Polymerization In Aqueous Media Research Articles

Ferrogels based on entrapped metallic iron nanoparticles in a polyacrylamide network: extended Derjaguin-Landau-Verwey-Overbeek consideration, interfacial interactions and magnetodeformation.

A new kind of ferrogel with entrapped metallic iron nanoparticles causing unusual magnetodeformation is presented. Crosslinked polyacrylamide (PAAm) based ferrogels embedded with iron nanoparticles (MNPs) were synthesized by free radical polymerization in aqueous medium. Spherical iron MNPs with average diameter 66 nm were synthesized by the electrical explosion of wire and modified by interfacial adsorption of linear polyacrylamide (LPAAm). Extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) calculations based on the superposing of van der Waals, electrostatic, steric, and magnetic contributions showed that polymeric encapsulation of nanoparticles by LPAAm is one of the most suitable pathways for preparing stable aqueous dispersions of iron nanoparticles. Microcalorimetry confirmed the presence of strong interfacial adhesion forces between LPAAm chains and the surface of iron nanoparticles. By keeping the same crosslinking density of a polymer network (i.e. 100 : 1, monomer to crosslinker ratio) and varying the initial monomer concentration, an influence of the extent of polymer network reticulation on the mechanical properties and subsequently, magneto-elastic properties was demonstrated. It was found that the upper limit of the shear modulus for the synthesis of a new kind of polyacrylamide based ferrogel to exhibit any usable magnetodeformation under the application of a uniform external magnetic field of 420 mT is ca. 1 kPa. Magnetodeformation of cylindrical ferrogel samples was observed in the form of an overall volume contraction accompanied by a homogeneous decrease in all dimensions. The deformation was found to be maximum (around 10%) for the aspect ratio of 1/1 and it was lower and similar for the samples with 1/2 and 2/1 aspect ratios. Such a type of magnetic response is significantly different from the behavior observed in the existing reports on ferroelastomers.

SYNTHESIS AND CHARACTERIZATION STUDIES OF A SERIES OF N-VINYL IMIDAZOLE-BASED HYDROGEL

In this study, poly[( N -vinyl imidazole)-co-(2-dimethylaminoethyl methacrylate)] hydrogels with various mole percentages of monomers were prepared by free radical solution polymerization in aqueous media. N,N' -methylenebisacrylamide and 2,2'-azobisisobutyronitrile were used as cross-linker and initiator, respectively. A Fourier transform infrared spectrophotometer, scanning electron microscope and thermogravimetric analyzer were used for the characterization of the hydrogels. The swelling behavior of the hydrogels in aqueous solution were investigated at pH 6.0 and 25°C. The results showed that swelling characteristics were affected by 2-dimethylaminoethyl methacrylate content of the copolymeric hydrogel. The swelling degree of hydrogels increased from 4.2 g g –1 to 25.4 g g –1 by increasing 2-dimethylaminoethyl methacrylate concentration from 0 to 15% with respect to the total moles of monomers.

Facile Synthesis of H2O2-Cleavable Poly(ester-amide)s by Passerini Multicomponent Polymerization

We report the straightforward synthesis of two types of H2O2-cleavable poly(ester-amide)s (P1 and P2) via the Passerini multicomponent polymerization (P-MCP) of 4-formylbenzeneboronic acid pinacol ester with 1,6-diisocyanohexane and 1,6-hexanedioic acid or a polyethylene glycol (PEG) dicarboxylic acid. The H2O2-cleavable phenylboronic acid ester was integrated into the polymer backbone by the in situ formed benzyl ester bond. GPC and 1H NMR confirmed the complete H2O2-triggered degradation of these polymers in aqueous medium by a mechanism of sequential oxidation of phenylboronic acid ester and self-immolative elimination. Compared with the hydrophobic polymer P1, the PEG-based water-soluble polymer P2 degraded much faster even at a lower H2O2 concentration. Cytocompatible nanoparticles of polymer P1 loaded with fluorescent Nile red were fabricated, and controlled release of Nile red in response to H2O2 was achieved, thus, demonstrating the utility of these polymers as potential H2O2-responsive delivery vehicles.

