Maleic Anhydride Groups Research Articles

Melt grafting of maleic anhydride onto low-density polyethylene/polypropylene blends

Grafting of maleic anhydride (MAH) onto low-density polyethylene/polypropylene (LDPE/PP) blends was performed by melt extruding in the presence of dicumyl peroxide (DCP). The melt viscosities of the grafted blends were measured by a capillary rheometer and the grafting degrees were determined by a back-titration procedure. Compared to the MAH grafted LDPE, the MAH grafted LDPE/PP (90/10) blend had lower viscosity when the DCP or MAH concentration increased in the grafting procedure. However, the grafting degree of the MAH grafted LDPE/PP (90/10) blend was almost the same as or a little higher than that of the MAH grafted LDPE. The characteristic groups of MAH in the grafted products were measured by Fourier transform infrared spectroscopy (FT-IR). The results showed that MAH had grafted onto both LDPE and PP in the blend.

Toughening of polypropylene with styrene/ethylene‐butylene/styrene tri‐block copolymer: Effects of reactive and nonreactive compatibilization

AbstractThe effects of compatibilization on the toughening of polypropylene (PP) by melt blending with styrene/ethylene‐butylene/styrene tri‐block copolymer (SEBS) in a twin‐screw extruder were investigated. The compatibilizers used were SEBS functionalized with maleic anhydride (SEBS‐g‐MA), PP functionalized with acrylic acid (PP‐g‐AA), and bifunctional compound p‐phenylenediamine (PPD). The effects of the compatibilization were evaluated through the mechanical properties as well as through the determination of the phase morphology of the blends by scanning electron microscopy. Reactive compatibilized blends show up to a 30‐fold increase in impact strength compared with neat PP; likely the result of the reaction of the bifunctional compound (PPD) with the acid acrylic and maleic anhydride groups, this increase in strength rendered both morphological and mechanical stability to these blends. The addition of PPD to the blends significantly changed their phase morphologies, leading to larger average diameters of the dispersed particles, probably as a result of the morphological stabilization at the initial processing steps during extrusion, with the occurrence of chemical reactions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3466–3479, 2002

Polymer microcapsules by interfacial polyaddition between styrene–maleic anhydride copolymers and amines

In the present study, styrene–maleic anhydride (SMA) copolymers were used as wall-forming materials in microencapsulation. The capsule membranes were formed by polyaddition at the interface between SMA copolymers dissolved in a dispersed relatively hydrophilic oil phase such as ethyl acetate, and a polyamine dissolved in the continuous aqueous phase. Microcapsules containing more hydrophobic core oils were prepared by either increasing the ratio of styrene to maleic anhydride groups in the copolymer, or by incorporating t-butyl styrene instead of styrene into the copolymer. Model compounds for insect sex pheromones, such as dodecyl acetate and dodecanol, were encapsulated in such SMA microcapsules, and release from these microcapsules into air was monitored over several weeks at room temperature. The relatively fast rate of release of core materials was attributed to the porous structure of the capsule walls, as confirmed by transmission and environmental scanning electron microscopy.

Preparation and performance characteristics of short‐glass‐fiber/maleated styrene–ethylene–butylene–styrene/polypropylene hybrid composites

AbstractEighty/twenty polypropylene (PP)/styrene–ethylene–butylene–styrene (SEBS) and 80/20 PP/maleated styrene–ethylene–butylene–styrene (SEBS‐g‐MA) blends reinforced with 30 wt % short glass fibers (SGFs) were prepared by extrusion and subsequent injection molding. The influence of the maleic anhydride (MA) functional group grafted to SEBS on the properties of SGF/SEBS/PP hybrid composites was studied. Tensile and impact tests showed that the SEBS‐g‐MA copolymer improved the yield strength and impact toughness of the hybrid composites. Extensive plastic deformation occurred at the matrix interface layer next to the fibers of the SGF/SEBS‐g‐MA/PP composites during impact testing. This was attributed to the MA functional group, which enhanced the adhesion between SEBS and SGF. Differential scanning calorimetry measurements indicated that SEBS promoted the crystallization of PP spherulites by acting as active nucleation sites. However, the MA functional group grafted to SEBS retarded the crystallization of PP. Finally, polarized optical microscopy observations confirmed the absence of transcrystallinity at the glass‐fiber surfaces of both SGF/SEBS/PP and SGF/SEBS‐g‐MA/PP hybrid composites. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1303–1311, 2002

