Adsorption behavior of cocamidopropyl betaine under conditions of high temperature and high salinity

The adsorption behavior of cocamidopropyl betaine (CAB) in aqueous solutions and on sandstone surfaces was studied under the conditions of high temperature and high salinity. In aqueous solutions, as temperature increased from 25 to 90°C and salinity increased from 0 to 115,200 ppm, surface tension and the critical micelle concentration (cmc) of CAB both decreased. In the solid/liquid system, when the CAB concentration of salt solutions reached 0.30 wt %, the static saturation adsorption amount on the surface of clean sands was 14.77 mg g^?1 at 90°C. Because of its noticeable saturation adsorption capacity, the adsorption of CAB on the solid/liquid interface agreed with multilayer adsorption. Also, the adsorption amount on the surface of oil sands was greater than on clean sands. Besides, the dynamic saturation adsorption amount and retention amount of 0.07 wt % CAB solution were less than the static adsorption amount. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40424.     

Facile fabrication of superhydrophobic polyaniline structures and their anticorrosive properties

We report a simple approach for the preparation of superhydrophobic polyaniline (PANI) and its application for the corrosion protection coatings. First, PANI was synthesized conventionally by oxidative polymerization with APS. Subsequently, PANI with different wettability was obtained by modification with different surfactants. The surface modification of PANI with three different surfactants (sodium dodecylbenzenesulfonate, polyethylene glycol, and cetyltrimethylammonium bromide) provided excellent surface superhydrophobicity (water contact angle >150°). The structure and morphology of as‐prepared PANI were characterized with Fourier transform infrared, Energy dispersive X‐ray spectroscopy, and Scanning electron microscopy. Corrosion protection performance of PANI with different wettability was evaluated in 3.5% NaCl electrolyte using Tafel polarization curves and electrochemical impedance spectroscopy. The results indicated that various superhydrophobic PANI coatings have better anticorrosion performance as compared to the hydrophilic PANI. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44248.     

Synthesis and properties of new water‐soluble copolymers based on methyl acrylic acid sucrose ester and methyl acrylic acid

The new series of copolymers were obtained based on free radical solution copolymerization by mixing self‐made methyl acrylic acid sucrose ester (MASE) and methyl acrylic acid (MAA) with different ratios. Copolymerization behavior and properties of the new copolymers was investigated with the reaction time, temperature, monomer ratios and characterized by Fourier transform infrared spectra (FT‐IR), carbon nuclear magnetic resonance (¹³C NMR), and intrinsic viscosity. The results indicated that sucrose was successfully grafted onto poly (methyl acrylic acid). Further, it was demonstrated that low temperature benefited the esterification of MASE. Importantly, the copolymers were founded to have good compatibility with polymethyl methacrylate (PMMA), polytetrafluoroethylene (PTFE), and polyethylene (PE). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43627.     

The effect of modifier contents of polyvinyl pyrrolidone on the enhanced dielectric and microwave absorbing properties of multiwalled carbon nanotubes

Polyvinyl pyrrolidone (PVP) polymers were used as non‐covalent modifiers to modify the surface of multi‐walled carbon nanotubes (MWNTs) by ultrasonic dispersion method. The transmission electron microscope results suggest that a layer of polymers is wrapped on the surface of MWNTs, and the thickness is about 2.5 nm. The addition of PVP helps to facilitate uniform distribution of MWNTs and increases the interfacial multipoles formed between PVP and MWNTs, which plays an important role in the regulation of the dielectric parameter and the enhancement of the microwave absorbing properties. The effects of PVP loadings and thickness of PVP/MWNTs hybrids on the dielectric parameter of MWNTs are investigated. The microwave absorbing properties are calculated from the dielectric constants. The results show that the maximum reflection loss is ?26.27 dB at 7.8 GHz while the loading of PVP on MWNTs is 8.0 wt % with a thickness of 3.0 mm. These results suggest that the PVP contents and absorber thickness are important factors for the improvement of dielectric loss and microwave absorption properties of MWNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41007.     