Formation of poly(acrylic acid)/alumina composite via in situ polymerization of acrylic acid adsorbed within oxide pores

Poly(acrylic acid) (PAA) adsorption on alumina has been widely studied to provide composite materials. This work attempts to form PAA/alumina composites via in situ polymerization of acrylic acid pre-adsorbed on alumina. Effective acrylic acid adsorption in porous γ-alumina was realized with incipient wetness impregnation method. The adsorbed acrylic acid was then polymerized via reversible addition fragmentation transfer (RAFT) polymerization in aqueous medium. The solution properties of the as-prepared PAA/alumina composites were further investigated. Dissociation constant measurements illustrate that PAA molecules residing in alumina exhibited pKa more basic than pure PAA. The composites showed higher lead adsorption capability than pristine alumina. However, there correlation of lead adsorption capability and the adsorbed PAA amount in PAA/alumina samples did not follow a straightforward pattern. Ion adsorption difference among various PAA segments was proposed.

Amphiphilic poly-N-vinylpyrrolidone nanoparticles as carriers for non-steroidal, anti-inflammatory drugs: In vitro cytotoxicity and in vivo acute toxicity study

Polymeric nanoparticles were prepared from self-assembled amphiphilic N-vinylpyrrolidone polymers in aqueous media and evaluated as novel carriers of indomethacin, a non-steroidal, anti-inflammatory drug. It was determined that these nanoparticles could be created in spherical morphologies with sizes less than 100nm, narrow size distributions and high indomethacin contents(up to 35%) combined with high drug loading efficiencies(up to 95%). In cytotoxicity tests using the human embryonic stem cell derived fibroblasts (EBF-H9) and hepatocellular carcinoma cells (HepG2), the indomethacin-loaded polymeric nanoparticles showed higher cell viability compared to that of free indomethacin at the same concentration. The median LD50 values, determined by the Litchfield–Wilcoxon method, were 55–70mg/kg body weight depending on the polymer molecular design in both mice and rats. Based on the acquired results, these novel amphiphilic poly-N-vinylpyrrolidone nanoparticles can be considered as potential carriers for new, highly efficient, injectable drug delivery systems for hydrophobic drugs such as indomethacin.

Alkynylated Cellulose Nanocrystals Simultaneously Serving as Chiral Source and Stabilizing Agent for Constructing Optically Active Helical Polymer Particles

To take advantage of the chirality of cellulose nanocrystals (CNCs) and to develop novel chiral polymer materials, alkynylated CNCs (alkynyl-CNCs) were prepared and copolymerized with an achiral acetylenic monomer through suspension polymerization in aqueous media. The chirality of the alkynyl-CNCs was efficiently transferred to racemic helical polymer chains, by which inducing predominantly one-handed polymer helicity. Moreover, alkynyl-CNCs simultaneously acted as a comonomer and stabilizing agent, directly providing optically active microparticles (400–800 μm) constructed by chirally helical polymer chains. So the alkynylated CNCs played triple roles in our strategy: chiral source, comonomer, and stabilizing agent for performing suspension polymerizations. SEM images showed the successful formation of microparticles with regular spherical morphology, while circular dichroism spectra demonstrated the formation of one-handed helical polymer chains and optical activity of the microparticles thereof. The p...

