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Aramid based on poly (p‐phenylene terephthalamide) (PPTA) is widely concerned as high‐performance materials. Herein, copolymerized aramid nanofibers (CANFs) were prepared for the first time by a direct bottom‐up polymerization method without additives. Three kinds of third monomers of m‐phenylenediamine, 4,4′‐diaminodiphenyl ether, and 2,5‐dichloro‐1,4‐phenylenediamine were separately copolymerized in PPTA and transformed into nanofiber dispersions in water medium. The characterization results revealed the relationship between the morphology of products and the structure as well as dosages of the different kinds of monomers, which was explained by the influence on conjugate regularities of the PPTA molecules. Furthermore, CANFs were used to build aramid paper blended in pure PPTA nanofibers, and the mechanical and insulation properties of composite paper were improved significantly, which would be of potential use as the new building block for aramid composite materials. [ABSTRACT FROM AUTHOR]

Copolymerization of cationic monomer and nonionic macromonomer in water‐ether mixture solution is useful for preparing the functional polymer. Copolymer of diallyldimethylammonium chloride (DMDAAC) and a nonionic block polyether macromonomer (PEP‐65) has been found that has very well reverse demulsification performance, but the polymerization phenomenon cannot be described by any reported polymerization method. In this paper, the copolymerization behavior including polymer mechanism, polymerization kinetics, and reactivity rate of DMDAAC and PEP‐65 in the mixture solution of water and propylene glycol methyl ether (PGME) was studied for explaining the special copolymerization phenomenon and its flotation performance for treating oily wastewater was also investigated. The results showed that DMDAAC‐PEP‐65 copolymerization in water‐PGME mixture solution has four stages and has both characteristics of emulsion polymerization and dispersion polymerization. In addition, the copolymer also has excellent flotation performance. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, a hydrophobic monomer (HM) that has a cationic double alkyl-substituted group bonded to the nitrogen atom was first synthesized. Then a hydrophobic poly(vinyl alcohol) (PVA) was prepared by a radical solution copolymerization of vinyl acetate (VAc) with the HM followed by an alcoholysis reaction in alkaline conditions. The structures of HM and hydrophobically modified PVA (H-PVA) were confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The effect of hydrophobic cationic segments on crystallization behaviors, mechanical properties, morphology, solution viscosity, and hydrophobic property were investigated. The results indicated that the crystallinity decreased from 37.2% of pure PVA to the minimum 23.2% of H-PVA with the incorporation of 1.15 mol % HM. The thermal decomposition temperature of H-PVA increased by about 50 °C compared with that of pure PVA. The viscosity of the H-PVA solution was several times higher than that of the corresponding unmodified PVA solution over the whole shear rate range, which demonstrated that the H-PVA had good shear-resistance ability. Furthermore, the contact angle was significantly increased from 55.1° to 115° with the incorporation of only 0.83% HM, which illustrated that the H-PVA had high hydrophobicity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43888. [ABSTRACT FROM AUTHOR]

Although acrylic acid‐based superabsorbent hydrogels (SAHs) are widely used in hygiene and personal care applications, the low degrees of true ionization in such SAHs under practical application places a limit on the degree of superabsorbency that can be achieved. Herein, the preparation and optimization of SAHs based on copolymers of acrylic acid (AA) with 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS), a strong acid comonomer that remains ionized at all relevant physiological pH values, is described. AA‐AMPS recipes optimized using a central composite design response surface method demonstrate significantly enhanced absorbance under load (AUL) values (>15–20% increase) and comparable centrifuge retention capacity (CRC) values compared to the corresponding AA‐only controls while maintaining strong mechanics even in the swollen state (as much as twice the modulus of the commercial AA‐based superabsorbent). The simplicity of this recipe, coupled with the reproducible achievement of the improved superabsorbency properties using a small adaptation of the commercial SAH synthesis protocol, makes AA‐AMPS superabsorbent hydrogels potential candidates for use in commercial hygiene products. [ABSTRACT FROM AUTHOR]

A novel autocatalytic phthalonitrile monomer [4,4′‐(((((oxy‐bis [4,1‐phenylene]) bis (azanediyl)) bis (methylene)) bis (2‐methoxy‐4,1‐phenylene)) bis (oxy)) diphthalonitrile, OPD] is obtained by nucleophilic substitution of 4‐nitro‐phthalonitrile and bisphenol compound [4,4′‐(((oxy bis [4,1‐phenylene]) bis (azanylylidene)) bis (methanylylidene)) bis (2‐methoxyphenol)]. Bisphenol compound is a reductant with secondary amine groups of Schiff base derived from the reaction of vanillin and 4,4′‐diaminodiphenylether. The OPD monomer has a self‐catalytic polymerizing reaction. OPD monomer has good processability, and the processing window was 130°C. Moreover, OPD polymer [poly(OPD)] shows higher glass‐transition temperature (345°C). The 5% and 10% thermal decomposition temperatures of poly(OPD) and char yield at 800°C are 407, 451°C, and 69%, respectively. To further improve the properties of poly(OPD), the OPD monomer was modified by multi‐functional fluorene‐based benzoxazine monomers (MFFB) due to their excellent reaction activities. The results showed that OPD/MFFB systems had high reaction activities. The similar thermal stabilities between OPD and MFFB can give stable and excellent thermal stability to the poly(OPD/MFFB). Compared with poly(OPD), the Tg values of poly(OPD/MFFB) were significantly increased, and their stiffness values were reduced. The tensile, flexural, and impact properties for poly(OPD/MFFB) were improved significantly. [ABSTRACT FROM AUTHOR]

