowability and stronger retardation effect than the conventional polycarboxylate superplasticizer (C-PCE), due to the increased negative charge density and enhanced complexing capacity with calcium ion imparted by the phosphonate group. In the presence of clay, the maximum variation of PHS-PCE adsorption on cement particle was 18%, whereas that of C-PCE was 25%. The phosphonate group facilitates adsorption of a portion of PHS-PCE on the clay particle edges, thereby preventing intercalation and improving the clay tolerance. [ABSTRACT FROM AUTHOR]

As temperature and salt-resistant materials, hydrophobically associating polymers can form a reversible spatial network structure through the interaction between their hydrophobic groups, effectively improve the viscosity of the polymer solution through association, and enhance the temperature and salt resistance of the polymer. Hydrophobically associating monomers have different effects on the properties of polymer solutions. Herein, acrylic acid, acrylamide, and 2-acrylamido-2-methylpropanesulfonic acid were used as hydrophilic monomers. The three hydrophobic monomers with different carbon chain lengths were prepared by the bromination reaction. Hydrophobic associating polymers DQM1-PAM, DQM2-PAM, and DQM3-PAM were prepared by aqueous solution free-radical polymerization. The structure–activity relationship of the hydrophobic monomers with different carbon chain lengths on polymers was studied. It was confirmed by Fourier-transform infrared spectroscopy and 1H-NMR that the target product was successfully synthesized. Scanning electron microscopy revealed that with increasing hydrophobic carbon chain length, the hydrophobic microarea of molecular aggregation increased, forming a closer spatial network structure. Thermogravimetric and fluorescence tests revealed that with increasing hydrophobic carbon chain length of polymer molecules, the polymerization temperature resistance increased, intermolecular association degree increased, and critical association concentration decreased. Rheological property evaluation revealed that the viscosity of 0.5% polymer DQM1-PAM, DQM2-PAM, and DQM3-PAM was 71.32, 100.21, and 118.79 mPa·s after shearing at 120 °C and 170 s−1 for 1 h. With the increase in the carbon chain length, the retention rate of shear viscosity of polymer in a salt solution increased, showing good salt resistance. Concurrently, the molecular aggregation microarea of a solution with 0.5% polymer, degree of molecular chain action, viscoelasticity of the solution (G' > G''), and thixotropic area all increased. The performance of polymer solution can be improved by modifying hydrophobically associating polymers with long carbon chains, which has a broader application. [ABSTRACT FROM AUTHOR]

Silicon (Si) -based materials have been identified as a potential alternative anode owing to their superior theoretical capacity compared to conventional graphitic carbon. Nevertheless, the huge volume change (approximately 300%) that occurs while cycling still hampers this system from 100% practical applications. Silicon-monoxide (SiOx)-based anode materials, on the other hand, are being explored extensively due to their unique properties such as high theoretical capacity, formation of Li2O and LiSiO4 during initial lithiation process that act as a natural volume buffer matrix to accommodate volume changes and formation of a stable solid electrolyte interphase layer, which improves the cyclability and capacity retention. Although poly (vinylidene fluoride) (PVdF) is widely used as a binder, the weak van der Waals forces between PVdF and silicon-based particles fail to bind particles effectively, when substantial volume change occurs. Herein, we prepare a series of SiOx-Si-C electrodes with different binders poly (acrylic acid) (PAA), carboxyl methyl cellulose (CMC) and their blends as binder. The prepared polymeric blends are subjected to thermal, morphological, mechanical and physico-chemical analyses. The Li/ SiOx-Si-C cell assembled with 100% PAA as binder delivered a discharge capacity of 1908 mAh g−1 on its first cycle and 724 mAh g−1 on its 100th cycle with a fade in capacity of 11.8 mAh g−1 per cycle. Upon the incorporation of CMC in the PAA blend the cycling performance was found to be poor. Among the various investigated compositions, the electrode with sole poly (acrylic acid) as a binder offers the highest discharge capacity and this is attributed to the high concentration of the functional (carboxylic) group which forms strong hydrogen bonds with - OH groups on the SiOx or carbon surface. The interfacial properties of the polymeric binders are thoroughly investigated by spectroscopies and electrochemical tests. [ABSTRACT FROM AUTHOR]

Undoubtedly, with the increasing awareness of the scientific community and the public, current trends are directing research to implement effective and combined yet nature friendly methodologies. Due to advantages such as adaptability and versatility, the combination of electrospinning and light is increasingly intriguing. This study proposes a new strategy for producing amphiphilic fibers from graft copolymer of polypropylene (PP) and poly (acrylic acid) (FPP-g-PAA). The first step includes the synthesis of copolymer comprising PP main chain possessing poly (tertiary butyl acrylate) pendant groups via photo-induced metal-free atom transfer radical polymerization (PIMF-ATRP) of tertiary butyl acrylate (t-BA) in the presence of perylene and chlorinated polypropylene (PP-Cl) as a macro photo-initiator (PP-g-PtBA). Then, FPP-g-PAA is prepared by acidolysis of t-BA units to acrylic acid moieties. In the second step, the PP-g-PAA is successful electrospun to fabricate the ultimate amphiphilic fibers. The chemical steps are monitored and confirmed by Fourier-transform infrared (FT-IR) and proton magnetic resonance (1H-NMR) spectroscopies, and gel permeation chromatography (GPC). Following the structural characterization, morphological and wetting properties are systematically determined with scanning electron microscopy (SEM) and water contact angle (WCA) measurement by depending on surface characteristics of the samples. Thermal behaviour of precursors and synthesized electrospun fibers has also been evaluated and compared by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The SEM images display that the achieved fibers were smooth and circular with the average diameters ranging from 3.3 μm up to 3.9 μm. After WCA measurements, it was elucidated that the hydrophobic nature of electrospun PP-g-PtBA was transformed into amphiphilic structure by hydrolysis of PtBA pendant groups. The reported approach is very encouraging and expected to trigger further development for scientists preparing various types of amphiphilic polyolefin fiber based materials. [ABSTRACT FROM AUTHOR]