Simultaneous catalytic reduction of nitroarenes using silver nanoparticles fabricated in poly(N-isopropylacrylamide-acrylic acid-acrylamide) microgels

Monodisperse multi-responsive poly(N-isopropylacrylamide-acrylic acid-acrylamide) [P(NIPAM-AAc-AAm)] polymer microgels were synthesized by precipitation polymerization in aqueous medium. Silver nanoparticles were fabricated inside the microgels by in situ reduction method. Poly(N-isopropylacrylamide-acrylic acid-acrylamide) [P(NIPAM-AAc-AAm)] microgels and Ag-poly(N-isopropylacrylamide-acrylic acid-acrylamide) [Ag-P(NIPAM-AAc-AAm)] hybrid microgels were characterized by Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy (UV–vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The hybrid microgels were found to be temperature and pH sensitive in aqueous medium. They have long term stability under various conditions of pH of the medium. The hybrid microgels were used as catalysts for simultaneous reduction of various nitro compounds in aqueous medium. Nitroarenes like o-nitroaniline (o-NA), p-nitroaniline (p-NA), p-nitrophenol (p-NP) and nitrobenzene (NB) were individually and simultaneously reduced to corresponding aminoaromatic compounds by sodium borohydride in the presence of Ag-poly(N-isopropylacrylamide-acrylic acid-acrylamide) hybrid microgels catalyst. Catalytic activity of the hybrid microgels for individual and simultaneous reduction of nitroarenes was compared with each other. The retardation in catalytic reduction of each nitroarene in the presence of other nitroarenes was explained on the basis of simultaneous adsorption. Various factors affecting the catalytic reduction of p-nitroaniline (p-NA) like catalyst dose and pH of the medium were also investigated. Rate of reduction of p-nitroaniline was found to be increased with increase of catalyst dose and pH of the medium.

Well-Defined Zwitterionic Microgels: Synthesis and Application as Acid-Resistant Microreactors

This paper describes the synthesis, swelling behavior, and applications of well-defined narrowly dispersed zwitterionic (ZW) microgels prepared by dispersion polymerization in aqueous media. Microgel stability was achieved through precise control of the dispersant composition, timely addition of a cross-linker after the nucleation stage, and the utilization of ionic initiators. Dispersion polymerization allowed for incorporation of both hydrophilic and hydrophobic comonomers, including acrylamide (AAm) and dopamine methacrylamide (Dopa-MA). The broad variety of compositions created many opportunities for practical applications such as encapsulation of mineral acids and synthesis of metal nanoparticles. The swelling behavior of ZW-co-AAm microgels in 6 M HCl was particularly interesting: whereas ZW moieties remained stable in contact with the strong acid, the amide groups underwent hydrolysis to carboxylic acid, resulting in microgel contraction and acid release. Zw-co-Dopa-MA microgels were employed as pa...

Facile fabrication of double‐walled polymeric hollow spheres with independent temperature and pH dual‐responsiveness for synergetic drug delivery

ABSTRACTA dual‐responsive double‐walled polymeric hollow sphere (PHS) serving as a candidate for synergetic drug delivery platform is prepared by a simple and green template polymerization in aqueous medium. The PHS, comprised of thermo‐responsive crosslinked poly(N‐isopropylacrylamide) (PNIPAM) as the inner shell and pH‐responsive crosslinked poly(methacrylic acid) (PMAAc) as the outer shell, is assembled through self‐removal of the thermo‐responsive template from a core‐triple shell structure by free radical polymerization with sequential addition of reactants. The discrete double‐shell structure renders the PHS independent temperature and pH‐controlled swelling/shrinking capability. Taking the advantage of two compartmentalized internal spaces (the core and the interlayer spaces) with independent temperature‐ and pH‐dependent behaviors, two model drugs representing the small molecule and the macromolecule are loaded in selective locations of the PHS. Two drugs show dramatically different release profiles according to environmental temperature and pH, due to the localization of drugs and the stimuli‐dependent property of its protective shells. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44335.

