Adsorption of Zn(II) by crosslinked acrylic copolymers with amine functional groups

Adsorption of Zn(II) ions from diluted aqueous solutions by the acrylic copolymer based on ethylacrylate : acrylonitrile : divinylbenzene matrix with different crosslinking degrees and ethylenediamine and triethylenetetramine functional groups was investigated. Adsorption experiments were carried out by batch method. The effects of the pH, initial concentration of zinc, time of contact, and the crosslinking degree of the copolymers were studied. On the basis of Langmuir and Freundlich isotherms, the parameters that characterize the adsorption were determined. The maximum Zn(II) retention capacity value (500 mg g^?1) was obtained for the acrylic copolymer with 2% crosslinking degree and ethylenediamine, as functional groups. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 803–808, 2004     

Preparation and characterization of thermosensitive beads with macroporous structures

Thermosensitive copolymers of poly(N‐isopropyl acrylamide)‐co‐2‐hydroxyethyl methacrylate (NIPA‐co‐HEMA) macroporous resins were synthesized in the form of beads by inverse suspension polymerization. The copolymerization was carried out in aqueous solutions of the comonomers dispersed by cyclohexane with stabilizers. A series of resins with different molar ratios of NIPA : HEMA, and different crosslinking degrees was obtained. The compositions of the copolymers were determined by elemental analysis. The results showed that the content of HEMA in a copolymer was higher than that of the corresponding feed mixture from which the copolymer was made. IR spectra also confirmed the structure of the copolymers. The porous parameters such as true densities, apparent densities, pore volumes, and porosities of the resins were measured by means of pycnometry. The determination of equilibrium swelling ratios and measurement of differential scanning calibration indicated that the resins exhibited thermosensitivity in aqueous solutions. Finally, the loading of hydroxyl groups was determined by titration. The resins have potential applications as supports in solid‐phase synthesis after being functionalized. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1792–1797, 2004     

Synthesis and structure of polysiloxane liquid crystalline elastomers with a mesogenic crosslinking agent

A new mesogenic crosslinking agent M‐1 was synthesized to minimize the perturbations of a nonmesogenic crosslinking agent for liquid crystalline elastomers. The synthesis of new side‐chain liquid crystalline elastomers containing a rigid mesogenic crosslinking agent M‐1 and a nematic monomer M‐2 is described by a one‐step hydrosilylation reaction. The chemical structures of the obtained monomers and elastomers were confirmed by ¹H NMR and FTIR spectroscopy. The mesomorphic properties and phase behavior were investigated by differential scanning calorimetry, polarizing optical microscopy, and X‐ray diffraction measurements. The influence of the crosslinking units on the phase behavior is discussed. The elastomers containing less than 15 mol % of the crosslinking units showed elasticity, reversible phase transition, and nematic‐threaded texture. However, when the crosslinking density reached 21.6 mol %, the mesophase of polymer P‐8 disappears. The adoption of a mesogenic crosslinking agent diminishes the perturbation of a nonmesogenic crosslinking agent on mesophase of liquid crystalline elastomers, and isotropic temperature and a mesomorphic temperature range slightly decreased with increasing content of the crosslinking agent. In addition, X‐ray analysis shows nematic polydomain network polymers can transform into smectic monodomain by stress induction, leading to the orientation formation macroscopically. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1736–1742, 2004     

Poly(allyl glycidyl ether)‐block‐poly(ethylene oxide): A novel promising polymeric intermediate for the preparation of micellar drug delivery systems

Novel diblock copolymers designed for the preparation of micellar drug delivery systems, consisting of hydrophobic poly(allyl glycidyl ether) (PAGE) and hydrophilic poly(ethylene oxide) (PEO), were prepared, and their self‐assembly into micellar structures was studied. Copolymers differing in the length of the polymer blocks were purified and characterized. These amphiphilic copolymers with narrow molecular weight distributions were prepared through the anionic polymerization of allyl glycidyl ether with PEO monomethyl ether sodium salt as the macroinitiator. The PAGE–PEO copolymer readily formed small micelles with narrow size distributions via simple dissolution in water. The addition of pendant double bonds to the hydrophobic part of the chain was intended for further covalent modifications. Catalytic hydrogenation, the radical crosslinking of the micelle core, and the addition of thiol to double bonds of the copolymer were examples of such modifications that were proved to proceed with a quantitative yield for this copolymer. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 201–211, 2005     

Polyurethane–polyaniline conducting graft copolymer with improved mechanical properties

