Inter Layer Effect of Poly(acrylic acid) on the Multilayers Assembly on Cotton Fabric Using Bentonite/Halloysite/Chitosan Composite Matrix

Polyacrylic acid was synthesized in water by persulfate-initiated polymerization (solution polymerization) of glacial acrylic acid in the absence of a chain-transfer agent. The final product is odorless and colorless. Chelation for calcium ions using a calcium electrode show that our poly(acrylic acid) has a higher chelation capacity than that of existing commercial poly(acrylic acids). A design of experiments was performed to optimize the synthesis conditions to obtain poly(acrylic acid) with a high maximum chelation value. These studies also helped us to gain insight into its high chelation capacity. The chelation capacity for calcium reaches its highest values when polymerization near isothermal conditions is done ∼ 95°C with an acrylic acid concentration of ≤21 wt % and an addition time >1 h. These conditions favor higher molecular weight poly(acrylic acid) with a polydispersity ∼ 4. The dispersion properties of our poly(acrylic acid) are similar to those of the commercial ones. This dual capability of chelation and dispersion is absent in commercial chelants such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and their analogs. At pH > 7, chelation of calcium by our poly(acrylic acid) is much higher than that observed with EDTA. Characterization by NMR, Raman, FTIR, and molecular modeling are included in an attempt to understand structural features that can explain the higher chelation capacity of our atactic poly(acrylic acid).

Poly(acrylic acid) is a synthetic polymer that is polymerized from acrylic acid monomers. Poly (acrylic acid) is a high molecular weight polymer having good water solubility. Poly(acrylic acid) also exists in the cross-linked forms. Poly(acrylic acid) is an important polymer for making polymeric blends and nanocomposites. This state-of-the-art review is an endeavour to define the unique capabilities of poly (acrylic acid) to form high performance nanocomposites. The nanofiller nanomaterials including carbon nanotube, graphene, nanodiamond, and inorganic nanoparticles are promising nanofillers for a poly(acrylic acid) matrix. Consequently, the article discusses the following categories: poly(acrylic acid)/carbon nanotube, poly(acrylic acid)/graphene, poly(acrylic acid)/nanodiamond, and poly(acrylic acid)/inorganic nanoparticle nanocomposites. The nanocomposite characteristics are significantly enhanced with the added nanoparticles. Especially, the nanoparticles influenced the electrical conductivity, thermal stability, strength, biocompatibility, adsorption, and anti-bacterial features of the poly(acrylic acid) nanocomposites. Their high performance was related to the interface interactions between the matrix and the nanofillers. The poly (acrylic acid) derived nanocomposites have been used to form advanced hybrid materials for batteries, sensors, antibacterial, and water filters.

The need for the possibility of producing calcium carbonate crystals by the evaporation method within five minutes and the growth of different calcium carbonate polymorphs on chitin whiskers within the same time frame at room temperature necessitated these report. Chitin whiskers (CHWs) were used as insoluble substrates, while poly (acrylic) acid (PAA) is used as soluble additive. The crystals were grown in chitin whiskers, Poly (acrylic) acid and CHW/PAA composites. The volume fractions for aragonite, vaterite, and calcite are 0.10, 0.25, and 0.65, respectively, in the absence of chitin whiskers or Poly (acrylic) acid. Calcite and aragonite volume fractions decrease in favour of vaterite when PAA and or CHWs were added. SEM images in the absence of CHWs and PAA shows rhombohedral calcites that display steady and step like plane appearances with an average edge of between 1.3 and 1.4 μm. In the presence of only CHWs, the SEM images show a mixture of ellipsoidal and spherical shape vaterites. The spherical vaterites have smooth, rough, and some irregular surfaces. Rod-like aragonite polymorphs were seen when only PAA was used as the template. In the presence of both PAA and CHWs, the rhombohedral shape showed roughness with irregular faces.
 Keywords: Chitin whisker, Calcium carbonate, Calcium, vaterite aragonite, Polymorph, Mole fraction

