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.     

Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2

A copolymer of styrene and maleic anhydride was synthesized by free radical polymerization at 80°C using N,N‐dimethylformamide (DMF) as solvent and benzoylperoxide as initiator. The monomer feed ratio of styrene to maleic anhydride was varied in the range of 1 : 1 : to 3 : 1. The polymer yield was found to decrease with increase in styrene in the feed. The molecular weight of copolymers which were formed by taking styrene to maleic anhydride ratio of 1 : 1, 2 : 1, and 3 : 1, as determined by Ostwald Viscometery were about 1862, 2015, and 2276 respectively. The acid values of abovementioned three copolymers were found to be 480, 357, and 295, respectively. The typical viscosity values of 20% solids in ammonical solution of copolymers formed by taking feed ratios of Sty : MAn as 1 : 1 and 2 : 1 were 26 and 136 cp, respectively. For the feed ratio 3 : 1, a gel was formed. The synthesized copolymers were hydrolyzed by alkalis, namely, NaOH, KOH, and NH₄OH. The dispersing ability of hydrolyzed styrene‐maleic anhydride (SMA) copolymers for dispersion of titanium dioxide was studied. The modified SMA copolymers were found to be effective dispersants for TiO₂. Among the three alkalis studied, the Sodium salts of SMA were found to give better dispersion. The copolymer having a 1 : 1 feed ratio showed the best dispersing ability for TiO₂ particles among the three ratios studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3194–3205, 2007     

Morphology of nylon 6/acrylonitrile–butadiene–styrene blends compatibilized by a methyl methacrylate/maleic anhydride copolymer

The morphologies of nylon 6/acrylonitrile–butadiene–styrene blends compatibilized with a methyl methacrylate/maleic anhydride copolymer, with 3–20 wt % maleic anhydride, were examined by transmission electron microscopy. Some staining techniques were employed for identifying the various phases. The binary blends were immiscible and exhibited poor mechanical properties that stemmed from the unfavorable interactions among their molecular segments. This produced an unstable and coarse phase morphology and weak interfaces among the phases in the solid state. The presence of the copolymer in the blends clearly led to a more efficient dispersion of the acrylonitrile–butadiene–styrene phase and consequently optimized Izod impact properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3512–3518, 2003     

Blend compatibilizers based on silane‐ and maleic anhydride–modified polyolefins

Polypropylene (PP)/polyamide blends were compatibilized with PP modified with vinylsilane or maleic anhydride and ethylene–propylene random (EPR) copolymer modified with maleic anhydride. The thermal behavior, mechanical properties, and morphology of the blends were investigated. Thermal analysis showed that the polyamide crystallization temperatures shifted downward with all compatibilizers, whereas its melting behavior did not change. On the other hand, polypropylene crystallization temperatures shifted upward in all cases, except for blends containing EPR modified with maleic anhydride. Tensile strength and elongation at break increased for blends compatibilized with modified PP. Blends containing up to 7% of EPR modified with maleic anhydride did not show good yield stresses. The morphology of the blends showed a finer dispersion of the polyamide minor phase in the PP matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2492–2498, 2003     

Acrylonitrile‐based copolymer membranes for the separation of methanol from a methanol–toluene mixture through pervaporation

The membrane selection criteria for the preferential permeation of a particular component were examined for the pervaporative separation of methanol from a mixture of methanol and toluene. One polyacrylonitrile homopolymer and five different copolymer membranes (i.e., acrylonitrile with maleic anhydride, acrylic acid, methacrylic acid, methyl methacrylate, and styrene) were prepared through emulsion polymerization. All these monomers were selected on the basis of the solubility parameter concept. The second monomer had an influence on the permselectivity and flux, and this effect was investigated. The structures of the copolymers, the features of their sorption layers, and their permeation paths were examined. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 243–252, 2005     

Bulk modification of styrene–butadiene–styrene triblock copolymer with maleic anhydride

The bulk modification of SBS rubber with maleic anhydride in a mixing chamber of a Haake rheomixer was studied. The effect of temperature, maleic anhydride, and benzoyl peroxide concentrations on the grafting efficiency was evaluated. High grafting efficiency was achieved when the ratio of peroxide and maleic anhydride concentration was high. On the other hand, on this condition high insoluble fraction was generated. The addition of a diamine, 4,4′‐diaminediphenylmethane to the reaction mixture minimizes the amount of insoluble polymer. However, the grafted MAH content also decreases. The graft copolymer was characterized by infrared spectroscopy and the grafting extension was determined by titration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2953–2960, 2002; DOI 10.1002/app.10355     