Selective recognition of metal ions is a real challenge for a large range of applications especially in sorption purposes. The use of ultrasound in the synthesizing and modifying of sodium alginate-based material is investigated, for enhancing the dispersion, degassing, crosslinking processes and enhance the homogeneity of ion imprinted polymer properties. Cobalt imprinted polymer was prepared using an inexpensive and simple ultrasonic-mediated polymerization process that incorporated dual functional monomers, acrylic acid, and 2-Acrylamido-2-methylpropane sulfonic acid to feature a multifunctional of carboxylic and sulfonic groups. SEM, TGA, DTA, and EDX were used to analyze the surface morphology. FT-IR study confirmed that the complexation of the Co-IIP was successfully takes place. The ability of the adsorption of ion imprinted was optimized at pH 5. The increase of the temperature from 27 to 52 °C caused the increase in the adsorption capacity. Batch tests have been performed to evaluate the selectivity mechanism, and found that the prepared polymer exhibit excellent selectivity for Cobalt, more than nickel, and strontium at 300°K (single component) were 71, 20, and 12 mg.g−1 respectively. Pseudo-second-order kinetics and the Langmuir isotherm gave the most satisfactory explanation for the adsorption process. The prepared polymer can be reused 5 times with a very low loss in adsorption capacity. The prepared ion imprinted polymer is efficiently utilized in controlling Co2+ sorption/desorption processes, enabling its successful recovery from complex sample matrices for various applications especially that required separation processes. [ABSTRACT FROM AUTHOR]

Improving water-based polymer's properties using silicon compounds is strongly noticed nowadays. A novel siloxane-based crosslink agent was synthesized using oligomeric polydimethylsiloxane (PDMS) hydroxyl-terminated. The crosslinker was used for emulsion copolymerization of methyl methacrylate (MMA), butyl acrylate (BA), and acrylic acid (AA). Incorporation of the crosslinker in the structure of the copolymer increased the average latex particle size (from about 165 to 207 nm) and as a result, the viscosity of the latexes was dramatically decreased (from 212 cP to 83 cP). The crosslink density of the latexes, meanwhile, was raised (from about 7–60%). Electrostatic stability of the latexes was improved in the presence of the crosslinker (zeta potential from − 31.7 mV to -49.5 mV and the average mobility of the latexes particles from − 2.4 μm/s/V/cm to -3.8 μm/s/V/cm). The crosslinking agent affected both the initial decomposition temperature and residual weight fraction of the copolymer (from 353 to 406 °C and from about 0.5 w% to 12.4 w% respectively). A morphological study of the latexes was carried out using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. The addition of the crosslinker, led to a decrease in the contact angle (from 70 to 39 degrees) of the latexes film formed. [ABSTRACT FROM AUTHOR]

The increasing worldwide waste of polymers and agricultural products has prompted a pressing need for biodegradable plastic to help protect the environment. Hence, this research focuses on polybutylene adipate-co-terephthalate (PBAT) biodegradable polymers containing between 30–50 percent of filler to achieve an optimal balance of mechanical properties and biodegradation. Given its high lignin content, rice husk (RH) has displayed comparable properties to those of commercial lignin, and thus, the lignin from the rice husk was modified with acrylic acid grafting to facilitate the composite fabrication process. Fourier transform infrared (FTIR) analysis was used to demonstrate the grafting synergy and verify that the lignin/rice husk had been successfully grafted with the acrylic acid grafting process. Subsequently, the acrylic acid grafted lignin/rice husk was incorporated into PBAT to create a PBAT composite containing 30–50% AA lignin. The results revealed that the lignin: PBAT ratio at 30:70 (P70L30) resulted in the most optimum mechanical properties and biodegradability. These included tensile strength of 19.48 MPa, elongation at break of 20.26 MPa, Young's modulus of 1913.62%, and crystallinity of 31.45%. The biodegradation of P70L30 was 57.36% over the 6 months, which was faster than the 9.2% degradation of PBAT. Additionally, the water absorption of P70L30 was two times more compared to PBAT, indicating the change in hydrophobicity of PBAT to a hydrophilic composite. Agricultural waste-rice husk displayed identical properties to lignin when incorporated into PBAT and resulting in the mechanical properties of strength, elongation at yield, and Young's modulus of 19.09 MPa, 21.87%, and 1936.98 MPa. The mechanical properties and biodegradability of P70L30 on both lignin/rice husk in PBAT composite demonstrated the potential of affordable materials to create sustainable packaging solutions with good biodegradability and added features. [ABSTRACT FROM AUTHOR]

In the study, the loading and desorption properties of four different drug models, namely ibuprofen sodium (IBFNa), diclofenac sodium (DCFNa), gentamicin sulfate (GS), and propranolol hydrochloride (P-HCl), through chitosan (CHI)/poly(acrylic acid) (PAA) and poly(styrene sulfonate) (PSS) based multilayers are monitored using quartz crystal microbalance-dissipation (QCM-D) and UV–vis spectrophotometry. Also, the layer growth of single/blend layer-by-layer (LbL) films is studied as a function of the blend composition. 72.5% DCFNa, 37.5% IBFNa, 34.7% GS, and 23.3% P-HCl (w/w) loadings are achieved for the LbL multilayers. Drug-loaded LbL films start to lose their layer integrity under an acidic medium regardless of the drug type while they show large swelling at pH 11. ΔD values significantly increase with IBF-Na and DCF-Na loading whereas this effect is minimal for GS and P-HCl insertion. In vitro analyses reveal that most of the loaded drug is released within five minutes and the desorption percentages are found to be 20.7% and 20.6% at pH 6.8 and 11 at the end of 120 h, respectively. SEM results show that the LbL films partially shrink and become more rugged during IBF uptake and release. The main findings of this study can provide a basis for controlling the loading and release of the desired drug molecule depending on the multilayer composition and stability as a function of the swelling properties and polyelectrolyte-drugs interactions. [ABSTRACT FROM AUTHOR]