We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10−4 mol/L, two orders of magnitude higher than that reported in the literature. The pH value of the solution was 3.9, and the hydrogen bonds between the intrinsic and ionized carboxylic acid groups formed dynamic networks, which captured aggregation-induced emission-active molecules (a tetra-quaternary ammonium modified tetraphenylethene derivative) inside the polymer coils and induced fluorescence emission. The hydrogen bonds can be classified as intra- or intermolecular; both can be probed based on the emission change of the tetra-quaternary ammonium modified tetraphenylethene probes. The effects of different external stimuli on the polymer chain dynamics were investigated using different metal cations (including Na+, Li+, Zn2+, Ni2+, Ca2+, and Co2+), different cation concentrations (1×10−6 to 4×10−4 mol/L), different poly(acrylic acid) molecular weights (5, 240, and 450 kDa), and different copolymers. The experimental results indicate that the long poly(acrylic acid) chains (high molecular weight) tend to form dense globular coils and exclude the probe molecules outside, which are robust and unsusceptible to water-soluble metal cations. However, the shorter poly(acrylic acid) chains tend to form intermolecular hydrogen bonds, which are helpful in capturing more probe molecules inside the networks, thus inducing stronger emission. Because of the dual functions of forming hydrogen bonds with carboxylic groups and acting as an acceptor of protons from the carboxylic acid group to form cationic species, copolymerization with acrylate amide [poly(acrylic acid)-co-poly(acrylamide)] can greatly affect the chain dynamics of poly(acrylic acid) segments, which is reflected by the drastically decreased emission intensity from the fluorescent probes.

We successfully introduced peroxide groups onto the surface of PU(Polyurethane) foam(10 PPI) through one atmospheric pressure plasma treatment and sequentially grafted PAAc(poly(acrylic acid)) on the surface of PU through radical copolymerization. The plasma treatment can generate large amount of peroxides on the surface of PU foam and the peroxide groups act as initiators for further grafting of PAAc in the monomer solution. To introduce large amount of peroxides on the surface of PU foam, we studied the effect of plasma rf-power and treatment time on the maximum grafting of PAAc. Through this study, we found that the optimum plasma treatment condition was the rf-power of 100 W and the treatment time of 100 s. On the other hand, we also studied the effect of graft reaction conditions such as temperature, monomer concentration and reaction time on the change of grafting degree (GD). The GD increased with increasing temperature and increased with reaction time before it leveled off at 3 h after reaction started. At low concentration of AAc, the GD was very low but it showed a maximum at the monomer concentration between 60 and 70%. The surface of the modified PU foam was qualitatively and quantitatively analyzed through the use of FT-IR and weight measurement, respectively. We also observed the surface change before and after plasma induced graft co-polymerization through photo and SEM analysis. Finally, we confirmed that the PU foams grafted with PAAc successfully immobilized lysozyme and other proteins from hen egg white.

Poly(acrylic acid)/modified attapulgite/zinc oxide composite (PAA/BF-ATP/ZnO) was prepared by acrylic acid, modified attapulgite (BF-ATP), triethoxy vinyl silane modified ZnO using in situ polymerization, and used in cotton fabric for improving the flame-retardant and UV protection properties. FT-IR and TEM results showed that PAA/BF-ATP/ZnO composite was successfully prepared. The stability, percent conversion, solid content and rotational viscosity of the composites with different ZnO content were investigated. The results showed that the conversion of composites was all above 98%, and these composites also had good stability, when the content of ZnO was 0.2–1%. Composite was loaded onto the cotton fabric by the dip-pad-dry method. The results showed that the thermal and flame retardant properties of cotton fabric were improved after treatment with the PAA/BF-ATP/ZnO, the LOI of the cotton fabrics with PAA/BF-ATP/ZnO was reached to 24.4%, which was 1.3% higher than that of PAA/BF-ATP treated cotton fabric. The burning rate was reduced to 0.68 mm/s, which was 0.24 mm/s lower than that of PAA/BF-ATP treated cotton fabric.