Blends of acrylonitrile–butadiene–styrene/waste poly(ethylene terephthalate) compatibilized by styrene maleic anhydride

Waste poly(ethylene terephthalate) (PET) from thin bottles was blended with acrylonitrile–butadiene–styrene (ABS) copolymer in different proportions, up to 10 wt %. Styrene maleic anhydride (SMA) copolymer was used as a compatibilizer. The tensile strength and heat deflection temperature of the blend were higher than that of virgin ABS. Flexural modulus remained unaffected, although a slight decrease in impact property was observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2593–2599, 2001     

Hole structure and its formation in thin films of hydrolyzed poly(styrene maleic anhydride) alternating copolymers

Maleic anhydride moieties on the backbone chains of poly(styrene maleic anhydride) alternating copolymer (SMA) hydrolyzed in a THF solution containing water and hydrochloric acid. Well‐arrayed holes were obtained in spin‐cast thin hydrolyzed SMA films on a single crystal silicon wafer, and the hole diameter and its distribution were measured with AFM data. Results showed that the hole size was almost uniform, and was influenced by water content when spin speed was kept unchanged. The THF solution with a SMA concentration of about 1 g/mL and weight ratio H₂O/SMA of 1/3 produced holes having an average diameter of 0.60 μm and depth of 206.12 nm, when cast at a spin speed of 1400 rpm. It was noted that the formation of the holes in thin hydrolyzed SMA film was different from the dewetting process in thin homopolymer films, but was associated with the intrinsic properties of the copolymer forming the films. The surfactant effect of hydrolyzed SMA was suggested to interpret the formation of the holes. The holes were described to be the traces of water droplets that were emulsified by the hydrolyzed SMA during casting. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 267–274, 2000     

Synthesis of water‐reducible acrylic–alkyd resins based on modified palm oil

Water‐reducible acrylic–alkyd resins were synthesized from the reaction between monoglycerides prepared from modified palm oil and carboxy‐functional acrylic copolymer followed by neutralization of carboxyl groups with diethanolamine. Modified palm oil was produced by interesterification of palm oil with tung oil at a weight ratio of 1 : 1, using sodium hydroxide as a catalyst, whereas carboxy‐functional acrylic copolymer was prepared by radical copolymerization of n‐butyl methacrylate and maleic anhydride. The amount of acrylic copolymer used was from 15 to 40% by weight, and it was found that homogeneous resins was obtained when the copolymer content was 20–35 wt %. All of the prepared water‐reducible acrylic–alkyd resins were yellowish viscous liquids. Their films were dried by baking at 190°C and their properties were determined. These films showed excellent water and acid resistance and good alkali resistance. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1170–1175, 2005     

Blends of bisphenol A polycarbonate and rubber‐toughened styrene–maleic anhydride copolymers

The morphology and mechanical properties of polycarbonate (PC) blends with rubber‐toughened styrene–maleic anhydride copolymer materials (TSMA) were investigated and compared with the properties of blends of PC with acrylonitrile–butadiene–styrene (ABS) materials. The PC/TSMA blends showed similar composition dependence of properties as the comparable PC/ABS blends. Polycarbonate blends with TSMA exhibited higher notched Izod impact toughness than pure PC under sharp‐notched conditions but the improvements are somewhat less than observed for similar blends with ABS. Since PC is known for its impact toughness except under sharp‐notched conditions, this represents a significant advantage of the rubber‐modified blends. PC blends with styrene–maleic anhydride copolymer (SMA) were compared to those with a styrene–acrylonitrile copolymer (SAN). The trends in blend morphology and mechanical properties were found to be qualitatively similar for the two types of copolymers. PC/SMA blends are nearly transparent or slightly pearlescent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1508–1515, 1999     

Synthesis of a maleic anhydride grafted polypropylene–butadiene copolymer and its application in polypropylene/styrene–butadiene–styrene triblock copolymer/organophilic montmorillonite composites as a compatibilizer