The objective of the present study is to synthesis and characterize the novel functional stilbene containing copolymer‐clay nanocomposites, make clear the influence of organo‐clay on peculiarities of the nanocomposites and emphasis on the dynamic mechanical properties. For this purpose, poly(acrylamide‐co‐trans‐stilbene)‐organo‐MMT [poly(AAm‐co‐Stb)‐O‐MMT] nanocomposites were synthesized by in situ interlamellar solution copolymerization with organically modified montmorillonite (O‐MMT) clay due to its superior properties gives to copolymer. The effect of different amounts of O‐MMT clay incorporation to the nanocomposite structure and properties of copolymer/O‐MMT clay nanocomposites were characterized by X‐ray diffraction (XRD), Attenuated Total Reflectance‐Fourier Transform Infrared, Thermogravimetric Analysis, Differential Scanning Calorimeter, Dynamic mechanic analysis (DMA) methods. XRD analysis showed the basal spacing of the O‐MMT increased in nanocomposites and this indicated that the intercalation of the copolymer chain into the O‐MMT interlayer performed and nanocomposites were obtained successfully. Additionally, copolymer/O‐MMT nanocomposites exhibited improved thermal properties at higher temperatures than the pristine copolymer. DMA results enlightened the viscoelastic properties of synthesized materials. DMA results indicated that obtained nanocomposites have higher mechanical strength because of the interaction/compatibility in between copolymer chains and O‐MMT. In the light of these results, this work has introduced new perspectives on design, fabrication and viscoelastic properties of certain organo‐clay copolymer nanocomposites for the synthesis of new materials and potential industrial applications. [ABSTRACT FROM AUTHOR]

In order to improve the toughness, wear resistance, and combustion properties of the monomer casting nylon (MC nylon) materials, the polydimethylsiloxane (PDMS) segment is bonded to the nylon molecular chain by copolymerization. PDMS/MC nylon copolymers are prepared via in situ anionic polymerization with macro‐activator based on PDMS terminated with hexamethylene diisocyanate. The effects of different macro‐activator content on the mechanical properties, water absorption, thermal stability, friction and wear properties, and combustion properties of the copolymers are characterized. The results show that the impact strength of the copolymer improves significantly (optimally increases by 2.6 times) and the water absorption rate decreases with the increase of PDMS content. The introduction of the silicon–oxygen structure reduces the peak heat release rate of copolymer materials (optimally decreases about 28.7%), while it promotes the decomposition of the system, resulting in a slight decrease in the thermal stability of the materials. Adding 5 wt % PDMS can decrease the wear loss of MC nylon from 6.2 mg of pure nylon to 1.6 mg. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48753. [ABSTRACT FROM AUTHOR]

ABSTRACT: The wheat straw cellulose‐based hydrogels were synthesized by graft copolymerization followed by semi‐interpenetrating network technology. The prepared hydrogels were characterized through various methods including Fourier transform infrared spectra, scanning electron microscope, thermogravimetric analysis, and X‐ray photoelectron spectroscopy. Batch adsorption experiments were carried out to investigate the adsorption performances of hydrogels toward Cu(II) ions. The results suggested that the introduction of semi‐interpenetrating network polymers, sodium alginate and poly(vinyl alcohol), could greatly enhance the adsorption property of hydrogels. And the wheat straw cellulose‐g‐poly(potassium acrylate)/sodium alginate hydrogel showed a highest Cu(II) ions adsorption capacity of 130 mg/g. The equilibrium isotherm and adsorption kinetics were also studied. Besides, the mass transfer coefficients and the thermodynamics of Cu(II) ions adsorption were also probed. Finally, the X‐ray photoelectron spectroscopy analysis further demonstrated that the Cu(II) ions adsorption was mainly via complexation reaction of NH2 and O‐containing groups in hydrogels. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46680. [ABSTRACT FROM AUTHOR]

ABSTRACT A new comb-shaped copolymer was synthesized by free radical copolymerization of 2-acrylamide-2-methyl propane sulfonic acid, acrylamide, N-vinyl-2-pyrrolidone, and allyl polyoxyethylene ether (APEG) monomers. The copolymer was evaluated as a filtrate loss reducer in water-based drilling fluid at 180 °C environment, and found to work well without causing high viscosity effect. Composition of the copolymer was determined by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. FTIR, X-ray diffraction,, and environmental scanning electron microscopy characterizations were used to probe the filtrate loss mechanism of the comb-shaped copolymer. Thermogravimetry and differential scanning calorimetry results showed that thermal degradation of the copolymer is not obvious before 293.6 °C. The copolymer is found to be superior to its commercially available counterparts for controlling filtrate loss volume and maintaining a steady viscosity after 180 °C aging. Higher content of APEG in the copolymer helps maintain rheological properties of the drilling fluid after aging and reduces filtrate loss volume. The morphology of the copolymer in aqueous solution displays a comb-shaped 3D structure and shows clear adsorption onto clay particles. The working mechanism for copolymer is that anchoring groups bind the copolymer onto clay particles through different binding mechanisms, while colloidal suspension stability is achieved by steric hindrance and electrostatic repulsion, as well as through PEG segment intercalation into clay lamellae. The copolymer is able to cover and seal the micro-holes in the mud cake even at high temperature to reduce permeability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45989. [ABSTRACT FROM AUTHOR]