Mechanical behavior and fracture toughness evaluation of maleic anhydride compatibilized short glass fiber/SEBS/polypropylene hybrid composites

Short glass fiber (SGF) reinforced polypropylene composites toughened with styrene-ethylene-butylene-styrene (SEBS) triblock copolymer were injection molded. The effect of maleic anhydride (MA) functional group on the mechanical performance of the hybrid composites was investigated. In this study, MA was either grafted to PP (PP-g-MA) or SEBS copolymer (SEBS-g-MA). The mPP blend was prepared by compounding 95% PP with 5% PP-g-MA. The matrix of hybrid composites consists of either SEBS/mPP or SEBS-g-MA/mPP. Tensile tests showed that SGF exhibits a beneficial effect for restoring the stiffness of the SEBS/mPP blend. Impact measurements on SEBS/mPP exhibited superior impact strength. However, the incorporation of SGF into SEBS/mPP and SEBS-g-MA/mPP blends reduced the impact strength considerably. SEM observations revealed that the SGF surfaces of both SGF/SEBS/mPP and SGF/SEBS-g-MA/mPP hybrids are coated with a thin layer of matrix material. This implied that the MA functional group of mPP improves the adhesion between SGF and PP, and between SGF and SEBS. The essential work of fracture (EWF) method revealed that a strong interfacial bonding between SGF and PP is detrimental to the fracture toughness of ternary SGF/SEBS/mPP and SGF/SEBS-g-MA/mPP hybrid composites. Finally, dynamic mechanical analysis showed that SGF increases the storage modulus but decreases the intensity of damping factor for the hybrids.

Nonisothermal crystallization and melting behavior of poly(3-hydroxybutyrate) and maleated poly(3-hydroxybutyrate)

Nonisothermal crystallization and melting behavior of poly(3-hydroxybutyrate) (PHB) and maleated PHB were investigated by differential scanning calorimetry using various cooling rates. The results show that the crystallization behavior of maleated PHB from the melt greatly depends on cooling rates and its degree of grafting. With the increase in cooling rate, the crystallization process for PHB and maleated PHB begins at lower temperature. For maleated PHB, the introduction of maleic anhydride group hinders its crystallization, causing crystallization and nucleation rates to decrease, and crystallite size distribution becomes wider. The Avrami analysis, modified by Jeziorny, was used to describe the nonisothermal crystallization of PHB and maleated PHB. Double melting peaks for maleated PHB were observed, which was caused by recrystallization during the heating process.

Biological reprocessing of mixed office waste (mow) using modified cellulase by production of functional copolymer

Copolymer containing functional groups such as polyethylene oxide (PEO) and maleic anhydride (MA) was synthesized to modify the cellulase. MA was attached to PEO allyl ester, which was the product of the reaction between PEO allyl alcohol and lauric acid. The number of ethylene oxide (EO) units in one PEO chain was varied from 10 to 40. MA groups of the copolymer formed the chemical bond with the amino acid groups of the cellulase in the modification reaction. When cellulase was modified with synthesized copolymer, modified enzyme showed high relative activity regardless of high degree of modification compared with other modification methods. In mixed office waste reprocessing, modified cellulase improved many physical properties of the paper including freeness, optical properties, and strengths compared to the conventional process. Even though native cellulase improved the physical properties, modified cellulase showed an increased tensile strength and internal bond over those of unmodified cellulase. From these results, modified cellulase method is an effective biological treatment that would save pulp resources in the reprocessing.

プラズマ照射した医薬品助剤を利用する新規なドラッグデリバリーシステムの開発 第１０報 スチレン‐（無水）マレイン酸共重合体を外層高分子とした二重錠剤へのプラズマ照射によるテオフィリンの放出制御

As a part of the development of the DDS device using plasma-irradiated polymer, the utility of poly(styrene-maleic anhydride) (SMAn) and poly(styrene-maleic acid) (SMA) was investigated. From the results of plasma degradation tests and the electron spin resonance (ESR) studies on plasma-irradiated SMAn and SMA, it was found that they were of intramolecular bifunctionality, cross-linkable phenyl group and degradable maleic anhydride or maleic acid group as an effect of plasma irradiation. Using these plasma characteristics, controlled-release tablets were designed by argon plasma irradiation on the outer layer of double-compressed tablet prepared from theophylline as a core material and SMAn or SMA as a single wall material. The dissolution profiles of theophylline from plasma-irradiated double-compressed tablet were sufficiently modified in comparison with one of non-plasma-irradiated tablet, depending on the set of chosen plasma operational conditions.