Terbutylazine (TER)—simetryn (SIE) molecularly imprinted polymers (TER-SIE-MIPs) were prepared by precipitation polymerization with TER and SIE as double template molecules, acrylic acid (AA) as the functional monomer, and acetonitrile as the porogen. A method of molecularly imprinted solid-phase extraction combined with high performance liquid chromatography (MISPE-HPLC) was developed for the determination of four triazine herbicide residues in tobacco leaves. The optimal functional monomer was firstly selected, then the optimal binding ratio between template and monomer was determined by computer simulation algorithm. The adsorption performance of the MIPs to double template molecules was investigated by adsorption experiments. It was found that the MIPs had two types of affinity sites, and good specific adsorption capacity for TER and SIE and their structural analogs. Then TER-SIE-MIPs was used as a solid phase extraction filler to prepare a TER-SIE-MISPE column for pretreatment of spiked tobacco leaves, and the pretreatment liquid was analyzed by HPLC, and the results showed that TER-SIE-MISPE had better enrichment effect on terbutylazine, simetryn, terbumeton and prometryn. The average recoveries of the four triazine herbicides were between 80.95 and 103.15%, and the relative standard deviations (RSD) were 1.82 ~ 2.57% (n = 3), the method can meet the requirements of simultaneous determination of terbutylazine, simetryn, terbumeton and prometryn triazine herbicide residues in tobacco leaves. [ABSTRACT FROM AUTHOR]

To improve the weatherability and antibacterial property of acrylic emulsion, a new kind of acrylic emulsion with UV-shielding and antibacterial properties was prepared by soap-free emulsion polymerization with (3-acrylamidopropyl)trimethyl ammonium chloride (ATAC) and 2- [3-(2H-Benzotriazol-2-yl)-4-hydroxyphenyl] ethyl methacrylate (BHEM) as functional monomers. A series of testing methods, including transmission electron microscopy (TEM), zeta potential, dynamic light scattering (DLS), gel permeation chromatography (GPC), Fourier transform infrared spectrum (FT-IR), ultraviolet absorption spectrum (UV), X-ray photoelectron spectroscopy (XPS), artificial accelerated aging test and antibacterial test, were adopted to characterize the emulsion and its coating. Results based on the characterization indicated that the particle size and zeta potential of the emulsion were 82.68 nm and 26.5 mv respectively, and its polydispersity index (PDI) was 1.4076. The emulsion was modified by the functional monomers and endowed it with good antibacterial property and strong UV-shielding performance at 295 nm and 340 nm. After 240 h aging test, the color difference (ΔE) and rate of loss of gloss (ΔG) of the coating made by the new emulsion were only 2.81 and 5.12% respectively, which were much lower than 16.85 and 52.43% of the unmodified coating. The antibacterial test showed that only a few colonies appeared on the surface of the medium coated with the new emulsion after 24 h incubation, while dozens of colonies were appeared in the control groups. [ABSTRACT FROM AUTHOR]

Polystyrene latexes where the stabilizing moiety originated from I) the inistab (initiator + stabilizer), 4,4'- Azobis(4-cyanopentanoic acid) (ACPA), II) acrylic acid (AA) (in situ copolymerized) or/and III) previously synthesized poly(acrylic acid)-block-polystyrene (PAA-b-PS) were prepared via surfactant-free emulsion polymerization (SFEP). This attitude of incorporating the sodium carboxilate groups (COO−Na+) as negatively charged stabilizing moieties in different materials yield quite different nucleation mechanism. Therefore, the different particle size would be expected. The average size of latex particles were ranged from 1.3 micron to 50 nm. Using ACPA as the only stabilizer produced latexes that were ranged from 200 nm to 1.3 micron. In contrast, when the stabilizing moieties originated from PAA-b-PS, the latexes exhibited the size below the 100 nm. By combining the use of both in situ polymerized ACPA inistab, AA monomer with/without PAA-b-PS, we were able to produce latexes with tunable polystyrene particle sizes. [ABSTRACT FROM AUTHOR]

To effectively control CaCO3 scaling in oilfield-produced water, terpolymer scale inhibitor P(IA-AA-SHP) was synthesized by aqueous solution polymerization using itaconic acid (IA), acrylic acid (AA) and sodium hypophosphite (SHP) as raw materials and ammonium persulfate as an initiator. The optimal monomer ratio, initiator dosage, reaction temperature, and time for copolymer synthesis were determined by the controlled variable method. According to the static scale inhibition performance test method in the oilfield, the copolymer dose reached 95.8% inhibition efficiency of CaCO3 at 30 mg L−1. A study of the inhibitory efficiency of copolymer on the CaCO3 scale at different Ca2+ concentrations, CO32− concentrations, and temperatures was also carried out, and the excellent scale inhibition efficiency was maintained despite a change in the water quality conditions. The structure of copolymer P(IA-AA-SHP) was characterized by FTIR, UV, 1H-NMR, and 13C-NMR. Since the molecular weight (Mw) has a great influence on the scale inhibition performance, the relationship between the molecular weight of the polymer and the scale inhibition performance was discussed using gel permeation chromatography (GPC) to detect the molecular weight of the product. The copolymers were shown to have excellent thermal stability using thermogravimetric (TGA) analysis. The effect of copolymers on the morphological structure of CaCO3 crystals was analyzed by SEM and XRD, and the mechanism of scale inhibition was discussed. [ABSTRACT FROM AUTHOR]