ABSTRACT Well-defined poly(styrene- block-dimethylsiloxane) copolymers (PS- b-PDMS) with low polydispersity index ( Mw/ Mn) and different compositions were synthesized by sequential anionic polymerization of styrene (S) and hexamethyl(ciclotrisiloxane) (D3) monomers. Synthesized PS- b-PDMS copolymers were characterized by 1H-nuclear magnetic resonance, size exclusion chromatography, Fourier transform infrared spectroscopy, and transmission electron microscopy. The physicochemical characterization determined that block copolymers have molar mass values close to ∼135,000 g mol−1, narrow Mw/ Mn < 1.3, and chemical composition ranging from low to intermediate PDMS content. Blends of these copolymers with a commercial polystyrene (PS) were obtained by melt mixing and subsequently injection. Films obtained were flexible, and showed lower transparency than the original PS matrix. On the other hand, a 10 wt % incorporation of PS- b-PDMS copolymers leads to better mechanical performance by enhancing elongation at break (∼8.8 times higher) and opacity values (∼18 times higher). In addition, UV-Vis barrier capacity of the resulting blends is also increased (up to 400% higher). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45122. [ABSTRACT FROM AUTHOR]

ABSTRACT Polyacrylamide copolymers (PAMVT) microspheres were prepared through inverse emulsion polymerization by using acrylic acid (AA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS) as functional monomers, N, N′-methylene bis-acrylamide (MBA) as crosslinker and modified vermiculite (MVMT) with the single-factor experiments. The initial and swelled particle sizes were tested through the dynamic light scattering (DLS). The swelled particle size under the optimum conditions could be 1.98 μm. The structure was characterized through Fourier transform infrared (FTIR), which indicated that vermiculite has successfully modified and the polymerization reaction was completed. The scanning electron microscopy (SEM) shows that MVMT was evenly filled with PAM copolymers. The water absorption capacity can be up to 80.2%. The recovery efficiency of the water flooding was increased from 69.33% to 77.56%. All these results indicated that the microspheres emulsions could be used as profile control agent to enhance the recovery efficiency. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44918. [ABSTRACT FROM AUTHOR]

ABSTRACT The starch-based macroporous superabsorbent polymer (St-MP SAP) was synthesized by graft copolymerization of acrylic acid (AA)/2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) onto cassava starch through free radical polymerization method by using sodium bicarbonate (SHC) as porogen. The monomer conversion kinetics was investigated to determine the suitable time of adding SHC so as to produce large numbers of stable and uniform pores inside the SAP. Introduction of SHC led to the formation of increasing pores and loose structure in St-MP SAP, the decrease of shear storage modulus ( G′). With increasing SHC content, the size of the macro pores increased and the wall thickness decreased, and a large number of micropores can be observed on the pore walls. Meanwhile the equilibrium swelling ratio of St-MP SAP first increased and then decreased, and reached maximum as high as 1878 g/g and 119 g/g in distilled water and NaCl aqueous solution respectively for the sample with presence of 0.8 wt % SHC. Furthermore, the swelling rate constant ( k) increased monotonously and fast swelling was presented. The macro and micropore structure in St-MP SAP enabled water to flow by capillary effect with much fewer obstructions, and the specific surface area increased, with the result that more hydrophilic groups can get in touch with water molecules rapidly. By introduction of SHC, the water molecules which can form hydrogen bonds with St-MP SAP molecules decreased, resulting in the decrease of the binding capacity of water molecules and water retention property. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44855. [ABSTRACT FROM AUTHOR]

ABSTRACT A novel polysulfone was easily synthesized by alternating copolymerization of norbornene with sulfur dioxide (SO2) via free radical copolymerization and coordination copolymerization. Compared with other olefin derivatives, norbornene is a cyclic olefin having a larger steric hindrance, which is easily copolymerized with SO2, and the obtained poly(norbornene sulfone)s have excellent thermomechanical and optical properties. The effect of the different polymerization methods on the copolymerization reaction was analyzed in detail. The results suggested that different polymerization mechanisms exist in the different polymerization methods and affect the thermal stability and optical properties of the polysulfone. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44534. [ABSTRACT FROM AUTHOR]

ABSTRACT A triblock copolymer, containing a polyethylene glycol (PEG) block and two symmetrical poly(2-(dimethylamino)ethyl methacrylate) (PDM) blocks, was synthesized by using PEG-based macroinitiator with copper-mediated living radical polymerization. The conductivity tests showed that the copolymer exhibited switchable responsiveness to CO2, i.e., a relatively high conductivity of solution can be switched on and off by bubbling and removing of CO2. According to the nuclear magnetic resonance results, the CO2-switchable conductivity variation could be attributed to protonation and deprotonation of tertiary amine groups in PDM blocks. Moreover, at a proper weight concentration 0.5%, the copolymer aqueous solution displayed a CO2-switchable viscosity variation. Scanning electron microscopy, cryogenic transmission electron microscopy, and dynamic light scattering characterization jointly demonstrated that the viscosity variation was the result of a CO2-switchable vesicle-network aggregate structure transition. This structure transition can actually be attributed to a hairpin-line molecular configuration conversion in terms of the reasonable mechanism discussion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44417. [ABSTRACT FROM AUTHOR]

ABSTRACT Monomer reactivity ratios are important parameters used in copolymerization kinetics to predict the rate of polymerization, copolymer composition and monomer sequence length, and by extension, molecular weight and distribution of the final product. Batch aqueous solution copolymerizations of acrylic acid (AA) and itaconic acid (IA) are performed at various feed compositions. Polymerizations are categorized into low (<11 wt %) conversion and higher (< 30 wt %) conversion data sets for analysis. Due to the limited solubility of IA in the reaction mixture, the feed composition of IA in all polymerizations is constrained to lower than 25 mol %. Conversion is determined by gravimetric methods, and copolymer composition via 1H-NMR spectroscopy. All data are analyzed using the error-in-variables model (EVM) method. Two analyses are used, one with the EVM approach and another with a novel Direct Numerical Integration (DNI) coupled with the EVM method. The DNI/EVM approach yields values of rAA = 0.36 and rIA = 1.62 for the reactivity ratios. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44014. [ABSTRACT FROM AUTHOR]