The crosslinking effects on the mechanical and electrical properties of a conducting copolymer obtained by grafting polyaniline on a carboxylated polyurethane were investigated. The synthesis and characterization of the polyurethane–polyaniline copolymer (PEUAPAN) were previously reported. The crosslinking process was carried out by reacting ethylenediamine with those polyurethane residual carboxylic groups not involved in the amide binding to the conducting chains. The insoluble material obtained (PEUAPANc) shows a marked elastomeric feature, as evidenced in stress–strain and stress–relaxation measurements. Although the crosslinked graft copolymer conductivity is lower than that of the pristine material, its variation during deformation cycles is reversible because the chain relaxation and viscous flow phenomena are drastically suppressed by the crosslinks. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2516–2521, 2003     

Macromolecular sorbent materials for urea capture

Three types of chitosan–glutaraldehyde (Chi–Glu) crosslinked copolymer materials were prepared at various Chi–Glu weight ratios (i.e., 1 : 0.0835, 1 : 0.334, and 1 : 0.585) and variable reaction times. The corresponding Chi–Glu copolymer materials were imbibed in CuSO₄ solution to yield impregnated materials in the form of copolymer/Cu(II) complexes. The copolymer materials were characterized using FTIR spectroscopy and thermogravimetry analysis. Urea sorption isotherms were obtained in aqueous solution at 295 K and pH 7 with pristine chitosan, Chi–Glu copolymers (i.e., 1 : 0.0835 and 1 : 0.585), and the corresponding Chi–Glu/Cu(II) complexes. The concentration of unbound urea was monitored indirectly using a colorimetric method with p‐dimethylaminobenzaldehyde. The equilibrium adsorption data were analyzed using the Sips isotherm model. The uptake of urea with pristine chitosan was 4.7% w/w, whereas Chi–Glu copolymers display increased sorption (Q_m = 10.6–17.1% w/w) with increasing glutaraldehyde content. Urea sorption is further enhanced (Q_m = 16.3–26.4% w/w) for copolymer Chi–Glu/Cu(II) complexes. The preparation of Chi–Glu copolymers at various conditions illustrates that the sorption capacity and molecular recognition of urea can be systematically tuned via crosslinking and the formation of copolymer/Cu(II) complexes, and these results are related to a previously reported study (Shimizu and Fujishige, J. Biomed. Mater. Res. 1983, 17, 597). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Shear rheological properties of acrylic copolymers and terpolymers suitable for potentially melt processable carbon fiber precursors

In an effort to generate melt processable polyacrylonitrile (PAN) precursor fibers suitable for conversion to carbon fibers, an acrylonitrile/methyl acrylate (AN/MA) copolymer and two acrylonitrile/methyl acrylate/acryloyl benzophenone (AN/MA/ABP) terpolymers were synthesized at molar ratios of 85/15 and 85/14/1, respectively. The termonomer (ABP) was incorporated to accelerate crosslinking via UV irradiation, which serves to prevent relaxation of orientation and flow as the temperature of the fiber is raised during thermooxidative stabilization. Two molecular weights of the terpolymer and one molecular weight of the copolymer were studied to determine the effect of the termonomer, and the effect of molecular weight (MW), on the steady shear viscosity (η) and magnitude of the complex viscosity (η*). A higher rate of increase of η as a function of time was observed for the high MW terpolymer relative to that of the copolymer over the temperature range used. Using a temperature sweep and monitoring levels of η*, a minimum was observed at lower temperatures for both terpolymers. These results suggest that copolymerization with ABP significantly increased the thermally induced kinetics of crosslinking. Comparison of the η and η* data for the low and high MW terpolymers suggested that molecular weight also significantly reduced the melt stability (increased the kinetics of crosslinking). A chemorhelogical correlation was then used to quantify the effects of the termonomer and of molecular weight on the kinetics of crosslinking of the AN terpolymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2856–2865, 2004     

Degree of conversion of a copolymer of an experimental monomer and methyl methacrylate for dental applications

The aim of this study was to determine the degree of double bond conversion of the copolymer of an experimental monomer and methyl methacrylate after photopolymerization. A mixture of an experimental monomer with four methacrylate groups and methyl methacrylate monomer (mass ratio 70 : 30) was polymerized by using various concentrations of light initiator system. The degree of conversion was determined with FTIR spectrometry. A photopolymerized 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloxypropoxy)‐ phenyl]propane/triethylene glycol dimethacrylate (mass ratio 40 : 60) copolymer was used as a control material for degree of conversion. The maximum degree of conversion for the experimental monomer/methyl methacrylate copolymer was 62% and was obtained with 2 wt % initiator concentration. It was comparable to that of the control polymer (64%). The results of this study suggest that the experimental monomer/methyl methacrylate system can be polymerized by light initiator system. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1908–1912, 2004     