Study of effect of two sulfonating agents on electrochemical properties of surface-modified polyethersulfone membrane

The work deals with the selection of sulfonating agent and preparation of polymeric coating on membrane step by step. The surface modification of a commercial ultrafiltration polyethersulfone (PES) membrane was covalently attached to the poly(styrene-co-divinylbenzene-co-4-vinylbenzylchloride). The whole process was tracked step by step using analytical methods. Chlorosulfonic acid and trimethylsilyl chlorosulfonate were tested as sulfonating agents. Ion-exchange capacity (IEC), water content, specific resistance, and permselectivity were measured and scanning electron microscope analyzed the surface of the cation exchange membrane. The best results were achieved using 5 wt % chlorosulfonic acid as sulfonating agent. IEC reached values of up to 2.44 meq g⁻¹ of dry matter, permselectivity of 93.6%, area resistances of 10.1 Ω cm², and specific resistance around 299 Ω cm. The prepared cation exchange PES membrane with chlorosulfonic acid can be used in electrochemical processes, for example, in electrodialysis. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48826.     

Microstructure and properties of carbon fiber sized with pickering emulsion based on graphene oxide sheets and its composite with epoxy resin

The Graphene oxide (GO) sheets were used for preparing the epoxy resin Pickering emulsion. The particle size and the zeta potential of the Pickering emulsion were measured to evaluate its stability. The stable emulsion could be served as the film former of sizing agent for carbon fiber (CF). The effect of the Pickering emulsion stabilized by GO sheets on the properties of CF and the interfacial adhesion property of CF reinforced composite were investigated. Scanning electron microscopy (SEM) images showed that there existed a layer of sizing agent film with GO sheets evenly on the CF surface. Abrasion resistance and stiffness values of CF were tested and the results indicated that the sized CF conformed to the requirement of CF handleability. The interlaminar shear strength (ILSS) test indicated that the interfacial adhesion of the composite could be greatly improved. The fracture surfaces of CF composites were examined by SEM after ILSS tests. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42285.     

Novel comb-like anion-nonionic copolymer for improving the stability of pymetrozine suspension concentrate

Coalescence and flocculation are two challenges for the stability and efficacy of pesticide suspension concentrate (SC) during the production and storage. To improve the stability of 25% pymetrozine SC, three comb-like poly(styrene-co-acrylic acid-co-polyethylene glycol methyl ether maleate) (SA-M) with different length side chains were synthesized by free radical polymerization and characterized by Fourier transform infrared spectroscopy and H-nuclear magnetic resonance. Surface-active parameters, including critical aggregation concentration (critical micelle concentration), saturation surface excess concentration (Γ_max), minimum area per molecule (A_min), and standard Gibbs free energy values were obtained from surface tension measurement. It shows that the surface-active property of SA-M decreased with the side chain length. Besides, 25% pymetrozine SC prepared using SA-M as dispersant had low zeta potential and low viscosity but high dispersibility and thermal storage stability. It is speculated that the formation of hydrogen bonds between nonionic branches and pymetrozine molecule at the expense of interruption of intermolecular hydrogen bonding between pymetrozine and water molecule, plays a key role in the stability mechanism.     

Interlayer bonding between thermoplastic composites and metals by in-situ polymerization technique

Fiber-metal laminates (FMLs) offer the superior characteristics of polymer composites (i.e., light weight, high strength and stiffness) with the ductility and fracture strength of metals. The bond strength between the two dissimilar materials, composite and metal, dictates the properties and performance of the FMLs. The bonding becomes more critical when the polymer matrix is thermoplastic and hydrophobic in nature. This work employed a novel bonding technique between thermoplastic composites and a metal layer using six different combinations of organic coatings. The flexural, and interlaminar shear strength of the thermoplastic fiber metal laminates (TP-FMLs) were examined to investigate the bond strengths in the different cases along with fracture characteristics revealed from the tested samples using scanning electron microscopy. The viscoelastic performance of the fabricated TP-FMLs were also investigated using the dynamic mechanical thermal analysis method.     