A maleic anhydride grafted propylene–butadiene copolymer (MPPB) was prepared. Fourier transform infrared spectroscopy and ¹H‐NMR results indicate that the maleic anhydride molecules reacted with the double bond in the butadiene unit of the propylene–butadiene copolymer (PPB), and the grafting percentage increased with the butadiene content in the initial copolymer. The gel permeation chromatography results show that the introduction of butadiene in the copolymer prevented the degradation of PPB. The MPPB was applied in polypropylene (PP)/styrene‐butadiene‐styrene triblock copolymer (SBS)/organophilic montmorillonite (OMMT) composites as a compatibilizer. In the presence of 10‐phr MPPB, the impact strength of the composite was improved by about 20%. X‐ray diffraction patterns indicated the formation of the β‐phase crystallization of PP in the presence of MPPB, and a significant decrease in the spherulite size was observed. Transmission electron microscopy (TEM) images showed that the OMMT was better dispersed in the matrix upon the inclusion of MPPB. A better distribution of the rubber phase and a rugged fracture surface were observed in the scanning electron microscopy images as the MPPB proportion was increased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Surface pattern in thin poly(styrene–maleic anhydride) films

Monodispersed poly(styrene–maleic anhydride) alternating copolymer (SMA) is synthesized through radical polymerization, and characterized by GPC, DSC, FT-IR and ¹H NMR spectra. The mole fraction, χ, of styrene in the copolymer is 0.51, determined from integrated ¹H NMR spectrum, this value is consistent with the alternating structure. FT-IR spectra show that maleic anhydride moieties on the backbone chains hydrolyze in a THF solution containing water, and HCl can accelerate the hydrolysis process. Atomic force microscopy reveals that well-arrayed and uniform-sized holes formed in thin SMA films on single crystal silicon wafer substrates spin-cast from the THF solutions containing HCl. HCl can also influence hydrogen bonding between the carboxylic acid groups in the THF solution, which is crucial for the formation of holes in the thin films. The volatilization process in the spin-casting is divided into two stages, THF and water volatilization. The formation of holes is interpreted as the trace of water droplets emulsified by the hydrolyzed SMA in the second stage, i.e. water volatilization. Results also indicate that there are both mobile and bound water populations in the solution, and that the bound water is responsible for the hole or valley pattern of these thin films.     

Amic acids of alphamethyl styrene and maleic‐anhydride copolymer as a dispersing agent

Alphamethyl styrene (AMS) and maleic anhydride (MAn) were copolymerized in 2‐butanone using benzoyl peroxide as initiator. Low molecular weight (8000) of alphamethyl styrene‐maleic anhydride copolymer was prepared using AMS dimer as a chain‐transfer agent. This copolymer was then treated with two different amines, such as dibutylamine and diethanolamine, having different hydrophilicity, to obtain the corresponding amic acids. Application of these amic acids as a dispersing agent to disperse titanium dioxide (TiO₂) in water was studied. The Daniel Flow point method was used to assess the dispersing ability of these amic acids, and diethanolamic acid was found to show the better dispersing property. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 424–428, 2000     

Polyaniline encapsulated microporous polymer beads and their vapor and gas adsorption behavior

Styrene‐maleic acid copolymer beads and styrene‐divinylbenzene beads were encapsulated with polyaniline by insitu oxidative polymerization of aniline. These beads both in unmodified and encapsulated forms were studied for their organic vapor and hydrogen adsorption behavior at 30°C and reduced pressure. Enhanced adsorption of hydrogen to the extent of 4.9 mass % was observed for encapsulated styrene‐maleic acid copolymer beads. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 297–303, 2007     

Vulcanization of 1-chlorobutadiene–butadiene rubber with diepoxy compound

Diepoxy vulcanization system of 1-chlorobutadiene–butadiene rubber(CB–BR) having hydroxyl groups with diglycidyl ether of bisphenol A (DGEBA) was studied in the presence of acid anhydrides. Phthalic anhydride (PAn), hexahydrophthalic anhydride (HAn), maleic anhydride (MAn), and succinic anhydride (SAn) were investigated as occuring agents. The results of this investigation indicated that the hydroxyl groups attached to the polybutadiene backbone react with DGEBA to afford a CB–BR vulcanizate rate depended on the kinds of acid anhydrides in the following order: PAn > MAn > SAn > HAn. It is assumed that the reaction between the hydroxyl group in CB–BR and acid anhydride was the rate-determining step. The vulcanization of CB–BR with a higher amount of DGEBA afforded resinous rubber vulcanizates. Thus, DGEBA was concluded to act not only as a curing agent, but also as a reinforcing agent for CB–BR. © 1995 John Wiley & Sons, Inc.     