In this study, a multifunction polymeric adhesion promoter and anti-aging compound based on the triethanolamine salt of acrylamide acrylic acid copolymer (COS) was prepared and characterized using Fourier-transform infrared spectroscopy (FTIR). The impact of different COS contents on the tensile, adhesion, and thermal properties of NBR composite and NBR/PET sandwich was evaluated. The NBR composites containing COS displayed good retention of their mechanical properties with increasing thermal ageing time, while the composite without COS showed a decrease in its mechanical properties. The highest tensile strength (17.5 MPa with a retention value of 0.6%) after 7 days of thermal aging was recorded for NBR composite, which contains 5 phr (parts per hundred parts of rubber) of COS (COS 5), compared to NBR composite without COS (COS 0), which recorded 15.1 MPa with a retention value of -27.4%. In addition, the COS 5 composite displayed an improvement in peel strength of 16.4% compared to the COS 0. The results of the thermogarvemetric analysis (TGA) supported the anti-thermal ageing effect of COS, where the initial decomposition temperature (Ti) value increased by 11.7 and 9.3 °C, after addition of 5 and 10 phr of COS to NBR composite, respectively. In addition, the other thermogravemetric parameters investigated displayed a significant increase in their values, which confirms the improvement in thermal stability of NBR composite in the presence of COS. Also, the air permeability of the PET/NBR sandwich decreased by 80% after the addition of 7.5 phr of COS. [ABSTRACT FROM AUTHOR]

In the investigation, the allyl methacrylate-based copolymer emulsion was synthesized via semi-continuous seeded emulsion polymerization utilizing Aloe-Vera and allyl methacrylate/butyl acrylate/methyl methacrylate and acrylic acid as monomers. Various characterization techniques such as SEM, FTIR, XRD, TGA, DTA, DSC, 1H and 13C NMR spectroscopy were used for the determination of surface morphological and characteristic properties of the prepared nanoemulsion. Some properties of prepared nanoemulsion such as solid content, tensile strength, % elongation, water resistance, freezing–thawing stability, alkali resistance and electrolytic stability were determined comprehensively. The obtained results showed tremendous improvement in the physical properties of nanoemulsion with a 70:30 ratio of the organic phase and water phase as well as showed the outstanding antimicrobial performance against two (G +) bacteria: MTCC442 & MTCC1144 and one (G–) bacteria: MTCC2474. [ABSTRACT FROM AUTHOR]

Our scope is synthesis a new poly fluorobenzamide oxime ester and study its structural, optical, and dielectric properties. Consequently, ((E)-2-((acryloyloxy)imino)-N-(4-fluorophenyl) acetamide) (AIFPA) was as-synthesized via a condensation reaction of (E)-N-(4-fluorophenyl)-2-(hydroxyimino) acetamide with acrylic acid to polymerize it via free radical polymerization (PAIFPA). over and above, the synthesized PAIFPA was inserted in more polymerization action with polystyrene sulfonate through the grafting process (PAIFPA-co-PSS). The chemical structures and morphology of AIFPA, PAIFPA, and PAIFPA-co-PSS were characterized by 1H NMR, FTIR, and XRD. The crystallinity index of PAIFPA, and PAIFPA-co-PSS was studied, affording that PAIFPA-co-PSS has the highest crystallinity. Moreover, The optical bandgap that obtained from absorbance analysis was encountered to be in the range of 2.6 eV to 3.5 eV. Ultimately, the dielectric properties of PAIFPA, and PAIFPA-co-PSS showed that electric conductivity values ranged from 6.12 × 10–8 to 7.11 × 10–7 S.cm−1, and 5.48 × 10–10 to 7.75 × 10–8 S.cm−1, respectively. It has a great deal of interest of PAIFPA-co-PSS which has wide band gap energy as short-wavelength light absorbers to be used in tandem polymer solar cells. [ABSTRACT FROM AUTHOR]

A series of superabsorbent polymers (SAPs) were synthesized free-radically using hydroxyethyl methacrylate (HEMA), acrylic acid (AA) and its potassium salt, methacrylic acid (MAA) and its potassium salt as monomers, and N,N'-Methylenebisacrylamide (N,N1-MBA) as crosslinker. The synthesized SAPs were evaluated for their chemical structure (FT-IR), thermal stability (TGA/DTG), surface morphology (SEM), and water, fertilizers uptake and release characteristics (swelling and deswelling). A SAP with the optimized composition of monomer and crosslinker had absorbed 898 g/g of water, and 68% of urea and 51% of potash from the 1% corresponding fertilizer solutions. The equilibrium swollen SAP had released the absorbed water completely over 21 days, but only 28% of potash and 43% of urea were released from the fertilizer-loaded SAPs under identical conditions with the same duration of release time. The water uptake followed Fickian diffusion mechanism for the optimized SAP. Thus obtained experimental results revealed that the synthesized SAP may be used as the matrix for the controlled release of water and fertilizers in the agricultural sector. [ABSTRACT FROM AUTHOR]

A series of polyacrylate latex films with core–shell particle structure and different damping properties were first prepared by seed emulsion polymerization and by adjusting the ratio of soft/hard monomer in the core and shell layers of the latex particles. Higher damping factor (tan δ) was obtained by using styrene that has a bulky side group instead of methyl methacrylate as the hard monomer, and the homogeneous distribution of styrene was critical for improving its damping performance. Epoxy resin/polyacrylate composite latex materials were then prepared based on this pure polyacrylate latex. Pure polyacrylate or epoxy resin/polyacrylate composite latex material with larger tan δ was obtained when acrylic acid or epoxy resin was located in both the core and the shell layers of the latex particles simultaneously, rather than in the core or shell layer only. With increasing content of epoxy resin, the tan δ of the composite latex increased slightly, and the tan δ area (TA) increased significantly, the tan δ peak temperature gradually shifted to lower temperature, and the effective damping temperature range gradually expanded. [ABSTRACT FROM AUTHOR]