Experimental study of the effect of zeolite 4A treated with magnesium hydroxide on the characteristics and gas‐permeation properties of polysulfone‐based mixed‐matrix membranes

Nowadays, new methods for gas‐separation processes are being quickly developed. The separation of CH₄/CO₂ and CH₄/H₂ is usually the subject of most related research studies, especially in the membrane gas‐separation process, because of their important role in industry. In this study, we attempted to improve the separation properties of a polysulfone/zeolite 4A mixed‐matrix membrane by modifying the zeolite particle surface. The method included a simple ion‐exchange reaction of magnesium chloride with ammonium hydroxide that yielded the formation and precipitation of magnesium hydroxide whiskers on the surface of the zeolites. The whiskers could omit most of the nonselective voids by interlocking the polymer chains through them and, consequently, improve the permeability, selectivity, and elastic modulus of the membranes. X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and dynamic mechanical analysis proved all the changes recorded after the particle and membrane treatments. SEM images showed the petal‐like morphology of the whiskers that formed on the surface of the particles after the reaction against the smooth surface of the untreated zeolite. At a 30 wt % loading of particles in the polymeric matrix, the selectivities for H₂/CH₄ and CO₂/CH₄ increased by 69 and 56%, respectively; in contrast, the H₂ and CO₂ permeabilities decreased by 2.5 and 10%, respectively. The modulus of elasticity for the treated membrane also increased by 14 and 30% compared to those of the pure and untreated membranes, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44329.     

Preparation of hybrid composite microspheres containing nanosilicon via microsuspension polymerization

Hybrid composite microspheres with nano‐Si as the core and poly(styrene‐co‐acrylonitrile) as a shell are successfully prepared by a two‐step polymerization technique, which includes dispersion polymerization of styrene and 3‐methacryloxypropyl trimethoxysilane in ethanol for surface modification of nano‐Si followed by microsuspension polymerization of styrene and acrylonitrile in an aqueous phase for encapsulating nano‐Si into an SAN copolymer matrix. The structure and surface properties of modified nano‐Si are investigated by Fourier transform infrared spectroscopy (FTIR) and contact angle. The hybrid composite microspheres are systematically characterized by energy dispersive spectroscopy, thermogravimetric analysis, and transmission electron microscopy (TEM). According to the FTIR spectra and the contact angle experiments, it was determined that a hydrophobic polymer layer was formed on the surface of nano‐Si. TEM showed that nano‐Si was homogeneously dispersed in SAN particles when the loading capacity of nano‐Si in the hybrid composite microspheres was less than 20 wt %. Moreover, scanning electron microscopy and X‐ray photoelectron spectroscopy revealed that there were large amounts of nano‐Si absorbed on the surface of the hybrid composite microspheres, and the mean particle size became much larger when the loading amounts of nano‐Si reached 25 wt %. From this, it can be inferred that nano‐Si overflows from the inner core to the outside surface in the emulsification process and acts as an inorganic dispersant. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43101.     

Influence of polymer on dynamic interfacial tensions of EOR surfactant solutions

The effects of different types of polymers, partially hydrolyzed polyacrylamide (HPAM) and hydrophobically modified polyacrylamide (HMPAM), on dynamic interfacial tensions (IFTs) of surfactant/model oil systems have been investigated by the spinning drop method in this article. Two anionic surfactants, 1,2‐dihexyl‐4‐propylbenzene sulfonate (366), 1,4‐dibutyl‐2‐nonylbenzene sulfonate (494) and an anionic–nonionic surfactant octyl‐[ω‐alkyloxy‐poly(oxyethylene)]yl‐benzene sulfonates (828) with high purity were selected as model surfactants. The influences of polymer concentration on IFT were expounded. It was found that the addition of polymer mostly results in increasing IFT because the interfacial molecular arrangement is modified owing to the interaction between polymer and surfactants. For HPAM, the polymer chains will enter the surfactant adsorption layer to form mixed‐adsorption layer. Therefore, HPAM shows strong effect on surfactant molecules with large size, such as 366. Conversely, surfactants can interact with the hydrophobic blocks of HMPAM and form mixed micelle‐like associations at interface. As a result, HMPAM shows more impact on IFT of 494 due to small steric hindrance for the formation of interfacial associations. This mechanism has been ensured by 828 molecules with two long alkyl chains. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40562.     

