Synthesis and simple method of estimating macroporosity of methyl methacrylate–divinylbenzene copolymer beads

Macroporous methyl methacrylate–divinylbenzene copolymer beads having diameter ～ 300 μm were synthesized by free radical suspension copolymerization. The macroporosity was generated by diluting the monomers with inert organic liquid diluents. The macroporosity was varied in the range of ～0.1 to ～ 1.0 mL/g by varying a number of porosity controlling factors, such as the diluents, solvent to nonsolvent mixing ratios when employing a mixture of the two diluents, degree of dilution, and crosslinkage. Increase in pore volume from 0.1 to 0.45 mL/g resulted in a sharp increase in mesopores having diameters in the range of 3–20 nm whereas the macropores remained negligible when compared with mesopores. Increase in pore volume from 0.45 to 1 mL/g resulted in a sharp increase in macropores, whereas mesopores having diameters in the range of 3–20 nm remained almost constant. The mesopores having diameters in the range of 20–50 nm showed an increase with the increase in pore volume throughout the whole range of pore volume studied. Macroporosity characteristics, i.e., pore volume (V_m), surface area (SA), and pore size distributions were evaluated by mercury penetration method. Statistical analysis of the data obtained in the present study shows that the macroporosity characteristics can be estimated with a reasonable accuracy from the pore volumes, which in turn are determined from the densities of the copolymers. These results are explained on the basis of pore formation mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and metal ion adsorption studies of chelating resins derived from macroporous glycidyl methacrylate‐divinylbenzene copolymer beads anchored schiff bases

Two novel chelating resins are prepared by anchoring diethylenetriamine bis‐ and mono‐furaldehyde Schiff bases onto the macroporous GMA‐DVB copolymer beads and utilized for the adsorption towards Cu(II), Co(II), Ni(II), and Zn(II). FTIR spectra show that Schiff base groups have been successfully introduced into the polymer matrix and the chelating resins can form complexes with the metal ions. The chelating resins show a higher adsorption capacity toward Cu(II). The conductivity method can be used for determining the adsorption kinetics of the resins towards metal ions. The results show that the adsorption rates towards Cu(II) are much higher than those towards other ions and pseudo second‐order and intraparticle diffusion models can be applied to treat the adsorption amount‐time data. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Porous maleic anhydride–styrene–divinylbenzene copolymer beads

The formation of the porosity and the pore stability in maleic anhydride–styrene–divinylbenzene (MAn–St–DVB) copolymer beads were investigated using the apparent density measurements of the samples dried from methanol (maximum porosity) and from dioxane (stable porosity). The copolymer beads were prepared by the suspension polymerization method in glycerol instead of water as the dispersing medium. A toluene–dioxane (1:1) mixture was used as the diluent at a fixed volume fraction of the organic phase (0.47). Compared to St–DVB copolymers prepared in the presence of nonsolvating diluents, porous MAn–St–DVB copolymers are obtained at relatively low DVB concentration, i.e., at 1–3% DVB. The porosity of the copolymers increases with decreasing MAn concentration in the feed due to the decrease in the copolymer yield. The results of the elemental analyses and titrimetric methods indicate that approximately only half of the MAn units in the copolymer are able to react with amine or with water. A possible rearrangement of the MAn units into the cyclopentanone structures was suggested.     

Toughening of polylactide with epoxy‐functionalized methyl methacrylate–butadiene copolymer

Glycidyl methacrylate‐functionalized methyl methacrylate–butadiene (MB‐g‐GMA) copolymers were prepared via an emulsion polymerization process. These functionalized copolymers were blended with polylactide (PLA). Dynamic mechanical analysis and differential scanning calorimetry results showed that the addition of MB‐g‐GMA did not result in a marked change in the glass transition temperature of PLA. With an increase of MB‐g‐GMA content, the tensile strength of the blends decreased; however, the elongation at break and impact strength increased significantly. From scanning electron micrographs, there was large plastic deformation (shear yielding) in blends subjected to impact tests, which was an important energy‐dissipation process and led to a toughened polymer. Rheological investigation demonstrated that there was a significant dependence of viscosity on composition. When the MB‐g‐GMA content increased, the viscosity began to increase. © 2013 Society of Chemical Industry     