ABSTRACT In this work, acrylate copolymer has been fabricated by graft copolymerization of acrylate monomer (EMA:EA is 70:30) with functional TiO2 nanoparticles, which was surface-modified by the silane coupling agent methacryloxy propyl trimethoxyl silane (KH570) to attach active ends. The structure and properties of the copolymer were characterized by FT-IR, FE-SEM, differential scanning calorimetry, thermogravimetric analysis, ultraviolet-visible spectra, and discoloration. Characterization revealed that functional TiO2 particles were grafted onto the chain of the acrylate copolymer and the acrylate copolymer showed excellent photo-oxidative stability and transparency. The acrylate copolymer was applied to protect and consolidate ancient ivory by surface coating without destruction of chemical structure. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43291. [ABSTRACT FROM AUTHOR]

ABSTRACT Copolymers of 1,1,1,3,3,3-hexafluoroisopropyl methacrylate (HFIPM) and tert-butyl methacrylate (TBM) were prepared by conventional radical copolymerization as a novel binders for pressure-sensitive paints (PSP). The monomer reactivity ratios rHFIPM and rTBM were determined as 0.45 and 0.67, respectively. The glass transition temperature of the copolymers increased from 77 to 126°C with increasing mole fraction of TBM units in the copolymer. The PSP were formed by combining the resulting copolymers and 5,10,15,20-tetrakis(pentafluorophenyl)porphinato platinum(II). The pressure and temperature sensitivities of the PSPs were measured at air pressures ranging from 5 to 120 kPa and at temperatures ranging from 0 to 60°C. Modified Stern-Volmer plots indicated slight increases in the pressure sensitivity, but significant decrease in the temperature sensitivity as the mole fraction of HFIPM units increased in the copolymer. Applying a theoretical model to our calibration data, we inferred that luminescence quenching is primarily responsible for increasing the temperature sensitivity in the resulting copolymers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43316. [ABSTRACT FROM AUTHOR]

This work focuses on the synthesis of a new class of copolymer materials consisting of traditional vinyl monomers (essentially, vinyl acetate, ethyl acrylate, and methyl methacrylate) and copper (II) methacrylate (Cu(II)MA) intended to be used as surface modification agents in electrochemical quantifications of organic and inorganic analytes. Voltammetry assays showed that when deposited on glassy-carbon electrode (GCE), Cu(II)MA-based copolymers are very promising materials to be applied in electrochemical determinations, exhibiting high analytical signal in the oxidation and reduction peaks during quantification of potassium hexacyanoferrate (III) in comparison to a bare GCE, contributing to increase the effective electrode area. When employed for the determination of ascorbic acid, PVAcCu(II)MA/GCE exhibited performance similar to that of the bare GCE. Polymers characterizations showed that glass transition temperature of the Cu(II)MA-based materials increased in approximately 10-20°C, as consequence of the copper present in molecular structure of the copolymer chains (bidentate bridging coordination mode). Energy-dispersive X-ray spectroscopy measurements of Cu(II)MA monomer and Cu(II)MA-based copolymers showed strong characteristic peaks K&#945 and Kβ at 8.04 and 8.90 keV, respectively, with an average amount of copper of 99%. The performance of the Cu(II)MA-based copolymers modified electrodes is strongly dependent on the amount of copper into the copolymer chains and consequently on the monomers conversion. [ABSTRACT FROM AUTHOR]

ABSTRACT Synthesis and characterization of a series of linear copolymers with liquid crystalline side chains is reported. Methacrylate monomers containing cyanobiphenyl as a mesogenic group were prepared. These monomers were then copolymerized with 2-ethylhexyl acrylate in varying molar ratios. The structure and composition of the monomers and corresponding polymers were determined by 1H-NMR, elemental analysis and size-exclusion chromatography. Thermal properties of the polymers were studied using differential scanning calorimetry, polarized optical microscopy, and X-ray scattering techniques. Increasing mesogen content resulted in an increase of the glass transition temperature of the copolymers. In addition, above a threshold mesogen content the copolymers exhibited smectic mesophases. Using a solution casting technique, a membrane was fabricated to study single gas transport behaviors. Permeabilities, were in the order of CO2 > propylene > O2 > N2 > CH4 > propane. Diffusion coefficients correlated well to Lenard-Jones Diameter. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42694. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, redox-initiated free radical graft copolymerization of microcrystalline cellulose (MCC) and methyl methacrylate (MMA) has been carried out in aqueous media to develop a novel cellulose-based copolymer. Cerium ammonium nitrate was used as the initiator in the presence of nitric acid. Effects of monomer concentration, initiator concentration, polymerization time, and polymerization temperature on the graft parameters of copolymers were studied. The successful grafting copolymerization between MCC and MMA was validated through attenuated total reflection, wide-angle X-ray diffraction, field-emission scanning electron microscopy, and thermal gravimetric analysis. In comparison to native MCC, the resultant copolymers exhibited enhanced thermal stability and better compatibility with natural rubber, suggesting its potential application as reinforcement material in rubber industry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42666. [ABSTRACT FROM AUTHOR]

ABSTRACT The copolymerization modified poly(p-phenylene terephthalamide) containing 2-(4-aminophenyl)−5-aminobenzimidazole (PABZ) units in the main chain was synthesized and the corresponding poly-p-phenylene-benzimidazole-terephthalamide (PBIA) fibers were prepared by wet spinning. The HCl, the by-product released during polymerization, can complex with PABZ units to prevent the formation of hydrogen bonding between PABZ units, resulting in amorphous PBIA fibers and a lower glass transition temperature ( Tg). Therefore, for the purpose of gaining strong hydrogen bonding and high orientation degree at the same time in PBIA fibers, two-step drawing-annealing processing was adopted. The as-spun PBIA/HCl complex fibers were drawn first at 280°C, higher than the Tg of the PBIA/HCl complex fibers and lower than the decomplexed temperature of HCl, which temporarily suppresses the formation of hydrogen bonding and crystallization. Subsequently, the fibers were annealed to reform hydrogen bonding between PABZ units and crystallization via decomplexation of HCl at 400°C. However, when the drawing is above the decomplexed temperature of HCl, the decomplexation of HCl begins to occur which leads to the reform of hydrogen bonding and crystallization, and the tensile strength of the drawn-annealed PBIA/HCl complex fibers decreases with a decrease in the HCl content of fibers. The tensile strength of two-step drawn-annealed fibers increased by approximately 15% compared to that of one-step drawn PBIA/HCl complex fibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42482. [ABSTRACT FROM AUTHOR]