Catalytic reduction of 4‐nitrophenol using silver nanoparticles‐engineered poly(N‐isopropylacrylamide‐co‐acrylamide) hybrid microgels

Nearly monodisperse poly(N‐isopropylacrylamide‐co‐acrylamide) [P(NIPAM‐co‐AAm)] microgels were synthesized using precipitation polymerization in aqueous medium. These microgels were used as microreactors to fabricate silver nanoparticles by chemical reduction of silver ions inside the polymer network. The pure and hybrid microgels were characterized using Fourier transform infrared and UV–visible spectroscopies, dynamic light scattering, X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry and transmission electron microscopy. Results revealed that spherical silver nanoparticles having diameter of 10–20 nm were successfully fabricated in the poly(N‐isopropylacrylamide‐co‐acrylamide) microgels with hydrodynamic diameter of 250 ± 50 nm. The uniformly loaded silver nanoparticles were found to be stable for long time due to donor–acceptor interaction between amide groups of polymer network and silver nanoparticles. Catalytic activity of the hybrid system was tested by choosing the catalytic reduction of 4‐nitrophenol as a model reaction under various conditions of catalyst dose and concentration of NaBH4 at room temperature in aqueous medium to explore the catalytic process. The progress of the reaction was monitored using UV–visible spectrophotometry. The pseudo first‐order kinetic model was employed to evaluate the apparent rate constant of the reaction. It was found that the apparent rate constant increased with increasing catalyst dose due to an increase of surface area as a result of an increase in the number of nanoparticles.

Recovery of metals from simulant spent lithium-ion battery as organophosphonate coordination polymers in aqueous media

An innovative approach is proposed for the recycling of metals from a simulant lithium-ion battery (LIBs) waste aqueous solution. Phosphonate organic linkers are introduced as precipitating agents to selectively react with the metals to form coordination polymers from an aqueous solution containing Ni, Mn and Co in a hydrothermal process. The supernatant is analyzed by ICP-AES to quantify the efficiency and the selectivity of the precipitation and the materials are characterized by Scanning Electron Microscopy (SEM), Powder X-Ray Diffraction (PXRD), Thermogravimetric Analyses (TGA) and nitrogen gas sorption (BET). Conditions have been achieved to selectively precipitate Manganese or Manganese/Cobalt from this solution with a high efficiency. This work describes a novel method to obtain potentially valuable coordination polymers from a waste metal solution that can be generalized on any waste solution.

Stimuli Responsive Self‐Assembly of 3‐(Octyloxy)‐3‐Oxopropyl Acrylate‐Co‐Acrylic Acid Polymer in Aqueous Media

AbstractA novel copolymer based on 3‐(alkyloxy)‐3‐oxopropyl acrylate and acrylic acid was synthesized and characterized. Surface tension and fluorescence probe techniques (using N‐phenyl‐1‐naphthylamine as a probe) were employed to evaluate the surface properties of the amphiphilic copolymer. The copolymer was found to reduce the surface tension of water to 40–46 mN/m depending on the pH of the medium. The critical aggregation concentration of the copolymer determined by surface tension measurements was found to be 0.28 mg/ml at pH 4, 1.13 mg/ml at pH 8, and 1.44 mg/ml at pH 10, very close to those obtained by steady state fluorescence probe techniques (0.21, 1.13 and 1.48 mg/ml, respectively, at pH 4, 8, and 10). The pH‐induced structural transitions of the copolymer were also studied using steady state fluorescence with pyrene and 1,6‐diphenyl‐1,3,5‐hexatriene as probes, dynamic light scattering and transmission electron microscopy. The protonation of pendant carboxylate groups at acidic pH makes the aggregate compact and rigid. Conversely, ionization of the carboxylate groups under alkaline conditions resulted in larger aggregates.