Synthesis and characterization of composites with sulfonated styrene‐divinylbenzene copolymer

In this work light sulfonation was applied to a styrene copolymer crosslinked with divinylbenzene (PS‐co‐DVB). Subsequently the product was incorporated at different concentrations into poly(vinylidene fluoride) (PVDF) and ethylene‐propylene‐diene (EPDM). Also, antimonic acid (HSb) was added. The resulting composites were characterized both microstructurally and electrically. In addition, PVDF/PS‐co‐DVBSH/HSb and EPDM/PS‐co‐DVBSH/HSb membranes were sulfonated, utilizing chlorosulfonic acid as a reagent, and characterized electrically. The membranes obtained by this procedure show good properties from an electric point of view.     

Alkaline hydrolysis of ethyl acrylate–acrylonitrile–divinylbenzene copolymer beads

This article deals with the alkaline hydrolysis of ethyl acrylate–acrylonitrile–divinylbenzene copolymer beads. Chemical changes during hydrolysis were evaluated by means of determination of total weight exchange capacity and of infrared spectroscopy. The influence of reaction temperature, concentration of the hydrolytic agent, degree of copolymers crosslinking as well as the influence of particle size upon the rate of hydrolysis were studied as a function of time. The mathematical and statistical calculations of experimental data were carried out. With respect to time dependence of hydrolysis of the copolymer functional groups, the average values of reaction rate constants as well as the values of assumed diffusion coefficients were calculated. The analysis is based on partial linearization of experimental results by means of semilogarithmic transformation. The empirical relations expressing dependences of reaction rate constants and of diffusion coefficients on conditions of hydrolysis were determined.     

Fe2+ and Fe3+ adsorption on 2‐vinylpyridine–divinylbenzene copolymers and acrylonitrile–methyl methacrylate–divinylbenzene terpolymers

The adsorption of Fe²⁺ and Fe³⁺ ions on 2‐vinylpyridine–divinylbenzene copolymer and acrylonitrile–methyl methacrylate–divinylbenzene terpolymer was investigated. In general, the adsorption of Fe²⁺ and Fe³⁺ in both resins increased with the enhancement of hydrochloric acid and metal concentration. The metal adsorption on the terpolymer increased sharply with the addition of small portions of ethanol, whereas the adsorption on the copolymer practically was not affected by the presence of the alcohol. An increase in temperature produced a small increase in iron adsorption for both resins. Fourier transform infrared spectra showed that nitrile and ester groups of the terpolymer did not suffer hydrolysis during metal adsorption, even for the highest HCl concentration and the highest temperature applied. A mechanism of iron adsorption through the ion exchange of chloride anions by tetrahedral [FeCl₄]^2? or [FeCl₄]^? anions is proposed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3905–3912, 2003     

Preparation of the fine powdery copolymer of glycidyl methacrylate–divinylbenzene and its application as a pigment

In order to prepare the functional and fine powdery polymer, glycidyl methacrylate (GMA) and divinylbenzene (DVB) were polymerized in cyclohexane. This polymerization was heterogeneous. In the time–conversion curve, an autoaccelerating phenomenon and an apparently steady state were observed, and the activation energies for both reactions in the earlier stage and the steady state were calculated to be 28 kcal/mole and 11 kcal/mole, respectively. It is especially noteworthy that the increase in the DVB concentration decreased the polymerization rate. The diffusion of the monomers through the polymer matrix should be one of the most important factors. Some properties of the copolymer and its application as a mordant were studied.     

Solution properties of methyl methacrylate–acrylonitrile copolymers

Characterization of methyl methacrylate-acrylonitrile copolymers is done through viscosity, swelling, and differential refractometric studies. Viscosities of the copolymers and homopolymers were determined at 30, 40, and 50°C. The activation parameters of viscous flow, voluminosity, and shape factor were also calculated. The average shape factor was observed to be 2.5 ± 0.005 for all copolymer systems. Viscosity molecular weights were calculated, and from intramolecular expansion factor (α), it was observed that copolymers are less flexible than are homopolymers. dn/dc values obtained from differential refractometry are in good agreement with those calculated theoretically. © 1993 John Wiley & Sons, Inc.     