Synthesis of walnut-like polyaniline by using polyvinyl alcohol micellar template with excellent film transmission

Though there have been many reports on various morphologies of polyaniline (PANI), the research on fabricating new morphologies remains to be explored. In this work, with the help of polyvinyl alcohol (PVA) micelles as templates, walnut-like PANI having a rough periphery is successfully synthesized at room temperature by a static reaction. In addition, the effects of the amount of PVA, the concentration of HCl solution and the type of surfactant on the morphologies of PANI are studied in detail. Outcomes demonstrate that the fabrication of PANI walnuts is a result of the cooperation effect of the amount of PVA and the concentration of HCl solution. Moreover, PANI walnuts exhibit good thermal stability, which begins to degrade at up to about 300°C. Thin film coated by PANI walnuts possesses excellent transmittance. When PANI sample is prepared in the presence of 0.50 g PVA and 0.010 M HCl solution, the film transmittance can reach a maximum of 74% at 1200 nm. The sample presented herein have potential to be used in optical devices.     

Influence of the degree of crosslinking on the stringiness of crosslinked polyacrylic pressure‐sensitive adhesives

The stringiness of crosslinked polyacrylic pressure‐sensitive adhesive (PSA) was observed during 90° peeling under the constant peel load. The random copolymer of butyl acrylate with 5 wt % acrylic acid crosslinked by N,N,N′,N′‐tetraglycidyl‐m‐xylenediamine was used as PSA. All observed stringiness upon peeling was sawtooth‐shaped, but it could be classified into three types dependent on the degree of crosslinking. The typical sawtooth‐shaped stringiness with interfacial failure was observed at the relatively higher crosslinker content ranging from 0.008 to 0.016 chemical equivalents (Eq.), where the PSA has high cohesive strength and low interfacial adhesion. The frame formed at the front end of stringiness at the content ranging from 0.002 to 0.004 Eq. Sufficient interfacial adhesion and deformability generate large internal deformation of the PSA layer. Internal deformation occurred preferentially over peeling as a result of front frame formation. The mode of peeling was changed from cohesive failure to interfacial failure in this range of crosslinker content. The sawtooth‐shaped with cohesive failure was observed at the lower content ranging from 0 to 0.001 Eq. The PSA has high interfacial adhesion and low cohesive strength, and thus exhibited cohesive failure. The PSA after peeling remained in the shape of belts. It was found that the shape of stringiness is strongly dependent on the balance between the interfacial adhesion and the cohesive strength of PSA. When the sawtooth‐shaped stringiness with frame formed, the peeling rate was lowest. This means the peel strength should be the maximum in this shape of stringiness. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40336.     

Wear‐resistant cotton fabrics modified by PU coatings prepared via mist polymerization

Cotton fabric was successfully modified using a simple mist polymerization with polyurethane (PU) prepolymer and ethylene glycol as the monomers. Scanning electron microscope showed the presence of a very thin polymer coating on the cotton fiber surface. Martindale abrasion tests revealed that the thin PU coating imparted to the cotton fabric a doubled wearing durability compared with the original fabric. Additional experiments demonstrated that the mist polymerization has little impact on the desired cotton properties such as water absorptivity, vapor transmissibility, mechanical property, and flexibility. Considering the excellent balance between the enhanced abrasion resistance and the cotton natures, this surface modification methodology has potential to fabricate wearing durable textiles. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43024.     

Promoting the dispersibility of silica and interfacial strength of rubber/silica composites prepared by latex compounding

The dispersibility of precipitated silica and its interfacial interaction with rubber matrix can affect the performances of tires which is a difficult problem to be solved. A well-dispersed silica dispersion was obtained through ball milling and modification process followed by heat treatment to enhance the properties of NR composites prepared by latex compounding. Benefiting from the modifier Si-747, the well-dispersed silica/NR composite (Silica-MSH-C) shows excellent tensile strength of 30.8 ± 0.5 MPa, which is 17.6 ± 3.8% higher than latex compounding pure silica/NR composite (Silica-C) and 21.7 ± 4.3% higher than traditional mechanical blending pure silica/NR composite (T-Silica-C). The tan delta values indicate that Silica-MSH-C has better dynamic properties and also has stronger interface strength according to swelling tests, heat capacity curves and Mooney-Rivlin equation. The molecular dynamics (MD) simulation further shows the binding energy between NR and Si-747 modified SiO₂ is 58.88 Kcal/mol larger than the value of NR and pure silica.     