In situ compatibilization of polystyrene and polyurethane blends by using poly(styrene‐co‐maleic anhydride) as reactive compatibilizer

Blends of polystyrene (PS) and polyurethane (PU) elastomer were obtained by melt mixing, using poly(styrene-co-maleic anhydride) (SMA) containing 7 wt % of maleic anhydride groups as a reactive compatibilizer. Polyurethanes containing polyester flexible segments, PU-es, and polyether flexible segments, PU-et, were used. These polyurethanes were crosslinked with dicumyl peroxide or sulfur to improve their mechanical properties. The anhydride groups of SMA can react with the PU groups and form an in situ graft copolymer at the interface of the blends during their preparation. The rheological behavior was accompanied by torque versus time curves and an increase in the torque during the melt mixing was observed for all the reactive blends, indicating the occurrence of a reaction. Solubility tests, gel permeation chromatography, and scanning electronic microscopy confirmed the formation of a graft copolymer generated in situ during the melt blending. These results also indicate that this graft copolymer contains CC bond between SMA and PU chains. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2514–2524, 2001

Mechanochemical preparation and properties of a cellulose–polyethylene composite

Ball milling of crystalline cellulose with maleated polyethylene (MPE) yields a novel composite with ester bonds formed by reaction of the hydroxy groups of the cellulose with the maleic anhydride groups of MPE; the composite exhibits much improved toughness and ductility compared with the product formed by melt-mixing, probably because of the formation of an interphase of MPE chains bonded on cellulose particles.

Interfacial deposition of functionalized copolymers onto nanoemulsions produced by the solvent displacement method

Cationic nanoemulsions containing an oily core as potential carriers of nucleic acids were prepared by a solvent displacement method in the presence of a nonionic surfactant (Pluronic F68). With a view to functionalize such nanoemulsions for further incorporation of a fusogenic peptide, a poly(maleic anhydride-alt-methyl vinyl ether) (Mn=67,000) grafted with variable amount of acetylspermine (or acetylspermidine) and decylamine was nanodeposited during the nanoemulsion formation step. Functionalized nanoemulsions were characterized in terms of particle size (by quasi-elastic light scattering and electron microscopy), electrophoretic mobility and long-term stability as a function of the amount of polymer used in the formulation. It was found that increases in the level of the copolymer led to a reduction in the particle size and a decrease in colloidal stability. In addition, the incorporation of the grafted copolymers at the interface of the nanoemulsions was clearly evidenced, a shift towards low pH at the point of zero charge being attributed to the formation of carboxylic groups induced by hydrolysis of the residual maleic anhydride groups of the copolymer.

Improvement of the physical properties of reprocessed paper by using biological treatment with modified cellulase

A primary need for waste paper reprocessing is to preserve optical properties and the physical strength of the paper fibers. In this study, modified cellulase with copolymer, polyethylene oxide (PEO) derivatives and maleic anhydride (MA) was applied to the reprocessing of mixed office waste (MOW). Modified cellulase was prepared by a chemical reaction between amino groups of the cellulase and the MA functional groups of the copolymer. In MOW reprocessing, modified cellulase improved several physical properties of the paper including freeness, optical properties, and physical strength compared to the conventional process. Even though native cellulase improved the physical properties, paper treated with modified cellulase exhibited an increase in physical properties such as tensile strength and internal bond over those of unmodified cellulase. From these results, modified cellulase method is a new biological treatment that will save pulp resources, which are added to waste paper reprocessing to maintain the strength of paper.