An interpenetrating polymer network (IPN) containing gum acacia (GA), poly(methacrylic acid) (MAA), and poly(acrylic acid) (AA) was developed using a two-step aqueous polymerization method. Firstly, semi-IPNs were produced by radical polymerization of MAA chains onto GA in the presence of ammonium persulfate as a free radical initiator and N, N′-methylene-bisacrylamide (MBA) as a cross-linking agent using a microwave heating. To obtain a semi-IPN with a higher swelling percentage, several reaction parameters such as initiator, monomer, and crosslinker concentrations were varied. The percentage swelling (%S) was highly dependent upon the reaction conditions. The optimal reaction conditions for maximal %S were 2.55 × 10–2 mol/L initiator concentration, 12 mL solvent, 0.424 × 10–3 mol/L of monomer, and 2.16 × 10–2 mol/L cross-linker concentration, according to the findings. GA-g-poly(MAA) was the name to given to the semi-IPN. Second, IPN was created by grafting AA chains onto a GA-g-poly(MAA) matrix that had been optimized. The IPN was named as a GA-g-poly(MAA-IPN-AA). The reduction of silver ions to silver nanoparticles (AgNPs) was carried out by heating the mixture of flower extract of Koelreuteria apiculate under microwave radiation. Finally, the as-prepared semi-IPN and IPN samples were used as templates for the loading of AgNPs. XRD, FTIR, SEM, and TGA were used to characterize the synthesized semi-IPN, IPN, and their composites with AgNPs. GA, GA-g-poly(MAA), GA-g-poly(MAA-IPN-AA), and their composites with AgNPs are tested for antibacterial activity against five common bacteria strains: Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Rhizobium species, and Staphylococcus aureus. All of the bacteria strains were shown to have a noticeable zone of inhibition when IPN and their composite with AgNPs were used. When compared to other bacteria strains, Pseudomonas aeruginosa was observed to be more vulnerable to the tested samples. The obtained results demonstrate that the synthesized systems are suitable for application as antibacterial agents. [ABSTRACT FROM AUTHOR]

In this study, we prepared graphene oxide-based styrene/acrylic elastomeric disks (GSAE) from sugarcane bagasse/ferrocene (GO) and styrene/acrylic emulsion (SAE) to apply as new adsorbents for Ni(II) from aqueous media. The adsorption activity of Ni(II) from aqueous environments by the prepared elastomeric disks was investigated against time, temperature, and concentration of adsorbate in a batch system. Environmentally-friendly graphene oxide (GO) was successfully synthesized in a single step starting from sugarcane bagasse via oxidation in the presence of ferrocene under muffled atmospheric conditions. SAE copolymers were then grafted with the generated GO nanosheets at different weight ratios of (SAE: GO) 0:1, 0.25:1, 0.5:1, 0.75:1 and 1:1 to produce the corresponding GSAE elastomeric disks represented. The synthesized adsorbents were studied using various analytical techniques. Those technical methods proved that the thermal stability, crystallinity, and mean hydrogen bond strength (MHBS) of the prepared GSAE elastomers decreased, and porosity increased upon increasing the total content value of SAE. The highest removal percentages of Ni(II) were accomplished at 98.48 and 96.62% for weight ratios 0.5:1, 0.75:1, respectively for 15 min at 318 K. [ABSTRACT FROM AUTHOR]

A semi interpenetrating polymer network (SIPN) of Aloe-vera-poly(acrylic acid) and its nano-composite were synthesized by free radical polymerisation method. Effect of various chemical properties on percentage swelling of nano-composites was investigated. Nanoparticles in SIPN was characterised by FTIR, Field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA) and electron dispersive spectroscopy (EDS). Synthesized nanocomposite was evaluated as an adsorbent for the adsorption of carcinogenic dye malachite green. Optimised condition for removal of malachite green dye from synthesized nanocomposite was pH 10, time 16 h, dye concentration 10 ppm and adsorbent dosage 0.05g. Maximum dye removal exhibited by the synthesized nano composite was 98.2%. Dye adsorption isotherm and kinetics were best explained through Freundlich adsorption isotherm and pseudo second order model, exhibiting its correlation coefficient (R2)0.99569 and 0.99271. Thus, synthesized nano-composite was utilised as an efficient device for dye sorption. [ABSTRACT FROM AUTHOR]

Several interpenetrating network (IPN) type hydrogels were made by free radical crosslink copolymerization of acrylic acid (AA) in an aqueous solution of guar gum (GG). N'N-methylene bis acrylamide (MBA) was used as a crosslinker. The hydrogels were prepared by varying the synthesis variables such as concentration of the initiator, crosslinker, AA monomer and GG polymer in water. These hydrogels were characterized by FTIR, 13CNMR, SEM, XRD DTA-TGA and mechanical properties. The effect of the synthesis variables, solution pH, and the salts present in water on the swelling, diffusion and the network parameters of the hydrogels were studied. The release kinetics of a model drug pyridoxine hydrochloride (vitamin B6) was studied with these semi-IPN type polymers. The release rate of pyridoxine from the polymer at a solution pH of 7.5 was faster than its release rate at a pH of 1.5 due to its shrinkage at this low pH. The IPN prepared with 1wt% initiator, 1wt% crosslinker, 25 wt.% AA in water and 4 wt.% GG showed a high entrapment efficiency of 94% and a sustained release rate of 95% for pyridoxine drug in 30 h. The drug release data showed a close fitting to the Korsmeyer–Peppas model. [ABSTRACT FROM AUTHOR]