Cotton fabric with improved flame retardancy was prepared by introducing a zinc phosphate compound into cotton fabric using a layer-by-layer (LBL) deposition method with poly(acrylic acid) as a polymer electrolyte layer. In a vertical burning (VB) test, it was found that the flame retardancy improved as the number of depositions increased. As a result of thermogravimetric and inductively coupled plasma-atomic emission spectroscopy analyses, the residual amount increased to 20 wt % for the 20 deposited sample, and the weight ratio of Zn and P elements reached more than 40 wt %. As a result of SEM analysis, the cotton fibers not treated with LBL were destroyed after the VB test, but the shape of the fabric was maintained in the LBL-treated cotton fabrics. It was observed by TEM that numerous single crystals of about 10 nm formed on the surface of the sample subjected to the VB test. Through FT-IR and XPS analyses, it was confirmed that the zinc phosphate compound layer was formed by LBL deposition by the reaction between the phosphate anion and zinc cation. XRD analysis confirmed that the orthorhombic hopeite crystals produced by LBL deposition were transformed into zinc phosphate Zn3(PO4)2 crystals by flame during the VB test. These results show that flame retardancy was improved by a mechanism in which a noncombustible zinc phosphate barrier was formed during firing. These results are significant in suggesting a new method for preparing zinc phosphate single crystals of about 10 nm in size and providing anticorrosion coating for cotton fabric by an environmentally friendly LBL method.

The failure behaviour of glass polyalkenoate cements was investigated using a linear elastic fracture mechanics (LEFM) approach. Cements were based on Drayton gasifier slag and four poly(acrylic acid)s with number average molar masses ranging from 3.03 × 103 to 6.44 × 104. Cement properties were studied at time intervals of one, seven and twenty eight days. Compressive and flexural strengths of the cements increased with increasing molar mass of the poly(acrylic acid)s and time. The Young's modulii increased with time and were independent of poly(acrylic acid) molar mass. Fracture toughness increased with increasing molar mass of the poly(acrylic acid)s. Fracture toughness increases over an ageing time of one week and subsequently decreased over one month. Toughness increased with poly(acrylic acid) molar mass, these increases being most pronounced at higher molar mass. The toughness values decreased with time for the higher molar mass cements, which is consistent with increased crosslinking of the poly(acrylic acid) chains and reducing molecular flow at the crack tip. Plastic zone size increased with poly(acrylic acid) molar mass and decreased with time for lower molar mass cements, remained constant for intermediate molar mass cements and increased with high molar mass cements.

Poly(acrylic acid) block copolymers as stabilizers for dispersion polymerization

Synthesis of comb type and semi-interpenetrating networks of acryloyl- l-proline methyl ester and poly (acrylic acid) for Cu (II) immobilization

ABSTRACTPoly(acrylic acid)-graft-fatty alcohol are synthesized from the esterification of polyacrylic acid with octadecanol and docosanol. The characterization of poly(acrylic acid)-graft-fatty alcohol was performed by attenuated total reflection–Fourier transform infrared spectroscopy. The thermal stability performances and phase change behaviors of poly(acrylic acid)-graft-fatty alcohol were examined by using thermogravimetric analysis system and differential scanning calorimetry. The results indicate that the poly(acrylic acid)-graft-fatty alcohol polymeric phase change materials possess good phase change properties and provide a suitable working temperature range. The heating process phase change enthalpy is measured between 112 and 122 J g−1, and the freezing process phase change enthalpy is found between 118 and 126 J g−1. The decomposition of poly(acrylic acid)-graft-fatty alcohol polymeric phase change materials started at 177°C and reached a maximum of 380°C. All of the obtained poly(acrylic acid)-graft-fatty alcohol polymeric phase change materials improved latent heat storage capacity in comparison with the pristine poly(acrylic acid) polymer. With the obtained results we conclude that, these materials promise a great potential in thermal energy storage applications.