Synthesis and characterization of inorganic–organic polymer microgels for catalytic reduction of 4‐nitroaniline in aqueous medium

Poly(N‐isopropylacrylamide‐co‐acrylic acid) [p(NiPA‐co‐AAc)] microgel particles were synthesized by free radical precipitation polymerization in aqueous medium. Silver nanoparticles (Ag NPs) were fabricated inside the microgels by in situ reduction method. UV–visible, Fourier transform infrared (FTIR), and dynamic light scattering techniques were used for characterization of pure microgels. The Ag‐p(NiPA‐co‐AAc) hybrid microgels were characterized by UV–visible, FTIR, X‐ray diffraction, and transmission electron microscopy. The hybrid microgel system was used as a catalyst for reduction of 4‐nitroaniline (4‐NA) in aqueous medium. The kinetics of the catalytic reduction of 4‐NA under various conditions of concentration of hybrid microgels, sodium borohydride (NaBH4), and 4‐NA was monitored by UV–visible spectrophotometry. It was found that the value of apparent rate constant (kapp) increases with increase of concentration of NaBH4 and catalyst dosage while it remains constant at various concentrations of 4‐NA. The kinetic data were used to elaborate the conversion of 4‐NA into p‐phenylenediamine on the basis of electron relaying effect of Ag NPs present inside the microgels. POLYM. COMPOS., 39:645–653, 2018. © 2016 Society of Plastics Engineers

Fabrication of pH‐Responsive Hydrogel and Its In Vitro and In Vivo Evaluation

ABSTRACTThe present research work deals with the development of pH‐responsive hydrogel by free radical polymerization in aqueous media to protect the rabeprazole sodium from acidic environment of stomach. Swelling behavior of hydrogels that was observed in buffer of various pH indicated highly pH‐dependent swelling of hydrogels. Characterization of pH‐responsive hydrogels by FTIR, SEM, and thermal analysis revealed that hydrogel has porous structure, favors swelling, drug loading, and drug release at a specific site in gastrointestinal tract and thermally more stable than parent polymer. In comparison with simple drug solution and hydrogel formulations, pharmacokinetic parameters of hydrogels formulations showed a significant difference in Cmax values of (CMC‐g‐AA) CA and the same oral dose of rabeprazole sodium was 87.28 ± 12.671 and 61.263 ± 5.37 ng/mL, respectively, Tmax of graft copolymer matrices CA (4.43 h) was significantly (P < 0.05) higher than drug solution (1 h) and area under curves (AUCs) for CA (952.25 ± 191 ng⋅h/mL) was significantly (P < 0.05) higher than the drug solution (83.67 ± 8.28 ng⋅h/mL) indicated the effect of dosage form would last for longer duration. Thus, in vitro and in vivo drug release studies of hydrogels proved their controlled release behavior with preferential delivery into alkaline pH environment and for a prolonged period of time.

Evaluation of Surfactants-Assisted Folic Acid-Loaded Pectin Submicrospheres: Characterization and Hemocompatibility Assay.

Folic acid is used for preventing and treating multiple diseases and disorders, administered in the form of oral supplements. The present research work was aimed to study the influence of two non-ionic surfactants Poloxamer and Tween 80 (Polysorbate 80) on pectin submicrospheres formulations. Typical natural polymer pectin was used to encapsulate folic acid by cross linking method. The resultant submicrospheres contributed to improve the aqueous solubility to enhance the bioavailability of folic acid. During investigation, it was observed that pectin polymers influenced kinetics of the rate of reaction more intensively than the surfactants. The physical phenomenon caused the change in their size, shape and chemistry of pectin polymers transforming into submicrospheres in aqueous condition. The characteristic differences of submicrospheres were assessed by scanning electron microscopy, differential scanning calorimetry and Fourier-transform infrared spectroscopy. The average diameters of the submicrospheres ranged between 250 and 500nm. The encapsulation efficiency of submicrospheres ranged between 80 and 96%. The characteristic swelling behavior of lyophilized submicrospheres was influenced by the ratio of pectin polymers and folic acid used in the formulations. The submicrospheres systems exhibited controlled release of folic acid due to the pH-dependent solubility of pectin polymers in aqueous medium. The submicrospheres showed good haemocompatibility suggesting them to be promising candidates for oral delivery.

Biomass Vanillin-Derived Polymeric Microspheres Containing Functional Aldehyde Groups: Preparation, Characterization, and Application as Adsorbent.