Effective non-covalent molecular imprinting on a polymer depends on the extent of non-bonded interactions between the template and other molecules before polymerization. Here, we first determine functional monomers that can yield a doxycycline-imprinted hydrogel based on the hydrogen bond interactions at the prepolymerization step, revealed by molecular dynamics (MD) simulations, molecular docking, and simulated annealing methods. Then, acrylic acid (AA)-based doxycycline (DOX) imprinted (MIP) and non-imprinted (NIP) hydrogels are synthesized in cross-linker ethylene glycol dimethacrylate (EGDMA) ratios of 1.0, 1.5, 2.0, and 3.0 mol%. Here, molecularly imprinted polymer with 3.0 mol% EGDMA has the highest imprinting factor (1.58) and best controlled drug release performance. At this point, full-atom MD simulations of DOX–AA solutions at different EGDMA concentrations reveal that AA and EGDMA compete to interact with DOX. However, at 3.0 mol% EGDMA, AA attains numerous stable hydrogen bond interactions with the drug. This study demonstrates that the concentration of the cross-linker and functional monomer can be adjusted to increase the success of imprinting, where the interplay between these two parameters can be successfully revealed by MD simulations. [ABSTRACT FROM AUTHOR]

This article dwells on the issues of investigating 1-cyano-1-methylethylmethyl(4-pyridinyl)dithiocarbamate in reversible addition-fragmentation chain transfer (RAFT) polymerization of wide range of monomers (acrylic and methacrylic acid, isobornyl acrylate, styrene, tert-butyl acrylate, 2,2,3,3,4,4,5,5-octafluoropentyl acrylate, vinyl acetate, N-vinylpyrrolidone, n-butyl methacrylate, tert-butyl methacrylate, methyl methacrylate). As an "pH-switchable" RAFT agent, 1-cyano-1-methylethylmethyl(4-pyridinyl)dithiocarbamate (CMPC) can be applied in polymerization both more activated monomers (MAMs), and less activated monomers (LAMs). 4-toluenesulfonic acid monohydrate (p-TSOH), trifluoromethanesulfonic acid (TFOH), and trifluoroacetic acid (CF3COOH) were used to moderate activity of the RAFT agent. CMPC provides good control over polymerization of LAMs (vinyl acetate, N-vinylpyrrolidone). Addition of one equivalent of a protic acid makes CMPC more effective in controlling polymerization of some MAMs. The good control was achieved also in polymerization of styrene, acrylic acid, methacrylic acid, 2,2,3,3,4,4,5,5-octafluoropentyl acrylate monomers, and slightly worse in the case of isobornyl acrylate and tert-butyl acrylate. The poor control was shown for n-butyl methacrylate, tert-butyl methacrylate, methyl methacrylate. Besides, polyLAM-block-polyMAM (for instance, PVAc-b-PtBMA) with narrow molecular weight distributions was obtained. [ABSTRACT FROM AUTHOR]

Structural combining of polymer hydrogel network with mineral nanoparticles (metals, oxides, salts) is a very promising approach to create new functional materials with the specific properties. In this study, the cross-linked polymer hydrogels with embedded cadmium sulphide nanocrystals have been synthesized via radical copolymerization of acryl amide with acrylic acid or 2-(dimethylamino)ethyl methacrylate and N,N′-methylenebis(acrylamide) as cross-linker in aqueous media in the presence of nanoparticle precursor—cadmium salt, followed by subjecting the hydrogel obtained to gaseous hydrogen sulphide; this provides the in situ formation of CdS nanocrystals in pores of the hydrogel polymeric network. The effect of the Cd2+ cation concentration on the copolymerization kinetics, as well as on the gel-fraction content has been studied. The formation of CdS nanocrystals with the size of 3–6 nm has been proved by UV–vis spectroscopy and X-Ray diffractometry. Importantly, the nanocrystal size is largely determined by the density of the hydrogel polymer network. The compressive strain of hydrogels with CdS nanoparticles is significantly larger than that for the initial hydrogels containing Cd2+ cations only, apparently owing to the breaking of ionic and coordination bonds between metal cations and polar functional groups of matrix copolymer, which provide additional cross-linking of the hydrogel matrix. The obtained nanocomposite hydrogels are highly elastic materials characterized by a sufficiently high strength. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the synthesis, characterization, and adsorptive properties of composite hydrogels that can be used to remove MB dye from aqueous solutions. Composite hydrogels were used to remove the MB from aqueous solutions. Composite hydrogels were synthesized by free radical polymerization of 2-acrylo-amido-2 methyl propane sulfonic acid (AMPS) and neutralized acrylic acid (70%-AA) as monomers in the presence of laponite clay (LAP). The composite hydrogels were characterized by FTIR, SEM and XRD. In composite hydrogels, the effect of monomer ratio and clay content on swelling and adsorption properties were also investigated. In the swelling behavior of composite hydrogels, it was determined that laponite acted as a crosslinker but was not sufficient alone. For this reason, chemical crosslinker was also utilized with laponite for increasing the stability and strength of the composite hydrogel. In the adsorption study for MB adsorption, it was observed that the adsorption capacities of the synthesized composite hydrogel were slightly lower or almost equal to those of the pure hydrogel. The capacities of composite hydrogels ranged from 900–1385 mg / g. It was determined that the higher the amount of AMPS present in the composite hydrogel the higher the amount of dye removed from the concentrated matrix medium of synthetic sea water at 1000 ppm MB. In addition, it was observed that increasing the amount of LAP resulted in some reduction in the adsorption time relative to pure hydrogel. This makes the hydrogel to be easily applicable in adsorption studies. [ABSTRACT FROM AUTHOR]