Formation of thermosensitive water‐soluble copolymers with phosphinic acid groups and the thermosensitivity of the copolymers and copolymer/metal complexes

Thermosensitive and water‐soluble copolymers were prepared through the copolymerization of acryloyloxypropyl phosphinic acid (APPA) and N‐isopropyl acrylamide (NIPAAm). The thermosensitivity of the copolymers and copolymer/metal complexes was studied. The APPA–NIPAAm copolymers with less than 11 mol % APPA moiety had a lower critical solution temperature (LCST) of approximately 45°C, but the APPA–NIPAAm copolymers with greater than 21 mol % APPA moiety had no LCST from 25 to 55°C. The APPA–NIPAAm copolymers had a higher adsorption capacity for Sm³⁺, Nd³⁺, and La³⁺ than for Cu²⁺, Ni²⁺ and Co²⁺. The APPA–NIPAAm (10:90) copolymer/metal (Sm³⁺, Nd³⁺, or La³⁺) complexes became water‐insoluble above 45°C at pH 6–7, but the APPA–NIPAAm (10:90) copolymer/metal (Cu²⁺,Ni²⁺, or Co²⁺) complexes were water‐soluble from 25 to 55°C at pH 6–7. The temperature at which both the APPA–NIPAAm copolymers and the copolymer/metal complexes became water‐insoluble increased as the pH values of the solutions increased. The APPA–NIPAAm copolymers were able to separate metal ions from their mixed solutions when the temperature of the solutions was changed; this was followed by centrifugation of the copolymer/metal complexes after the copolymers were added to the metal solutions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 116–125, 2004     

Properties of a new synthetic rubber: High‐trans 1,4‐poly(butadiene‐co‐isoprene) rubber

A high‐trans 1,4‐butadiene/isoprene copolymer (TBIP) was synthesized in a 5‐L autoclave with hydrogen as an effective molecular weight modifier. The effects of hydrogen on the catalyst efficiency and molecular weight of the copolymers were investigated. The processability and physicomechanical properties of TBIP and their relationship to the composition, composition distribution, and molecular weight of TBIP were examined in detail. Increasing the H₂ pressure effectively reduced the molecular weight of TBIP. The optimum Mooney viscosity of TBIP and the 1,4‐butadiene molar content in the feed were 30–50 and 5–25%, respectively. No cis–trans isomerization was observed during the roll processing procedure for TBIP. The vulcanization characteristics of TBIP were similar to those of general rubbers, and no reverse vulcanization was observed for TBIP. A high green strength was the typical characteristic of TBIP. Vulcanized TBIP (TBIR) with an optimum composition and molecular weight presented outstanding antifatigue properties and low heat buildup in comparison with general rubbers. Compared with general sidewall stock [natural rubber (NR)/butadiene rubber (BR) = 50/50], TBIR exhibited a greater than 15‐fold increase in its crack‐initiation resistance. The other mechanical properties of TBIR were similar to those of 50/50 NR/BR. The heat‐aging mechanism of TBIR was crosslinking aging. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2941‐2948, 2004     

The influence of the diluent system on the porous structure formation of copolymers based on 2‐vinylpyridine and divinylbenzene. Diluent system. III. heptane/methylethylketone

The effects of the diluent mixture's composition and crosslinking degree [divinylbenzene (DVB)] on the porous characteristics of the anion‐exchange resins based on 2‐vinylpyridine (2VP) and DVB, synthesized by suspension polymerization, in the presence of a diluent mixture constituted of heptane (HEP) and methyl ethyl ketone (MEK) at different proportions, were evaluated. The resins were characterized by mercury porosimetry, nitrogen adsorption (Brunauer–Emmett–Teller (BET) method surface area determination), apparent density, and swelling in methanol. The optical appearance of the copolymer beads was examined by optical microscopy. It was found that the development of porosity was attained whenever the content of methyl ethyl ketone in the diluent mixture was increased for all DVB contents employed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 666–669, 2004     

Physical properties of ethylene vinyl acetate copolymer (EVA)/natural rubber (NR) blend based foam

In this study an attempt was made to improve the rebound resilience and to decrease the density of ethylene‐vinyl acetate copolymer (EVA) foam. For this purpose, EVA was blended with natural rubber (NR), and EVA/NR blends were foamed at 155°C, 160°C, and 165°C. To investigate the correlation between crosslinking behavior and physical properties of foams, crosslinking behavior of EVA/NR blends was monitored. The physical properties of the foams were then measured as a function of foaming temperatures and blend compositions: 165°C was found to be the optimal temperature for a crosslinking of EVA/NR foam. As a result, the density of EVA/NR blend foamed at 165°C was found to be the lowest. EVA/NR (90/10) blend, foamed at 165°C, showed lower density, better rebound resilience, and greater tear strength than EVA foam. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2212–2216, 2004     