Synthesis and properties of uniform beads based on macroporous copolymer glycidyl methacrylate–ethylene dimethacrylate: A way to improve separation media for HPLC

Monodisperse beads based on hydrolyzed macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate) for use as size-exclusion HPLC packings were synthesized by the method of “activated” swelling of polystyrene seeds followed by a suspension polymerization of both methacrylates. Effects of the type and fraction of the swelling agent, inert porogenic solvent, and cross-linking monomer on the uniformity of the particles, extent of the specific surface area, pore volume, pore size, and pore-size distribution and chromatographic properties (size-exclusion limit and column effciency) have been investigated. Trends leading to the synthesis of macroporous particles with predesigned properties for use in size-exclusion high-performance liquid chromatography in both aqueous and organic mobile phase were studied. © 1992 John Wiley & Sons, Inc.     

Thermooxidative degradation of methyl methacrylate‐graft‐natural rubber

The thermooxidative degradation of methyl methacrylate‐graft‐natural rubber (MG) at different heating rates (B) has been studied with thermogravimetric analysis in an air environment. The results indicate that the thermooxidative degradation of MG in air is a one‐step reaction. The degradation temperatures increase with B. The initial degradation temperature (T_o) is 0.697B + 350.7; the temperature at the maximum degradation rate, that is, the peak temperature on a differential thermogravimetry curve (T_p), is 0.755B + 368.8; and the final degradation temperature (T_f) is 1.016B + 497.4. The degradation rates at T_p and T_f are not affected by B, and their average values are 46.7 and 99.7%, respectively. The maximum thermooxidative degradation reaction rate, that is, the peak height on a differential thermogravimetry curve (R_p), increases with B. The relationship between B and R_p is R_p = 2.12B + 7.28. The thermooxidative degradation kinetic parameters are calculated with the Doyle model. The reaction energy (E) and frequency factor (A) change with an increasing reaction degree, and the variational trends of the two kinetic parameters are similar. The values of E and A increase remarkably during the initial stage of the reaction, then keep relevantly steady, and finally reach a peak during the last stage. The velocity constants of the thermooxidative degradation vary with the reaction degree and increase with the reaction temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1227–1232, 2003     

Thermogravimetric analysis of methyl methacrylate‐graft‐natural rubber

The thermal degradations of methyl methacrylate‐graft‐natural rubber (MG) at different heating rates (B) in nitrogen were studied by thermogravimetric analysis. The results indicate that the thermal degradation of MG in nitrogen is a one‐step reaction. The degradation temperatures increase along with the increment of heating rates. The temperature of initial degradation (T₀) is 0.448B + 362.4°C, the temperature at maximum degradation rate, that is, the peak temperature on a differential thermogravimetric curve (T_p) is 0.545B + 380.7°C, and the temperature of final degradation (T_f) is 0.476B + 409.4°C. The degradation rate at T_p is not affected by B, and its average value is 48.9%; the degradation rate at T_f is not affected by B either, and its average value is 99.3%. The reaction order (n) is 2.1 and is not affected by B. The reaction activation energy (E) and the frequency factor (A) increase along with B, and the apparent reaction activation energy (E₀) is 254.6 kJ/mol. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2952–2955, 2002     

Synthesis and properties of 2-vinylnaphthalene–EPDM–methyl methacrylate graft copolymer

A graft copolymer of 2-vinylnaphthalene (2-VN) and methyl methacrylate (MMA) onto ethylene–propylene–diene terpolymer (EPDM) was synthesized in tetrahydrofuran using benzoyl peroxide. The effects of EPDM content, and ratio of 2-VN to MMA, reaction time, reaction temperature, and initiator concentration in the graft copolymerization were examined. The light resistance, thermal stability, and the tensile properties of the graft copolymer were investigated by using Fade-o-Meter, thermogravimetric analyzer, and tensile tester. It was found that the light resitance and the heat resistance as well as the tensile strength of the graft copolymer are considerably better than those of the acrylonitrile–butadiene–styrene (ABS) copolymer. © 1994 John Wiley & Sons, Inc.     