Stimuli-responsive controlled release system is an effective way to increase the efficiency of agrochemicals and reduce environmental pollution. In this work, a novel polypyrrole@gelatin/poly (acrylic acid) (PPy@Gel/PAAx) hydrogel with a semi-interpenetrating network structure was synthesized by gelatin, polypyrrole (PPy) and acrylic acid (AA). The structure and property of the hydrogel were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, ultraviolet–visible spectroscopy and infrared imaging. The efficiency of the controlled release system was systematically studied by using carbendazim as a template drug. The results indicated that PPy@Gel/PAAx not only has outstanding light-sensitive property, but also has good water retention performance. Therein, PPy used as a light-sensitive component, could convert the absorbed light energy into heat energy. This kind of photothermal conversion could lead to helix-coil structural transition of gelatin which promotes the release of carbendazim by changing the pore diameter of the hydrogel. Consequently, excellent controlled-release capacity and water retention performance enable PPy@Gel/PAAx hydrogel to be a potential candidate in agricultural application. [ABSTRACT FROM AUTHOR]

hydrogels were synthesized by free radical polymerization of Acrylic acid (AAc) and 3-sulfopropyl acrylate potassium salt (KSPA) in aqueous solution using N,N'-methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as initiator. This were designated as copolymer KSPAC. Water swelling studies of copolymer hydrogels with different mol and initiater percent were performed. The hydrogel showing the highest swelling percent in water has been modified using Acrloyl GuarGum (AGG). hydrogel with three different weight percent of AGG were synthesized, designated as AGGKSPAC1,2,3 respectively. AGGKSPAC2 was found to show much higher ES% than the AGGKSPAC1 & AGGKSPAC3. These hydrogels have been employed as carriers and in vitro releasing materials for Gentamicin drug. Drug loaded and unloaded hydrogels were characterized from FTIR, 13C NMR, DTA, TGA SEM, XRD BET. At different pH the absorption and release of drugs were studied. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA)/corn stover (CS) composites were prepared by melt blending different proportions of PLA and added CS. PLA was grafted with acrylic acid to improve the compatibility of the matrix with CS. PLA-g-AA interacted well with CS, resulting in a denser composite material with relatively satisfactory hydrophobic properties. The barrier and mechanical properties of composites were studied, and it was found that the barrier and mechanical properties of PLA-g-AA/CS composite materials were significantly improved, especially those with 30 wt% CS provided better tensile properties and elongation at break. The structure at the tensile section of the composite material was observed using SEM. The proper amount of CS had better dispersion in the matrix, and PLA-g-AA could further improve the interfacial bonding force. The crystallization and thermal properties of the composites were analyzed using XRD, DSC, and TGA, and the effect of the CS content on the crystallinity of composites was also studied. [ABSTRACT FROM AUTHOR]

Nanocomposites and silver nanocomposite coatings based on a copolymer of 1-vinyl-1,2,4-triazole and acrylic acid were synthesized in an aqueous and aqueous-ethanol medium on pure iron and steel electrodes by the electrochemical method. The composition and structure of nanocomposites is confirmed by UV, IR spectroscopy, X-ray diffraction analysis, transmission electron microscopy, thermogravimetric method, etc. It was found that the solubility of nanocomposites depends on the concentration of silver particles in the (co) polymer matrix. Stage by stage thermal decomposition of nanocomposites takes place. [ABSTRACT FROM AUTHOR]

Natural joints have the hierarchical structure of bone and cartilage, providing excellent lubrication and load-carrying capacity. In our research, the hierarchical structure artificial joints of Poly Acrylic Acid (PAA)- Poly Acrylamide (PAAm) hydrogel coating and Ti6Al4V substrate were formed using a simple yet versatile method by mimicking the hierarchical structure of natural joints. The efficient lubrication at friction interfaces was achieved. The composition and microstructure were confirmed by Fourier-transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM). The hydrogel coatings were successfully prepared on the surface of Ti6Al4V substrate through the adsorption of the charged group. This hierarchical structure material exhibits the lower dynamic friction, approximately 0.085, which is much lower than bare Ti6Al4V, about 0.429. The wear on the surfaces after the tribological experiment is super-shallow and has no significant fracture area around the scratch. The PAA-PAAm hydrogel has a more uniform and compact cross-linked network porous structure, and the porous size is much smaller than PAA hydrogel. The cross-linked network porous structure is the main factor accounting for the low dynamic friction. This hierarchical structure of soft and hard improve the load-carrying ability and has the potential uses in artificial joints. [ABSTRACT FROM AUTHOR]

The inorganic-organic hybrid coatings based on UV curable urethane acrylate contained two types of polyhedral oligomeric silsesquioxane (POSS) were prepared. The hydroxyl functionalized POSS nanoparticles, pristine POSS, and the one modified by acrylic acid utilized to study the effect of nanoparticle content and its functionality on ultimate mechanical properties of the hybrid coatings. The nanomechanical properties and scratch resistance of nanocomposite coatings were evaluated with nanoindentation and nanoscratch techniques, respectively. Consequently, the results compared with previously obtained DMTA data. The results revealed that by embedding acrylic acid modified POSS, the surface hardness and elastic modulus improved. Further increasing acrylic acid modified POSS content to 5%, the surface elastic modulus and hardness improved to 37% and 35%, respectively, relative to neat coating and also the enhanced scratch resistance was observed. Furthermore, the discrepancy between the surface elastic modulus and bulk elastic modulus was rationalized and the contributed parameters that led to this deviation such as pile-up area, holding time and hydrostatic stress was investigated. The results showed that apart from the inefficiency of Oliver and Pharr method to precisely evaluate the nanomechanical properties of hybrid coatings, the targeted placement of POSS nanoparticle is responsible for this disparity between surface mechanical properties and its bulk values. [ABSTRACT FROM AUTHOR]

In this research, we presented the synthesis of cross-linking poly N-vinyl pyrrolidone /acrylic acid hydrogel and nanoclay hydrogel based on gelatin which named gelatin-g-NVP-AA, gelatin-g-NVP-AA/MMT and used them as cephalexin drug delivery. These hydrogels were fully characterized by FTIR, SEM, TEM, XRD, TGA, DSC, Also, the effect of difference saline solution, temperature, the percentage of nanoclay and time were investigated. In addition, because of pH sensitivity of hydrogels, the swelling, drug loading and drug releasing were studied in different pHs, distilled water and buffers to determine the best condition for each situation which resulted illustrated the universal buffer in pH 8 was the least interaction with hydrogels and had maximum drug loading and releasing in this condition. Antibacterial activities of hydrogels were examined against the S. aureus and the E. coli and showed an interesting result for the loaded drug on gelatin-g-NVP-AA/MMT. [ABSTRACT FROM AUTHOR]