The contribution reports the first polymeric microspheres derived from a biomass, vanillin. It reacted with methacryloyl chloride, providing monomer vanillin methacrylate (VMA), which underwent suspension polymerization in aqueous media and yielded microspheres in high yield (>90 wt %). By controlling the N2 bubbling mode and by optimizing the cosolvent for dissolving the solid monomer, the microspheres were endowed with surface pores, demonstrated by SEM images and mercury intrusion porosimetry measurement. Taking advantage of the reactive aldehyde groups, the microspheres further reacted with glycine, thereby leading to a novel type of Schiff-base chelating material. The functionalized microspheres demonstrated remarkable adsorption toward Cu(2+) (maximum, 135 mg/g) which was taken as representative for metal ions. The present study provides an unprecedented class of biobased polymeric microspheres showing large potentials as adsorbents in wastewater treatment. Also importantly, the reactive aldehyde groups may enable the microspheres to be used as novel materials for immobilizing biomacromolecules, e.g. enzymes.

Glyco-nanoparticles toward nanobiological applications: Synthesis and controlled self-assembly of poly-/oligosaccharide containing block copolymers

Event Abstract Back to Event Glyco-nanoparticles toward nanobiological applications: Synthesis and controlled self-assembly of poly-/oligosaccharide containing block copolymers Issei Otsuka1*, Sami Halila1* and Redouane Borsali1* 1 CERMAV-CNRS, Grenoble Alpes University, Physico-chemistry and self-assembly of glycopolymers, France Introduction: Self-assembly of amphiphilic block copolymers (BCPs) that consist of biomacromolecules as one of their building blocks has attracted growing interest in nanobiological applications. Poly-/oligosaccharides are one of the most abundant biomacromolecules which can be obtained from biomass. Thus, our research group has reported various oligosaccharide containing BCPs and their self-assembly in solution and film states. In this presentation, we focus on controlled self-assembly of the oligosaccharide containing BCPs into glyco-nanoparticles in aqueous media for therapeutic molecular delivery application. Materials and Methods: The oligosaccharide containing BCPs were synthesized through copper-catalyzed azide-alkyne cycloaddition of propargyl-functionalized oligosaccharides (maltoheptaose (MH), xyloglucan oligosaccharides (XGO), and beta-cyclodextrin (CD)) with azido end-functionalized polymers (PS, PMMA, PCL and PNIPAM). Self-assembly of the oligosaccharide containing BCPs were performed mainly by nanoprecipitation and thermal aggregation methods. The details were reported in our related publications[1]-[6]. Results: The oligosaccharide containing BCPs such as MH-b-PS and MH-b-PMMA were self-assembled into micellar nanoparticles that consist of hydrophilic oligosaccharide shells and hydrophobic polymer cores in aqueous media. The BCPs composed of oligosaccharides and PNIPAM were self-assembled into micellar and vesicular nanoparticles in water by slowly increasing the temperature above the lower critical solution temperature (LCST) of the PNIPAM block. Hydrophobic active guest molecules such as dyes, drugs, and gold nanoparticles were successfully encapsulated into those nanoparticles through self-assembly process. These results were demonstrated by light scattering and imaging techniques including transmission electron microscopy. Discussion: Oligosaccharide containing amphiphilic BCPs can self-assemble into nanoparticles that consist of shells of hydrophilic oligosaccharides and cores of hydrophobic polymers in aqueous media due to energetic repulsion effects between the hydrophobic polymers and water. The hydrophobic guest molecules can be stabilized in the hydrophobic core of the nanoparticles due to hydrophobic effect. Thermo-responsive solubility variation (from hydrophilic to hydrophobic) of the PNIPAM blocks about the LCST induced the self-assembly of the BCPs such as MH-b-PNIPAM. The hydrodynamic radii of those nanoparticles were controlled from tens to hundreds nanometers by this means. Conclusion: The glyco-nanoparticles that can encapsulate active guest molecules were successfully prepared by controlled self-assembly of the oligosaccharide-containing BCPs. The radii of these glyco-nanoparticles were controlled within the size necessary for targeting tumor cells (10-200 nm) by enhanced permeability and retention (EPR) effect. The thermo-responsive formation and dissolution of the glyco-nanoparticles is very important and significant for controlled therapeutic molecular delivery. The authors acknowledge financial support from CNRS, the PolyNat Carnot Institute, and Labex ARCANE (ANR-11-LABX-0003-01).