Synthesis of tethered-polymer brush by atom transfer radical polymerization from a plasma-polymerized-film-coated quartz crystal microbalance and its application for immunosensors

Functionalized polymeric nanocarriers have been recognized as drug delivery platforms for delivering therapeutic concentrations of chemotherapies. Of this category, star-shaped multiarm polymers are emerging candidates for targeted delivery of anti-cancer drugs, due to their compact structure, narrow size distribution, large surface area and high water solubility. In this study, we synthesized a multi-arm poly(acrylic acid) star polymer via MADIX/RAFT polymerization and characterized it using NMR and size exclusion chromatography. The poly(acrylic acid) star polymer demonstrated excellent water solubility and extremely low viscosity, making it highly suited for targeted drug delivery. Subsequently, we selected a hydrophilic drug, cisplatin, and a hydrophobic nitric oxide-donating prodrug, O2-(2,4-dinitrophenyl) 1-[4-(2-hydroxy)ethyl]-3-methylpiperazin-1-yl]diazen-1-ium-1,2-diolate, as two model compounds to evaluate the feasibility of using poly(acrylic acid) star polymers for delivery of chemotherapeutics. After synthesizing and characterizing two poly(acrylic acid) star polymer-based nanoconjugates, poly(acrylic acid)-cisplatin (acid-Pt) and poly(acrylic acid)-nitric oxide prodrug (acid-NO), the in vitro drug release kinetics of both acid-Pt and acid-NO were determined at physiological conditions. In summary, we have designed and evaluated a polymeric nanocarrier for sustained-delivery of chemotherapies, either as a single treatment or a combination therapy regimen.

ABSTRACTWe describe here the first example of the synthesis of 4‐arm star poly(acrylic acid) for use as a water‐soluble drag reducing agent, by applying Cu(0)‐mediated polymerization technique. High molecular weight 4‐arm star poly(tert‐butyl acrylate) (Mn = 3.0–9.0 × 105 g mol−1) was first synthesized using 4,4′‐oxybis(3,3‐bis(2‐bromopropionate)butane as an initiator and a simple Cu(0)/TREN catalyst system. Then, 4‐arm star poly(tert‐butyl acrylate) were subjected to hydrolysis using trifluoroacetic acid resulting in water‐soluble 4‐arm star poly(acrylic acid). Drag reduction test rig analysis showed 4‐arm star poly(acrylic acid) to be effective as a drag reducing agent with drag reduction of 24.3%. Moreover, 4‐arm star poly(acrylic acid) exhibited superior mechanical stability when compared with a linear poly(acrylic acid) and commercially available drag reducing polymers; Praestol and poly(ethylene oxide). The linear poly(acrylic acid), Praestol, and poly(ethylene oxide) all showed a large decrease in drag reduction of 8–12% when cycled 30 times through the drag reduction test rig while, in contrast, 4‐arm star poly(acrylic acid) demonstrated much higher mechanical stability. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 335–344

The effect of poly(acrylic acid), poly(acrylamide), and poly (vinyl alcohol) on the attrition grinding of Illinois No. 6 coal was examined. The grinding efficiency was significantly increased by poly(acrylic acid), slightly decreased by poly(acrylamide), and unaffected by poly(vinyl alcohol). The beneficial effect of poly(acrylic acid) was most pronounced when it was used as an additive in a 55% solids slurry. The beneficial effect decreased with increasing grinding time and was most effective at lower pH values where the poly(acrylic acid) existed in the acid or partially neutralized form. When the mixture of coal slurry plus poly(acrylic acid) was neutralized with alkali to pH 6.62, the beneficial effect disappeared. Subsequent froth flotation, using kerosene and MIBC, of coal ground with poly(acrylic acid) was essentially unaffected by the presence of the additive. Some potential economic advantages of using poly(acrylic acid) as a grinding aid are pointed out.