Engineering properties of electron beam‐crosslinked ethylene methyl acrylate copolymer

Effect of electron beam on mechanical, thermal, and morphological properties of ethylene methyl acrylate copolymer, grade Elvaloy 1335 has been investigated. The copolymer was subjected to varying doses of electron beam radiation with different proportion of the sensitizer trimethylolpropane trimethacrylate (TMPTMA). It was observed that with increase in electron beam dose, the physicomechanical properties of the crosslinked copolymer improve, reaches an optimum level and subsequently deteriorates. The thermal properties as envisaged from thermogravimetric analysis and differential scanning calorimetric studies revealed stability of the crosslinked irradiated samples over that of the unirradiated ones. The thermal stability was also found to attain the maximum at the same level of radiation and sensitizer. The morphological studies showed consistency with the mechanical properties. Based on the overall study, it may be concluded that ethylene methyl acrylate copolymer with 1 phr TMPTMA at 60 kGy radiation dose is the optimum condition within the range studied in this investigation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of emulsion copolymer of N‐cyclohexylmaleimide and methyl methacrylate

Copolymers of N‐cyclohexylmaleimide (ChMI) and methyl methacrylate (MMA) were synthesized by the emulsion semibatch copolymerization method. The effects of the monomer mixture composition on the average molecular weight (M_n and M_w ), glass transition temperature (T_g), degradation temperature, mechanical properties, and rheological behavior of the copolymers were investigated. The results show that M_n and M_w have maximum values when the ChMI feed content was about 20% (by wt). The degradation temperature and T_g of the copolymers increase with increasing ChMI moieties in the copolymer. The mechanical properties (tensile strength and impact strength) decrease with an increasing ChMI feed content. All copolymers in the melt show pseudoplastic behavior. The flow index n increases with an increasing ChMI feed content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1070–1075, 2002; DOI 10.1002/app.10394     

Transparent poly(methyl methacrylate‐co‐butyl acrylate) nanofibers

Nanofibers of n‐Butyl Acrylate/Methyl Methacrylate copolymer [P(BA‐co‐MMA)] were produced by electrospinning in this study. P(BA‐co‐MMA) was synthesized by emulsion polymerization. The structural and thermal properties of copolymers and electrospun P(BA‐co‐MMA) nanofibers were analyzed using Fourier transform infrared spectroscopy–Attenuated total reflectance (FTIR–ATR), Nuclear magnetic spectroscopy (NMR), and Differential scanning calorimetry (DSC). FTIR–ATR spectra and NMR spectrum revealed that BA and MMA had effectively participated in polymerization. The morphology of the resulting nanofibers was investigated by scanning electron microscopy, indicating that the diameters of P(BA‐co‐MMA) nanofibers were strongly dependent on the polymer solution dielectric constant, and concentration of solution and flow rate. Homogeneous electrospun P(BA‐co‐MMA) fibers as small as 390 ± 30 nm were successfully produced. The dielectric properties of polymer solution strongly affected the diameter and morphology of electrospun polymer fibers. The bending instability of the electrospinning jet increased with higher dielectric constant. The charges inside the polymer jet tended to repel each other so as to stretch and reduce the diameter of the polymer fibers by the presence of high dielectric environment of the solvent. The extent to which the choice of solvent affects the nanofiber characteristics were well illustrated in the electrospinning of [P(BA‐co‐MMA)] from solvents and mixed solvents. Nanofiber mats showed relatively high hydrophobicity with intrinsic water contact angle up to 120°. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4264–4272, 2013     

Synthesis,characterization, and mechanical property of poly(urethane‐glycidyl methacrylate‐methyl methacrylate) hybrid polymers