Effect of anhydride‐modified ethylene–propylene–diene rubber and ethylene–vinyl acetate copolymers on the compatibilization of nitrile rubber/ethylene–propylene–diene rubber blends

The effects of maleic anhydride modified ethylene–propylene–diene rubber (EPDMMA) and maleic anhydride modified ethylene–vinyl acetate (EVAMA) on the compatibilization of nitrile rubber (NBR)/ethylene–propylene–diene rubber (70:30 w/w) blends vulcanized with a sulfur system were investigated. The presence of EPDMMA and EVAMA resulted in improvements of the tensile properties, whereas no substantial change was detected in the degree of crosslinking. The blend systems were also analyzed with scanning electron microscopy and dynamic mechanical thermal analysis. The presence of EVAMA resulted in a blend with a more homogeneous morphology. The compatibilizing effect of this functional copolymer was also detected with dynamic mechanical analysis. A shift of the glass‐transition temperature of the NBR phase toward lower values was observed. The presence of EPDMMA and EVAMA also increased the thermal stability, as indicated by an improvement in the retention of the mechanical properties after aging in an air‐circulating oven. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2408–2414, 2003     

Preparation of fine powdery copolymer with crosslinkage and monoalkyl maleate unit

In order to prepare fine powdery and crosslinked copolymer as a foaming agent and a modifier for polypropylene, the following processes were investigated: (1) polymerization of monoalkyl maleate–styrene–divinylbenzene; (2) polymerization of monoalkyl maleate–maleic anhydride–styrene–divinylbenzene; (3) polymerization of maleic anhydride–styrene–divinylbenzene and esterification of the copolymer with methanol, and (4) polymerization of maleic anhydride–styrene–divinylbenzene in the presence of methanol. The thermal treatment of copolymer thus obtained and the foaming ability for polypropylene were then investigated.     

Thermal stability of copolymer acrylamide–maleic anhydride

The thermal degradation of copolymer acrylamide–maleic anhydride prepared in various solvents (benzene, dioxane, methylethyl ketone) and different monomer ratios was investigated. The techniques of thermogravimetry (TG and DTG) and differential scanning calorimetry (DSC) were used. The IR spectra of degraded copolymers are discussed.     

Synthesis and properties of a new type of unsaturated poly(ester amide)

A new type of unsaturated poly(ester amide), maleic anhydride–phthalic anhydride–ethylene glycol–neopentylene glycol–anthranilic acid copolymer, was prepared by melt polycondensation. The copolymer was characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The viscosity of the polymer was measured with a Ubbelohde viscometer. The compressive strength of the crosslinked unsaturated poly(ester amide) under different heat‐treatment conditions was measured. Studies of its degradation behavior were carried out in simulated body fluid at pH 7.4 (37°C), and the compressive strength loss of the crosslinked unsaturated poly(ester amide) was also measured after different degradation times. The copolymer was hydrolyzed in a 1.0‐mol/L NaOH standard solution at room temperature. All of the preliminary results suggest that the new unsaturated poly(ester amide) might potentially be used as a new type of bone‐fixation material. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and properties of styrene–ethylene–butylene–styrene block copolymer/clay nanocomposites: I. Effect of clay content and compatibilizer types

BACKGROUND: Polymer/clay (silicate) systems exhibit great promise for industrial applications due to their ability to display synergistically advanced properties with relatively small amounts of clay loads. The effects of various compatibilizers on styrene–ethylene–butylene–styrene block copolymer (SEBS)/clay nanocomposites with various amounts of clay using a melt mixing process are investigated. RESULTS: SEBS/clay nanocomposites were prepared via melt mixing. Two types of maleated compatibilizers, styrene–ethylene–butylene–styrene block copolymer grafted maleic anhydride (SEBS‐g‐MA) and polypropylene grafted maleic anhydride (PP‐g‐MA), were incorporated to improve the dispersion of various amounts of commercial organoclay (denoted as 20A). Experimental samples were analyzed using X‐ray diffraction and transmission electron microscopy. Thermal stability was enhanced through the addition of clay with or without compatibilizers. The dynamic mechanical properties and rheological properties indicated enhanced interaction for the compatibilized nanocomposites. In particular, the PP‐g‐MA compatibilized system conferred higher tensile strength or Young's modulus than the SEBS‐g‐MA compatibilized system, although SEBS‐g‐MA seemed to further expand the interlayer spacing of the clay compared with PP‐g‐MA. CONCLUSION: These unusual results suggest that the matrix properties and compatibilizer types are crucial factors in attaining the best mechanical property performance at a specific clay content. Copyright © 2007 Society of Chemical Industry