ABSTRACT Copolymers of lactic acid with mandelic or salicylic acid were synthetized through ring-opening polymerization (ROP) and tested as protective coatings for stones. Most notably, glass transition temperature ( Tg), hydrophobicity, and UV barrier properties were increased, making these materials more suitable as protective coating for outdoor stones than poly(lactic acid). A Tg of 76°C was obtained for the alternating copolymer lactic acid/mandelic acid and it was considerably higher than the one of poly(lactic acid) with similar molecular weight (50-55°C). Furthermore, the introduction of a perfluorinated moiety as chain-end group, using a perfluoro alcohol as initiator of the ROP process, allowed to increase the hydrophobicity and stability of the new coatings. These polymers showed a good protective efficiency when applied on marble stones and preliminary stability tests under solar light showed low degradation, good stability to photo-oxidative conditions, and negligible color changes after an aging time of 1000 h. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42323. [ABSTRACT FROM AUTHOR]

ABSTRACT Graft copolymerization of styrene onto dealkaline lignin by ferrous chloride and hydrogen peroxide coinitiator has been achieved successfully. The influence of temperature and reaction time as well as the amount of the styrene monomer, initiator, and catalyst on the grafting copolymerization was investigated. The optimum reaction conditions were determined as follows: c (styrene) = 20.00 mmol, c (H2O2) = 5.00 mmol, c (FeCl2) = 0.10 mmol, T = 30°C and t = 48 h. The optimum yield ( Y), total conversion (TC), grafting efficiency (GE), and degree grafted (DG) values were 96.6, 96.3, 59.5, and 53.7%, respectively. The copolymer of lignin grafted PS was separated and characterized by elemental analysis, differential scanning calorimetry, Fourier transform infrared, thermogravimetry analysis, field emission-scanning electron microscopy, gel permeation chromatography, and nuclear magnetic resonance. It was demonstrated that the solubility what the copolymer exhibited turned out to be the very reverse of the original lignin. The surface properties and structure of lignin were completely changed after grafting copolymerization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41900. [ABSTRACT FROM AUTHOR]

ABSTRACT A series of copoly(imide alkyl ether)s were synthesized to explore surface migration of fluorinated alkyl ether blocks (AEFO)s. Mechanical and surface properties of solution cast, thermally imidized films were determined. Incorporation of the AEFO oligomers at loading levels up to 5 wt % resulted in a slight decrease (usually less than 10%) in tensile modulus. Surface migration of the AEFOs raised the advancing water contact angle from approximately 80° to above 95° for the copolymer systems. The composition at which addition of more AEFO further increased water contact angle values was related to the number of fluorine atoms in the perfluorinated side chains. Surface excess concentration of the AEFO at different loading levels was calculated from X-ray photoelectron spectroscopy results. At higher AEFO loading levels, the surface excess concentration was relatively constant suggesting formation of stable structures within the bulk similar to micelle formation in surfactant solutions. Based on these results, it was determined that surface saturation occurred with the fluorinated AEFO species at loading levels as low as 1 wt % engendering changes in surface properties while retaining the bulk imide properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41538. [ABSTRACT FROM AUTHOR]

ABSTRACT Five titanium complexes TiCl3(OAr) (Ar = C6H5, 2,6-Me2C6H3, 2,6- i-Pr2C6H3, 2,6- t-Bu2C6H3, 4-Me-2,6- t-Bu2C6H3) were immobilized, respectively, on MgCl2 in semibatch reaction to form supported catalysts for olefin polymerization. Comparing with the catalysts prepared by immobilizing TiCl3(OAr) onto MgCl2 in batch reaction, the catalysts prepared by semibatch reaction have lower titanium content and higher ArO/Ti ratio. The aryloxy-containing catalysts studied in this work showed higher ethylene/1-hexene copolymerization activity and higher 1-hexene incorporation rate than the blank catalyst when activated by triisobutylaluminum. Similar effects of the aryloxy ligand were observed when the copolymerization is conducted in the presence of hydrogen. Introducing aryloxy ligand in the catalysts either by semibatch or batch reaction caused similar effects of enhancing copolymerization activity and α-olefin incorporation rate. Mechanism of the effects of aryloxy ligand has been discussed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41329. [ABSTRACT FROM AUTHOR]

ABSTRACT The ionic strength (IS) of polyelectrolyte solutions plays an important role in influencing reaction kinetics. The largely unstudied effect of IS on monomer reactivity ratios and copolymerization rates of acrylamide (AAm) and acrylic acid (AAc), in the form of sodium acrylate (NaAc), is investigated. Salt addition affects the nature of overall charges of the polyelectrolyte solution and diminishes the electrostatic repulsions between reacting chains. Therefore, changing the IS of the solution by incorporating salts affect not only the point estimates of the monomer reactivity ratios but also the overall behavior of the copolymerization (with a transition to azeotropic behavior). Experimental results on copolymerization rates confirm the observed trends in reactivity ratio behavior. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40949. [ABSTRACT FROM AUTHOR]