In situ compatibilization of polystyrene and polyurethane blends by using poly(styrene-co-maleic anhydride) as reactive compatibilizer

Blends of polystyrene (PS) and polyurethane (PU) elastomer were obtained by melt mixing, using poly(styrene-co-maleic anhydride) (SMA) containing 7 wt % of maleic anhydride groups as a reactive compatibilizer. Polyurethanes containing polyester flexible segments, PU-es, and polyether flexible segments, PU-et, were used. These polyurethanes were crosslinked with dicumyl peroxide or sulfur to improve their mechanical properties. The anhydride groups of SMA can react with the PU groups and form an in situ graft copolymer at the interface of the blends during their preparation. The rheological behavior was accompanied by torque versus time curves and an increase in the torque during the melt mixing was observed for all the reactive blends, indicating the occurrence of a reaction. Solubility tests, gel permeation chromatography, and scanning electronic microscopy confirmed the formation of a graft copolymer generated in situ during the melt blending. These results also indicate that this graft copolymer contains CC bond between SMA and PU chains. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2514–2524, 2001

Reaction effect on the properties of poly(ethylene terephthalate) and poly(styrene-co-maleic anhydride) blends

Poly(ethylene terephthalate) (PET) was blended with polystyrene (PS) and poly(styrene-co-maleic anhydride) (PScMA). The two blend systems were immiscible based on the glass transition temperatures measured by differential scanning calorimetry (DSC). In the case of 70 and 90% PScMA blends, the reaction between ester groups of PET and maleic anhydride (MAH) sites on PScMA occurred during melt mixing at 280°C for 30min. The reaction was confirmed indirectly by thermal data, from the increase in the complex viscosity and from the solubility difference between the blends. The particle size in PET/PScMA reactive blends was smaller than that of the non-reactive blends. The mechanical properties such as tensile strength and modulus were not affected by the reaction.

On the production of compatibilized polyethylene terephthalate-styrene butadiene rubber blends

Styrene-butadiene rubber (SBR) is chemically modified with maleic anhydride (MAH) in a continuous process (reactive extrusion) at three different extrusion speeds with and without reaction initiator (benzoyl peroxide). The resulting modified rubber is used to produce compatibilized blends with polyethylene terephthalate (PET). The amount of grafted MAH groups on the rubber is determined by chemical titration and the degree of grafting is measured by infrared analysis. The degree of compatibilization between SBR and PET is determined indirectly through measurements of mechanical properties and average molecular weight of the blends. The anhydride and peroxide concentration influences the grafting reaction strongly and hence the mechanical properties and impact resistance of the blends. Compatibilization of the elastomeric and plastic phases at specific processing conditions gives rise to large improvements in the impact resistance of the blend over that of PET alone. © 2000 John Wiley & Sons, Inc. Adv Polym Techn 19: 34–40, 2000

Synthesis and properties of reactively compatibilized polyester and polyamide blends

The functionalization of poly(butylene terephthalate) (PBT) has been accomplished in a twin screw extruder by grafting maleic anhydride (MA) using a free radical polymerization technique. The resulting PBT-g-MA was successfully used as a compatibilizer for the binary blends of polyester (PBT) and polyamide (PA66). Enhanced mechanical properties were achieved for the blend containing a small amount (as low as 2.5 %) of PBT-g-MA compared to the binary blend of unmodified PBT with PA66. Loss and storage moduli for blends containing compatibilizer were higher than those of uncompatibilized blends or their respective polymers. The grafting and compatibilization reactions were confirmed using FTIR and 13C NMR spectroscopy. The properties of these blends were studied in detail by varying the amount of compatibilizer, and the improved mechanical behaviour was correlated with the morphology with the help of scanning electron microscopy. Morphology studies also revealed the interfacial interaction in the blend containing grafted PBT. The improvement in the properties of these blends can be attributed to the effective interaction of grafted maleic anhydride groups with the amino group in PA66. The results indicate that PBT-g-MA acts as an effective compatibilizer for the immiscible blends of PBT and PA66. © 2000 Society of Chemical Industry

Preparation and mechanical properties of polypropylene-clay hybrids based on modified polypropylene and organophilic clay

Polypropylene–clay hybrids (PPCHs) were prepared by melt blending maleic anhydride modified PP and organophilic clay. In these PPCHs the silicate layers of the clay were exfoliated and dispersed to the monolayers. The hybridization of the clay in PP was achieved with modified PP with a small amount of maleic anhydride groups. The tensile modulus of the PPCH with 5 wt % clay was 1.9 times higher than that of the matrix resin at 25°C. The dynamic storage moduli (E′) of the PPCHs were also higher than those of the modified PP. The E′ was 2.5 times higher than that of the matrix resin at 60°C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1918–1922, 2000