Aimed to removal of toxic dyes and heavy metal ions, the magnetic Fe3O4-based starch- poly (acrylic acid) nanocomposite hydrogel (Fe3O4@St-AcANCH) is designed and synthesized using free radical method. The main procedure for the synthesis of superabsorbent nanocomposite hydrogel is chemical crosslinking of starch and poly (acrylic acid). The as-prepared nanocomposite hydrogel present high removal percentage toward Cu(II), Pb (II), MV and CR solution through a spontaneous physic-sorption process that have a good consistence with pseudo-second-order and Langmuir isotherm models. It is indicated that nanocomposite hydrogel is an effective adsorbent for removal of dyes and metal ions which would provide a new platform for water and environmental considerations. Finally, the swelling properties and mechanical parameters of the prepared adsorbents were investigated preliminarily. [ABSTRACT FROM AUTHOR]

Coco peat-grafted-poly(acrylic acid)/NPK [CP-g-P(AAc)/NPK] slow release fertilizer hydrogel (SRFH) was prepared by grafting coco peat fiber onto acrylic acid in the presence of NPK 15–15-15 fertilizer using in-situ solution polymerization technique. Commercial super absorbance polymer (CSAP) was used to compare the properties of SRFH. The hydrogels were characterized by fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and ultraviolet-visible spectroscopy (UV-Vis). The grafting reaction is approved by the disappearance of peak at 973 cm−1 of FTIR spectrum. DSC results revealed that SRFH had high glass transition temperature, Tg compared to CSAP. SEM images showed that SRFH had low porosity and compact structure than CSAP. Fertilizer release study showed that the amount of nutrient release is greatly improved by SRFH. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) hybridized poly(N-isopropylacrylamide)-co-acrylic acid (PNIPAM-co-AAc) hydrogel on thermoplastic polyurethane (TPU) were successfully prepared via photocatalytic polymerization technique. Low temperature plasma processing of HMDSZ and O plasma were deposition on substrate. The HA/hydrogel were stabilized by HA of which the wettability was modified by calcium nitrate and ammonium phosphate dibasic. The HA gradually increases with the increase of time cycles. The deposition of organic silicone group by the HMDSZ on the TPU substrate is hydrophobic surface. When deposition of O, the water contact angles (WCA) was changed to <10° and surface hydrophilicity. The materials were characterized by OM, SEM, FT-IR, XPS and XRD. The results showed that the NIPAM: AAc (1:1 mol) polymers possess macropores ranging from 2 to 20 μm, and their large numbers of carboxyl groups and hydroxyl groups result in a favorable adsorption capacity for HA. Swelling studies indicated that NIPAM: AAc (1:1 mol) was 446 ± 0.3%. This work provided a promising alternative method for the fabrication of polymer materials with tunable and interconnected pores structures for the HA. [ABSTRACT FROM AUTHOR]

New radiopaque nanocomposites were prepared using iodinated copolymers and cloisite 20A, as reinforcement agent. Iodinated copolymers were prepared through copolymerization of Methyl methacrylate and acrylic acid and subsequently modification of the P(MMA-co-AA) via 4-iodophenyl isocynate and 3,4,5-triiophenyl isocyanate for synthesis of 1I-P(MMA-co-AA) and 3I-P(MMA-co-AA) respectively. Preparation of the nanocomposites was carried out by the solution method using various amounts of organoclay. In order to investigate the effect of iodinated substituents on the morphology and thermal characteristics of the composite samples, the P(MMA-co-AA) was modified via phenyl isocyanate (PIC-P(MMA-co-AA)) and then the nanocomposites were prepared using cloisite 20A. All the nanocomposite samples were characterized by X-ray diffraction (XRD), scanning electron microscopoy (SEM), and thermogravimetric analysis (TGA). The X-ray visibility of the radiopaque nanocomposites was also explored using X-radiography. The results obtained indicated that the iodinated nanocomposites had an excellent radiopacity, and due to their biocompatibility, they could be used for medical applications. [ABSTRACT FROM AUTHOR]

This paper describes the synthesis and physicochemical characterization of Poly(N-isopropylacrylamide)-Chitosan-Poly(Acrylic acid) [PNIPAAm-CS-PAA] based polymeric microgels. Three different samples of multi-responsive (PNIPAAM-CS-PA) microgels were synthesized using various amounts of N N- Methylene bis-acrylamide (MBA) and Acrylic acid (AA) by free radical emulsion polymerization. The redox initiator Ammonium per sulfate (APS) was used to initiate the reactions while MBA was used as a crosslinking agent. The purified polymeric microgels were then characterized using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), Laser light scattering (LLS), Ostwald viscometry, dynamic Rheology and swelling/de-swelling measurements. From the spectroscopic result it was observed that all the reactions have been completed and the resultant microgels were successfully synthesized. The influence of various parameters such as, chemical composition and some external stimuli like temperature and pH on the physicochemical behavior of polymeric microgels was investigated through visual stability test, laser light scattering, viscometry and rheological measurement. The LLS analysis was performed to deduce the size, in the terms of hydrodynamic radius (R), of the microgel samples in aqueous media at different pH and temperature. From LLS analysis the microgels were found to be stable at all pH values above the pKa values (4.2) of AA in temperature ranges from 20 °C to 50 °C. With rising in temperature and pH causes aggregation of particles and decrease in stability of microgels due to the decrease in hydrophobicity. From the Rheological measurements, various physiochemical properties such as, elasticity, viscosity, shear stress, storage modulus, loss modulus, phase angle and complex viscosity of the microgels were gathered. The Ostowald viscometry was used to measure the flow viscosity of microgels at different pH and temperatures. The present observations reflect that the prepared samples are multi-responsive and their physicochemical behavior can be tuned very easily by changing their composition and/or varying the external stimuli. [ABSTRACT FROM AUTHOR]