ABSTRACT Novel amphiphilic copolymers were synthesized and characterized by 1H NMR using Hyaluronic acid (HA) as a hydrophilic part and phosphatidylethanolamine (PE) including 1,2-dimiristoyl-sn-glycerol-3-phosphatidylethanolamine (DMPE) and 1,2-distearoyl-sn-glycerol-3-phosphatidylethanolamine (DSPE) as a hydrophobic segment. The newly developed HA-PE copolymers form a micelle in an aqueous media. The micellar properties, including critical micelle concentration (CMC) with pyrene as a fluorescence probe and micelle morphology, using transmission electron microscopy were assessed. It was found that the CMC values for HA-DMPE and HA-DSPE were 15.5 and 13.4 μg/mL, respectively. Also micelles were spherical in shape and within the size range of 162-214 nm. The solubility of cholesterol, a highly hydrophobic compound, was enhanced to 0.25 mg/mL which is much higher than it is in water (0.0001 mg/mL). In vitro cytotoxicity assay of HA-PE copolymers showed no toxicity on human breast cancer cell line (MCF-7). These results suggest that HA-PE micelles could be considered as a promising carrier for delivery of hydrophobic compounds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40944. [ABSTRACT FROM AUTHOR]

Triglyceride in the waste soybean oil (WSO) was used as coupling agent to synthesize a linear styrene-butadiene-styrene (SBS) triblock copolymer. The reaction occurred via a living anionic polymerization of styrene-butadiene block copolymer (SB) using n-butyllithium as initiator and cyclohexane as solvent and followed by the coupling reaction with the added WSO. Gel permeation chromatography (GPC) showed that for all SB-Li precursors except the one with the Mn of 1000 g/mol, the resultant products consisted of two different sizes, one with the nearly comparable size with the precursor, the other with a Mn two-fold higher than the precursor. On the other hand, the reaction of the SB-Li precursor with the Mn of 1000 g/mol and the WSO only resulted in forming the molecule with a Mn two-fold higher than the precursor. The results from the GPC and spectral analysis supported that upon the nucleophilic attack the ester group of the triglyceride in the WSO was broken, giving the SB-C(O)-fatty acid susceptible to the second the nucleophilic attack, thus forming the coupled product. The size of the SB-Li precursor, the SB-Li : WSO molar ratio, the S:B weight ratio and the coupling time were found to influence on the coupling efficiency. However, the size of the SB-Li precursor showed highest impact on the coupling efficiency at which the larger the SB-Li precursor, the lower the coupling efficiency. Regardless of the low coupling efficiency of the WSO, the WSO was found to be a potential coupling agent for the formation of the linear triblock copolymer. This was because the SBS triblock copolymer containing high SB diblock copolymers and prepared by the WSO showed slightly higher tensile strength than the one with less SB diblock copolymers prepared by a traditional coupling agent. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40684. [ABSTRACT FROM AUTHOR]

ABSTRACT Polysuccinimide (PSI) was first synthesized via thermal polycondensation reaction using maleic anhydride and urea as the starting materials. Then, polyaspartic acid-glutamic acid (PASP-GLU) grafted copolymers were prepared from PSI and GLU. The structure of PASP-GLU was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The molecular weight was measured by gel permeation chromatography, and the crystallinity was analyzed by X-ray diffraction spectra. The effects of grafting ratio on the builder performances were systematically studied, as well as on the thermal property and biodegradability. It is demonstrated that as the grafting ratio of GLU increases, the thermal stability and biodegradability decrease a little, but still maintain in high level. Most importantly, the incorporation of GLU into side chains significantly improves the builder performance of PASP-GLU. The maximum values for calcium ion chelating power, dispersion power of CaCO3, and alkali-buffer ability reach 233.2 mg, 108.9 mg, and 1.70 mL, respectively, at the highest grafting ratio, in which the dispersion power of CaCO3 and alkali-buffer ability are even better than that of sodium tripolyphosphate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40282. [ABSTRACT FROM AUTHOR]

The reactor blends (RBs) with bimodal molecular weight distribution on the base of ultrahigh molecular weight polyethylene (UHMWPE) and low molecular weight random ethylene/1-hexene copolymers (CEH) were synthesized by two-step processes including ethylene polymerization followed by ethylene/1-hexene copolymerization over rac-(CH3)2Si(Ind)2ZrCl2/methylaluminoxane catalyst. The four series of blends differed in a composition of copolymer fraction that was varied in a wide range (from 3.0 to 37.0 mol % of 1-hexene). The differential scanning calorimetric study shows the double melting behavior of the net semicrystalline CEHs, which can be attributed to intramolecular heterogeneity in chain branch distribution. The introduction of CEHs leads to the modification of nascent RB crystalline and amorphous phases. Physical and tensile properties as well as melting indexes of the materials depend not only on the percentage of copolymer fraction that varied from 6.9 to 35.8 wt % but also on its composition. The increase of copolymer fraction with high content of 1-hexene (≥11.0 mol %) in the blends leads to the change of the character of stress-strain curves; the materials behave as elastomers. Controlled regulation of copolymer fraction characteristics in the synthesis yields RBs combining the enough high strength, good plastic properties with enhanced melting indexes as compared with the net UHMWPE. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40151. [ABSTRACT FROM AUTHOR]