Conducting polymers of terepthalic acid bis-(2-thiophen-3-yl-ethyl) ester and their electrochromic properties

Terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester (TATE) was synthesized through the reaction of 2-thiophen-3-yl-ethanol and terepthaloyl chloride. Homopolymer of TATE was synthesized via potentiostatic and potentiodynamic methods by using tetrabutylammonium tetrafluoroborate (TBAFB) as the supporting electrolyte in dichloromethane/borontrifluoride ethylether solvent mixture (DM/BFEE) (8:2, v/v). Copolymerisation of TATE with thiophene was achieved in DM/BFEE solvent mixture (8:2, v/v) by using TBAFB as the supporting electrolyte in the presence of thiophene. The chemical structure of monomer is characterised via NMR and FTIR. Both homopolymer (PTATE) and copolymer P(TATE-co-Th) were characterised by various techniques including cyclic voltammetry, FTIR, scanning electron microscopy and UV-VIS spectroscopy. Conductivities of samples were measured by four probe technique. Optoelectrochemical analysis indicates that the homopolymer and copolymer have an electronic band gap, measured as the onset of the π-to-π* transition, as 2.17 and 2.00 eV, respectively.     

Iodine bactericidal action adsorbed in 2‐vinylpyridine copolymer networks

In the present work, different kinds of porous copolymer networks based on 2‐vinylpyridine (2VP) and divinylbenzene (DVB) containing anchored iodine were prepared and evaluated for inactivating Escherichia coli in an aqueous medium. By using bacterial viability assays with E. coli (AB 1157, wild‐type), the iodine bactericidal effect was investigated at room temperature by elution through short columns filled with copolymer beads. Saline solutions containing bacterial cells at several contents (10² to 10⁷ cells/mL) were eluted. After each elution, cell content viability was determined by plating these suspensions on nutritive agar plates, incubating them at 37°C for 24 h, and counting as colony‐forming units (CFUs). It was verified that the networks containing anchored iodine were completely bactericidal within a few minutes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 972–976, 2004     

Synthesis and characterization of partially crosslinked poly(N-vinylcarbazole-vinylalcohol) copolymers with polypyridyl Ru(II) luminophores: Potential materials for electroluminescence

Summary A novel difunctionalized 5,5'-dibromomethylene-2,2' bipyridine ligand was prepared and covalently bound with concurrent crosslinking by a post-polymer modification method to (N-vinylcarbazole-vinylalcohol) copolymer. The electrochemistry and UV-vis spectroscopy results both confirm the covalent attachment of ruthenium transition metal complex to the polymer backbone. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) indicate high thermal stability of the copolymer. The copolymer is also highly phosphorescent making it a potential polymeric material for transition metal based electroluminescent devices. Received: 1 November 1998/Revised version: 18 August 1999/Accepted: 18 August 1999     

Synthesis and properties of thermoplastic expandable microspheres: The relation between crosslinking density and expandable property

A set of thermoplastic expandable microspheres was investigated with respect to their crosslinking density and expandable property. The crosslinking efficiencies of dipentaerythritol hexaacrylate in a set of thermoplastic expandable microspheres were measured. As expandable properties, expansion curves were measured by using a thermomechanical analyzer, and they also were shown by measuring the change of thickness of the coated compound consisting of ethylene–vinyl acetate copolymer resin emulsion and CaCO₃ with thermoplastic microspheres on paper. In view of the expansion ratio and heat resistance, as crosslinking density, a swelling ratio of about 20–25 is needed to achieve optimum expansion without collapse and rupture of microspheres. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 505–512, 2004     