Hybrid particles of polyurethane (PU) containing a number of small poly(methyl methacrylate) (PMMA) nanoparticles inside were prepared using glycidyl methacrylate (GMA) monomer as a linker between PU and PMMA; the resulting polymers were poly (urethane‐glycidyl methacrylate‐methyl methacrylate) (PUGM). It was found that the average particle size (D_p) of the PU particles decreased by the inclusion of PMMA particles possibly owing to the low‐solution viscosity of PU. However, D_p of the PUGM hybrid particles increased with increasing the number of covalent bonds between PMMA and PU, which might be due to decreasing the amount of ionic groups per PU chain. Subsequently, the tensile properties of the films made of the PUGM hybrid particles were investigated. It was observed that the modulus of the PU films increased upon the addition of PMMA particle because of a filler effect. In addition, it was seen that the modulus of PUGM hybrid films increased further with increasing the number of covalent bonds. This was attributed to “restricted mobility” of PU chains anchored to the PMMA particles. It was also observed that the tensile strength changed only slightly for PUGM particles, suggesting that the PU matrix was probably responsible for the necking behavior of the films. The elongation of the samples was found to depend on both the presence of covalent bonds between the PMMA particles and PU matrix and the reduced mobility of the PU chains anchored to PMMA particles. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and thermal properties of poly(methyl methacrylate)‐poly(L‐lactic acid)‐poly(methyl methacrylate) tri‐block copolymer

Poly(methyl methacrylate)‐poly(L ‐lactic acid)‐poly(methyl methacrylate) tri‐block copolymer was prepared using atom transfer radical polymerization (ATRP). The structure and properties of the copolymer were analyzed using infrared spectroscopy, gel permeation chromatography, nuclear magnetic resonance (¹H‐NMR, ¹³C‐NMR), thermogravimetry, and differential scanning calorimetry. The kinetic plot for the ATRP of methyl methacrylate using poly(L ‐lactic acid) (PLLA) as the initiator shows that the reaction time increases linearly with ln[M]₀/[M]. The results indicate that it is possible to achieve grafted chains with well‐defined molecular weights, and block copolymers with narrowed molecular weight distributions. The thermal stability of PLLA is improved by copolymerization. A new wash‐extraction method for removing copper from the ATRP has also exhibits satisfactory results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and properties of high oil‐absorbent 4‐tert‐butylstyrene‐EPDM‐divinylbenzene graft terpolymer

The graft crosslinking polymerization of 4‐tert‐butylstyrene (tBS) and divinylbenzene (DVB) onto ethylene–propylene–diene (EPDM) was carried out in toluene by using benzoyl peroxide (BPO) as an initiator. The synthesized graft terpolymer, tBS‐EPDM‐DVB (PBED), was extracted with tetrahydrofuran (THF) into gel (called as PBED I) and sol, and then they were identified by infrared (IR) spectroscopy. The effects of solvent amount, molar ratio of DVB to tBS, EPDM content, initiator concentration, reaction temperature, and reaction time on the graft crosslinking polymerization were examined. Among them, solvent amount and molar ratio of DVB to tBS were the important factors for this reaction system. Maximum oil absorbency of PBED I was 84.0 g/g but its oil‐absorption kinetic rate was very low. Sol PBED can be reused as oil absorbent (named as PBED II) through photocrosslinking by ultraviolet light irradiation. Although the oil absorbencies of PBED II were lower than those of PBED I in most cases, their oil absorption kinetic rates were higher than oil absorbencies of PBED I. The highest value of oil absorbency of PBED II was 56.0 g/g. The thermal stability of PBED I was studied by TGA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2119–2129, 2002     

High oil‐absorptive composites based on 4‐tert‐butylstyrene‐EPDM‐divinylbenzene graft polymer

4‐tert‐Butylstyrene‐EPDM‐divinylbenzene graft polymer (PBED) was prepared by graft crosslinking polymerization in toluene using BPO as an initiator. Gel and sol of PBED were isolated by extraction with tetrahydrofuran (THF). Sol PBED can be reused as oil absorbent through cross‐linking by ultraviolet irradiation. After swelling in oil, crosslinked polymers have poor gel strength to be taken out of oil wholly at high absorbency, although they possess strong mechanical strength in their dry states. As known, composite technique is one of the useful methods for material reinforcement. Fibres, sponges and non‐woven fabrics were used as reinforcers or supporters in this work. Oil absorbency was measured by method ASTM (F726‐81) and swelling kinetics of the composite was evaluated by an experimental equation. The gel strength parameter S, the relaxation exponent n, and the fractal dimension d_f of polymer and some composites in pseudo‐critical gel state were determined from oscillatory shear measurements by a dynamic rheometer. Mechanical properties and the morphologies of some composites were measured with a tensile tester and scanning electron microscopy, respectively. © 2001 Society of Chemical Industry