A series of aqueous latexes with solid contents of 56%-59% were synthesized by binary emulsion copolymerization of vinylidene chloride (VDC) with an acrylate, namely methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), hexyl acrylate (HA), or 2-ethylhexyl acrylate (EHA). Differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy showed that the acrylate units with short ester side-chains, such as MA and EA, made the copolymers hard and the crystallization tendency of their PVDC segments was reduced. Hydrophobic acrylates with relatively long ester groups, such as HA and EHA, gave flexible copolymers, and favored the crystallization of their PVDC segments. BA endowed the copolymers with medium flexibility and crystallization tendency. As coating materials, the copolymers bearing MA and EA adhered poorly to the tinplate before or after 100 hr of salt-spray corrosion, whereas those bearing BA, HA, or EHA showed good adhesion to tinplate when they had little or no crystallinity. After 100 hr of salt-spray corrosion, only BA-VDC80, containing 80% VDC, retained both excellent adhesion to metal and excellent barrier performance. Further study demonstrated that BA-VDC80 could protect tinplate from rusting for at least 250 hr under harsh salt-spray corrosion. Scanning electron microscopy, FTIR-attenuated total reflectance spectroscopy and DSC were used to evaluate the corroded BA-VDC80 film. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40192. [ABSTRACT FROM AUTHOR]

ABSTRACT Bisphenol A-based epoxy acrylate (BABEA), a commercial ultraviolet (UV)-curable material, was introduced as a new manufacturing material for facile fabrication of epoxy-functionalized micro-zone plates through UV-initiated copolymerization using glycidyl methacrylate (GMA) as the functional monomer. The poly (BABEA- co-GMA) was highly transparent in visible range while highly opaque when the wavelength is less than 295 nm, and of high replication fidelity. X-ray photoelectron spectroscope (XPS) results indicated the existence of epoxy groups on the surface of the poly (BABEA- co-GMA), which allowed for binding protein through an epoxy-amino group reaction. A fabrication procedure was proposed for manufacturing BABEA based epoxy-functionalized micro-zone plates. The fabrication procedure was very simple; obviating the need of micromachining equipments, wet etching or imprinting techniques. To evaluate the BABEA-based epoxy-functionalized micro-zone plates, α-fetoprotein (AFP) was immobilized onto the capture zone for chemiluminescent (CL) detection in a noncompetitive immune response format. The proposed AFP immunoaffinity micro-zone plate was demonstrated as a low cost, flexible, homogeneous, and stable assay for α-fetoprotein (AFP). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39787. [ABSTRACT FROM AUTHOR]

ABSTRACT Cassava starch- graft-polymethacrylamide (PMAM) copolymers were synthesized by a free-radical-initiated polymerization reaction, and the products were tested for their efficiency as flocculants and textile sizing agents. The highest percentages of grafting and monomer conversion were 79.9 and 78.0%, respectively. The grafted starches were characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The average molecular weight of PMAM chains in the grafted starches ranged from 15.9 to 30.8 × 105 g/mol. The grafted starches exhibited a higher peak viscosity and paste stability in comparison to the native starch (NS). Dynamic mechanical analysis showed that grafting provided fairly shear-stable hydrogels, and the highest storage modulus obtained was 17,900 Pa compared to 1879 Pa for NS. The flocculation studies demonstrated the superiority of starch- g-PMAM over cassava starch and PMAM as an efficient flocculant. The tensile strength of cotton yarns sized with the starch-grafted copolymer was significantly higher (104 MPa) compared to that sized with NS (34 MPa). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39810. [ABSTRACT FROM AUTHOR]

ABSTRACT One kind of branched Poly(vinyl alcohol) has been synthesized via common radical copolymerization of vinyl acetate in methanol by adding a bifunctional monomer Allyl methacrylate (AMA) followed by saponification. The comonomer AMA has two reactive double bonds that can provide the branching points to macromolecule chain structure. With these reactive points, the copolymer with long chain branches can be obtained. The long chain branches bring the copolymer higher viscosity by the entanglement of them between macromolecules and strong hydrogen bonding between long chain branches. The viscosity of the water solutions increased with the amount of the comonomers' addition increased. The branched PVA has good water maintenance properties at relatively high temperature. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4608-4612, 2013 [ABSTRACT FROM AUTHOR]

ABSTRACT We investigated the effect of organic filler and the degree of crosslinking on the performance of a hydrogel/filler system to control its diffusion and mechanical properties. A series of poly(acrylic acid) gels filled with polystyrene (PS) nanoparticles at well-controlled filler loading levels was synthesized by free radical polymerization in the presence of a crosslinking agent. Three different concentrations of the crosslinking agent (methylene bis-acrylamide), that is, 5 mg/(g of AAc), 10 mg/(g of AAc), and 20 mg/(g of AAc), were used. The hydrogel crosslinked to the least extent that included a high amount of PS showed fast swelling rates, high equilibrium swelling ratios, and the highest pH sensitivity. Three gel/filler combinations including the gel without filler, gel/filler mixture, and gel/filler copolymerization were considered. The PS particles of ∼40 nm in diameter, which were used as the fillers, were prepared by microemulsion polymerization. Copolymerization of styrene and AAc having different reactivities ratios was achieved by a seed-microemulsion polymerization with the crosslinking agent. The gel/filler mixture showed the highest swelling rate and the gel/filler copolymer resulted in highly enforced mechanical properties and the highest pH sensitivity. The incorporation of filler by copolymerization to mechanically enforce the equilibrium swelling hydrogel was more efficient than the increase of crosslinking degree. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3574-3587, 2013 [ABSTRACT FROM AUTHOR]

pH-Sensitive organic-inorganic copolymers of hydrogels were developed as drug delivery systems (DDS) to improve the swelling behavior of polyacrylic acid (PAA). They were represented through FTIR, TGA and XRD characterization which revealed that the functional groups of methacryl-phenyl polyhedral oligomeric silsesquioxane (POSS) were successfully added to the acrylic acid (AA) molecular chains through radical solution polymerization. The DSC test results indicate that the addition of POSS could improve the thermal properties of the copolymers. The swelling properties at the pH range of 1.25-8.01 exhibited the pH sensitivity of POSS/AA copolymers (POSS- co-AA) and the lower swelling ratio in acidic conditions indicated that the DDS had low amount of release in SGF; this phenomenon suggested that the copolymer was available as DDS of theophylline. And it was proved by drug release curve and scanning electron microscopy. Since the addition of POSS reduced the release rate of theophylline and prolonged the release time of the drug, the concentration range of theophylline could remain low for an extended duration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