Aqueous biphasic systems composed of ionic liquids and polypropylene glycol: insights into their liquid-liquid demixing mechanisms.

Novel ternary phase diagrams of aqueous biphasic systems (ABSs) composed of polypropylene glycol with an average molecular weight of 400 g mol(-1) (PPG-400) and a vast number of ionic liquids (ILs) were determined. The large array of selected ILs allowed us to evaluate their tuneable structural features, namely the effect of the anion nature, cation core and cation alkyl side chain length on the phase behaviour. Additional evidence on the molecular-level mechanisms which rule the phase splitting was obtained by (1)H NMR (Nuclear Magnetic Resonance) spectroscopy and by COSMO-RS (Conductor-like Screening Model for Real Solvents). Some systems, for which the IL-PPG-400 pairs are completely miscible, revealed to be of type "0". All data collected suggest that the formation of PPG-IL-based ABSs is controlled by the interactions established between the IL and PPG, contrarily to previous reports where a "salting-out" phenomenon exerted by the IL over the polymer in aqueous media was proposed as the dominant effect in ABS formation. The influence of temperature on the liquid-liquid demixing was also evaluated. In general, an increase in temperature favours the formation of an ABS in agreement with the lower critical solution temperature (LCST) phase behaviour usually observed in polymer-IL binary mixtures. Partition results of a dye (chloroanilic acid, in its neutral form) further confirm the possibility of tailoring the phases' polarities of IL-PPG-based ABSs.

Synthesis of water-soluble acryl terpolymers and their anticorrosion properties on mild steel in 1 mol·L− 1 HCl

Two water soluble acryl terpolymers containing polyvinyl alcohol, acrylamide/acrylic acid and vinyl sulphonic acid (VSA) were synthesized by free radical polymerization in aqueous medium. The morphological structure of the polymers were analysed using FTIR and 1H NMR, while the thermal properties were analysed by TGA and DSC. The inhibitive action of the terpolymers on corrosion of mid-steel in 1mol·L−1 HCl was studied using gravimetric, potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) at 303K. Both the polymers provided inhibition efficiency around 90% which clearly demonstrate that the grafted polymers have effective corrosion inhibiting ability on MS corrosion.

Homophase and heterophase polymerizations of butyl acrylate mediated by poly(acrylic acid) as a reversible addition–fragmentation chain-transfer agent

The radical polymerization of n-butyl acrylate in organic, aqueous, and water–alcohol media in the presence of poly(acrylic acid) containing a trithiocarbonate group within the chain is studied for the first time. It is shown that in nonselective solvents (1,4-dioxane and DMF) poly(acrylic acid) serves as a reversible addition–fragmentation chain-transfer agent and the triblock copolymer poly(acrylic acid)–block–poly(n-butyl acrylate)-–block-poly(acrylic acid) is formed. In aqueous and aqueous–organic media (under conditions of emulsion, dispersion, and miniemulsion polymerizations as well as polymerization-induced selfassembly), the block copolymer being formed additionally serves as a stabilizer of polymer–monomer particles. The sizes of these particles and the molecular-mass characteristics of the resulting polymers may be controlled via variation in the concentration ratio of the components. It is found that, during polymerization in aqueous media, there is the formation of spherical polymer particles that preserve their morphology in thin films prepared via precipitation of the synthesized dispersion.