共聚原甲基丙烯酸酯系吸附功能树脂合成及其性能研究

采用悬浮聚合法合成了LMA(甲基丙烯酸十二酯)均聚树脂、BMA(甲基丙烯酸正丁酯)/LMA共聚树脂、BMA/HEMA(甲基丙烯酸( 羟乙酯)共聚树脂、BMA/DVB(二乙烯基苯)共聚树脂以及BMA/HEMA/LMA共聚树脂.研究了单体种类、交联剂种类以及用量与树脂吸附性能、交联密度间的关系,利用FT-IR对树脂试样的化学结构进行了表征.结果表明,与LMA均聚物相比,BMA被引入大分子主链后,BMA/LMA共聚树脂对煤油的吸附量大大降低,对甲苯和三氯乙烯的吸附量增大,而BMA/LMA/HEMA共聚树脂对煤油、甲苯和三氯乙烯的吸附量均有所下降;化学交联型树脂的吸附量随时间变化较小,物理交联型树脂其吸附量随时间变化较为明显;物理交联剂HEMA的质量分数影响树脂的三维网状结构,进而影响树脂的吸附性能;树脂大分子间存在氢键作用,有利于物理交联结构的形成,长侧链LMA结构单元的引入,促使侧链间发生缠结甚至结晶,进一步增强了物理交联结构.     

Synthesis and characterization of reactive macroporous poly(glycidyl methacrylate‐triallyl isocyanurate‐ethylene glycol dimethacrylate) microspheres by suspension polymerization: Effect of synthesis variables on surface area and porosity

A novel macroporous poly(glycidyl methacrylate‐triallyl isocyanurate‐ethyleneglycol dimethacrylate) copolymer, hereinafter P_{GMA‐TAIC‐EGDMA}, of controlled bead size was prepared via free radical suspension copolymerization. The effects of varying the concentration of crosslinking agents and porogenic diluent on the average pore diameter, pore size distributions, specific surface area, and pore volume of the copolymer matrix were thoroughly investigated. The spherical beads were characterized by elemental analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The specific pore volume, average pore diameter, pore size distribution, and the specific surface area were measured by Mercury intrusion porosimetry and BET adsorption method, respectively. The porous properties of the polymer matrix are a direct consequence of the amount and quality of the porogenic solvent, the percentage of crosslinking monomers, and the ratio between the monomers and porogen phases. When the polymer was prepared at 30 and 40% crosslinking density, and 75 and 100% diluents, respectively, it showed a fine beads morphology, mechanical stability and pore size distributions. By comparing the copolymers P_{GMA‐TAIC‐EGDMA} and P_GMA‐EGDMA, it was found that the former is more stable both thermally and mechanically than its predecessor. The presence of epoxide functionalities of macroporous P_{GMA‐TAIC‐EGDMA} beads makes it a versatile carrier. The resulting polymers have the potential for wide applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of PEI nanofiber membrane based on in situ and solution crosslinking technology and their adsorption properties

Two kinds of PEI (Polyethyleneimine) nanofibers membrane were successfully prepared by electrospinning and crosslinking technology, which were insoluble in water. One Polyethyleneimine/ Epichlorohydrin/ Polyacrylonitrile nanofibrous films (abbreviated as PEI/ EPI/ PAN NFs) was prepared by in situ crosslinking of PEI/PAN nanofiber containing of EPI, and the other PEI/ PAN/ EPI NFs was prepared by crosslinking PEI/ PAN nanofibers using EPI solution. The composition and morphology of nanofibers before and after crosslinking were investigated by infrared spectroscopy and scanning electron microscopy. PEI/EPI/PAN nanofibers exhibited excellent adsorption properties toward heavy metal ions and methyl orange dyes, which can also be reused multiple times. The adsorption rate of methyl orange remained around 75% after 4 cycles, meanwhile, the adsorption rate of copper and lead still remained around 90% after 5 cycles. In addition, we found that PEI/ PAN/ EPI nanofibers prepared by solution crosslinking technology solved the problem of easy gel formation in in situ crosslinking technology and facilitated the continuous production of PEI/ EPI/ PAN nanofibers, which is better than in situ crosslinking technology. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48279.     

Electrochemical polymerization of fluoro‐ and chloro‐substituted anilines and copolymers with aniline

Poly(2‐fluroaniline) and poly(2‐chloroaniline) were synthesized by an electrochemical method in an acetonitrile solution containing tetrabutylammonium perchlorate and perchloric acid. Also, the electrochemical copolymerization of aniline with 2‐fluroaniline and 2‐chloroaniline was carried out in the same medium. Cyclic voltammograms of the deposited films were recorded in neutral, acidic, and basic solutions. The electrochemical behavior of the films showed the same characteristic results as conventional polyaniline. The observed decrease in the dry electrical conductivity of the copolymers with respect to polyaniline was attributed to the incorporation of the fluoro‐ and chloro‐substituted anilines into the polyaniline chain. Further characterization of the polymer and copolymer products was performed through dry electrical conductivity measurements, ultraviolet–visible spectroscopy, and Fourier transform infrared spectroscopy. The relative solubility of the films was determined in various common organic solvents. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2302–2312, 2004