聚甘油脂肪酸酯的表面性能研究

利用甘油聚合得到聚甘油,与一系列高级脂肪酸酯化合成聚甘油脂肪酸酯。分别测试和比较了合成产品的HLB值、表面张力、乳化性能、泡沫性能及钙皂分散性能,并讨论了合成影响因素,为研究聚甘油酯类产品应用性能提供了理论基础。     

Influence of surface properties on the dip coating behavior of hollow fiber membranes

Coating processes have become an important fabrication step in membrane production, either to form a separation layer on a porous substrate or to tune specific properties. The coating procedure depends to a large extent on the membrane properties which substantially impedes a prediction of the coating thickness. To give an insight into the coating properties of various hollow fiber membranes, a selection of membranes with different pore sizes was coated with aqueous poly(vinyl alcohol) solutions at various coating velocities. It was found that material properties and pore sizes of the membranes have great influence on coating thicknesses. An intrusion of coating material into the membrane structure was determined with increasing pore size. Pure intrusion without formation of a dense surface layer took place when using a membrane with a mean pore size of ca. 500 nm. Coating results were correlated with the theoretical LLD law and for some membranes the coating thickness can be predicted quite well by the LLD law and its enhancements. When a significant amount of coating material penetrated into the membrane structure the LLD law loses its validity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46163.     

The effect of high temperature annealing process on crystallization process of polypropylene,mechanical properties,and surface quality of plastic parts

This work studied the effects and action mechanism of high‐temperature annealing process parameters, such as annealing temperature, annealing duration and cooling speed, on the microstructural evolution of polypropylene (PP) on different thickness layers, the surface quality, and mechanical properties of PP plastic parts. The results show that when the PP plastic parts are annealed at slightly higher than 100°C, the resin on the surface and internal layers of plastic parts just generates the relaxation and rearrangement at the molecular level. Only at an enough high annealing temperature, the secondary crystallization and phase transformation process can be observed. The crystallinity of all annealed samples is higher than that of unannealed samples, but the crystallinity is decreased with the increase of cooling speed after annealing duration, and the annealing duration exceeding 60 min almost has no effect on the crystallinity. The microstructural change of PP on the internal layer of plastic parts is weaker than that on the surface layer. The surface hardness of the plastic parts mainly depends on the crystallinity of the surface layer, whereas the surface roughness of the plastic parts depends on not only the crystallinity, but also the space conformation of molecular chains and the residual stress. With the change of annealing process parameters, the tensile and impact strengths of plastic parts show a non‐monotonic change law. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42773.     

Improvement of interfacial adhesion between PBO fibers and cyanate ester matrix

Poly(p‐phenylene benzobisoxazole) (PBO) fibers were activated by the horseradish peroxidases (HRP) and then treated by 3‐Glycidoxypropyltrimethoxysilane (KH‐560) to improve the wettability and the interfacial adhesion between PBO fibers and cyanate ester matrix. The chemical compositions of PBO fibers were characterized and analyzed by FTIR and XPS. Surface morphologies of PBO fibers were examined by SEM. The wettability of PBO fibers was evaluated by the dynamic contact angle analysis test. The mechanical properties were evaluated by tensile strength and interfacial shear strength, respectively. The results demonstrated that hydroxyl groups and epoxy groups were introduced onto the surface of PBO fibers during the treatments. These treatments can effectively improve the wettability and adhesion of PBO fibers. The surface free energy of PBO fibers was increased from 31.1 mN/m to 55.2 mN/m, and the interfacial adhesion between PBO fiber and cyanate ester resin was improved to 10.77 MPa. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40204.     

Nanocomposite structure depending on the degree of surface treatment of layered silicate

Nanocomposite structures depending on the degree of surface modification of montmorillonite (MMT) were studied. To change the degree of surface modification, MMT was treated with a controlled amount of stearylamine. The structures of MMTs and nanocomposites were investigated by X‐ray diffraction. To confirm the extent of surface coverage of the stearylamine as a organophilic modifier, TGA and elemental analysis experiments were performed. Different structures (intercalated or exfoliated) of a polymer/clay nanocomposite were obtained according to the interfacial characteristics between the polymer chains and the clay by controlling the degree of surface coverage. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2143–2147, 2002