In this article, the experimental results obtained in the copolymerization of ethylene with polar monomers using a silylated α-diimine nickel catalyst are described and compared with those obtained with a non-silylate similar one. The results show that the introduction of a siliyl group in the para-position of the imine moiety turns the catalyst less sensitive toward polar functionalities. However, the reactivity observed in copolymerization reactions was found to be reduced both the global polymerization and incorporation rates. Molecular modeling calculation allowed us to understand both the preferred insertion mode and the intermediate product structures for E/MMA copolymerization. Photodegradation studies showed that the presence of polar groups in the copolymers increases their rate of oxidation and turn them more easily degradable. The stabilization performed by Tinuvin 770 showed that for long-exposure times, it is not very effective regardless it is only mixed or grafted to the copolymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Hydroxyethylcellulose- g-methoxypoly (ethylene glycol) (HEC- g-PEG) graft copolymers were synthesized through the etherification reaction between the hydroxyl group of hydroxyethylcellulose (HEC) and iodinated methoxypoly (ethylene glycol) (PEG-I), which was prepared on the basis of two-step reaction. Fourier transforms infrared spectrum (FTIR), nuclear magnetic resonance (NMR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and iodide oxidation method were used to prove the success of synthesis of graft copolymer. Furthermore, the comparative studies of electro-osmotic flow (EOF) and protein separation in bare-fused silica, HEC and HEC- g-PEG-coated capillary were performed in capillary electrophoresis (CE). The results showed that HEC- g-PEG-coated capillary presented efficient EOF suppression ability and excellent resisting protein adsorption ability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Synthesis, characterization, and amidoximation of diaminomaleonitrile-functionalized polyvinyl alcohol (PVA) grafts were studied. Ceric ammonium nitrate (CAN) was used as an initiator in an aqueous nitric acid medium under N2 atmosphere. Optimum conditions for grafting were as follows: monomer concentration [DAMN] = 1.4 M, [CAN] = 16 × 10−2 mol/L, T = 50°C, and t = 2 h. Water uptake of the PVA graft films increased with the increase of grafting yield. The imparted cyano group of the grafted PVA polymer chains (with degree of grafting up to 136%) was converted into amidoxime group by the reaction with hydroxylamine hydrochloride. The grafted polymers were characterized by FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. The grafted PVA films are more thermally stable than the ungrafted PVA membrane, because the grafted membrane showed a single degradation pattern despite having two components. A decrease in T g values is observed as the grafting yield of copolymers increases indicating the incorporation of polydiaminomaleonitrile chains in amorphous copolymers with higher thermal stability. The prepared amidoximated DAMN136- g-PVA was investigated for its properties in removing heavy toxic metals, such as Pb2+, Cd2+, Zn2+, Fe3+, Cu2+, Ni2+, and Co2+ from water. The amidoximated film is characterized by a considerably greater binding ability with respect to heavy metals. The nature of the metal ion also has great importance in the amount binding to the polymeric material. The kinetics of the sorption/desorption process for Co2+, Ni2+, and Zn2+ were investigated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

In this study, a series of poly(styrene-co-vinyl phosphonic acid) [P(S-co-VPA)] copolymers were synthesized by the free-radical copolymerization of styrene and vinyl dimethyl phosphonate followed by alkaline hydrolysis. The P(S-co-VPA) copolymers were characterized by size exclusion chromatography (gel permeation chromatography), Fourier transform infrared vibrational spectroscopy, proton nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and electrochemical impedance spectroscopy. Despite the difference between the copolymerization ratios of styrene and vinyl dimethyl phosphonate, the resulting copolymers presented single glass transitions at temperatures that depended on the acidic group amount. The glass transition shifted to a higher temperature and became broader as the amount of phosphonic acid increased. The storage modulus at temperatures higher than the glass transition also increased with increasing acidic groups because of intramolecular and intermolecular interactions. All of the acid copolymers were thermally stable to at least 300°C. A high oxidative stability was found for 3 : 1 P(S-co-VPA), which also presented conductivity values on the order of 10-6 Ω-1 cm-1 at room temperature. The 1 : 1 P(S-co-VPA) membrane presented Arrhenius-type behavior at temperatures from 30 to 80°C and conductivity on the order of 10-5 Ω-1 cm-1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

Amphiphilic block copolymers have been the subject of great scientific interests due to their applications in various fields including nano drug delivery. Three amphiphilic block copolymers based on poly(ε‐caprolactone) as a hydrophobic segment and methoxy poly(ethylene oxide) (as a hydrophilic part were synthesized by the ring‐opening polymerization of ε‐caprolactone using MeO‐PEO5K as macroinitiator by varying initial feed ratios. The synthesized polymers were further explored for their drug delivery potential using clotrimazole as model hydrophobic drug. Drug‐loaded micelles were characterized for shape, size, drug encapsulation efficiency, in vitro release, and thermal stability using atomic force microscope, zetasizer, UV–visible spectrophotometry, FTIR, differential scanning calorimetry, and thermogravimetric analysis. Clotrimazole loaded in micelles were also investigated for its antifungal activity through an in vitro assay and scanning electron microscopy. The antifungal activity of drug increased significantly by delivering through polymeric micelles. Current study provides insight into different factors that can be maneuvered to achieve a variety of desired properties of micelles for improved therapeutic efficacy of drugs like clotrimazole. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47769. [ABSTRACT FROM AUTHOR]