Synthesis and characterization of a novel blend of polypropylene with Chlorella

A novel blend of polypropylene (PP) with Chlorella, a natural microalga, was synthesized successfully by a melt-mixing method with maleic anhydride-modified polypropylene (MPP) as a compatibilizer. The adhesion of hydrophobic PP to hydrophilic Chlorella is based on the formation of chemical bonds between the maleic anhydride groups of MPP and hydroxy groups of Chlorella through solid-phase esterification. The single maleic anhydride groups have the highest reactivity with Chlorella. From the comparison with PP–Chlorella blends without MPP, the ester bonds between MPP and Chlorella cause a decrease in crystallinity of the MPP matrix which is a primary origin of the decrease in melting and solidification enthalpies of the MPP–Chlorella blend, and induce intensive expansion of the MPP matrix around the Chlorella particles which decreases the glass transition temperature. Consequently, the PP–Chlorella blend with MPP exhibits a marked increase in tensile strength and Young's modulus compared with the blend without MPP because of the stronger interactions between MPP and Chlorella than those between Chlorella cells.

Theoretical Density Functional Analysis of Maleic Anhydride Chemisorption on Pd(111), Re(0001), and Bimetallic PdML/Re(0001) and PdML/Mo(110) Pseudomorphic Overlayers

Nonlocal density functional theory (DFT) calculations were performed to analyze the di-σ, π, and atop chemisorption modes of maleic anhydride on the close-packed Pd(111), Re(0001), and pseudomorphic monolayers of Pd on Re(0001) [PdML/Re(0001)] and Pd on Mo(110) [PdML/Mo(110)] surfaces. The DFT-computed binding energies for maleic anhydride in the atop, π, and di-σ modes on Pd(111) are −28, −34, and −83 kJ/mol, respectively. The calculated adsorption energy and vibrational frequencies for di-σ adsorption are in good agreement with the UHV-TPD and HREELS data of Xu and Goodman (Langmuir 1996, 12, 1807−1816). The atop, π, and di-σ adsorptions of maleic anhydride on Re(0001) are significantly stronger than on Pd(111), with binding energies of −38, −210, and −200 kJ/mol, respectively. The π adsorption mode of maleic anhydride on Re(0001), in particular, is much stronger than that on Pd(111), due to additional interactions of the carbonyl groups of maleic anhydride with the Re(0001) surface. Adsorption energies for maleic anhydride on the bimetallic Pd/Re(0001) and Pd/Mo(110) surfaces are 10−20 kJ/mol weaker than on monometallic Pd(111). This decrease in the adsorption energy is explained on the basis of formal chemisorption theory. Using the analysis of Hammer and Nørskov (Nature 1995, 376, 238, and In Chemisorption and Reactivity on Supported Clusters and Thin Films; Lambert, R. M., Pacchioni, G., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1997; pp 285−351), the di-σ adsorption energies have been correlated to the location of the d band center for the clean metal surface. Calculations indicate that the strong Pd−Re and Pd−Mo interactions in the bimetallic surfaces shift the d band center for the surface Pd layer away from the Fermi level. This weakens the interaction of the olefinic group of maleic anhydride with the bimetallic PdML/Re(0001) and PdML/Mo(110) surfaces. The only exception is that for π-bound maleic anhydride on the PdML/Mo(110) surface, where the larger Pd−Pd spacing, relative to Pd(111), allows for better overlap of the carbonyl group π-orbitals with the metal d-orbitals. The π-mode binding energy on the PdML/Mo(110) surface is, therefore, stronger than the corresponding binding energy on Pd(111). The results are consistent with the experimental observations of Xu and Goodman (Langmuir 1996, 12, 1807−1816).

Reactive compatibilisation of heterogeneous ethylene propylene rubber (EPM)/nylon 6 blends by the addition of compatibiliser precursor EPM-g-MA

Blends of ethylene–propylene rubber (EPM) and nylon 6 are immiscible and highly incompatible. These blends are characterised by a two-phase morphology, narrow interface, and poor physical and chemical interactions across the phase boundaries. Therefore a reactive route was employed to compatibilise these blends by the addition of maleic anhydride grafted EPM (EPM-g-MA). In this reactive route, the maleic anhydride group of EPM reacts with the amino end group of nylon forming a graft copolymer of nylon and EPM (nylon-g-EPM) at the blend interface which decreases the interfacial tension and reduces the coalescence. The influence of the concentration of EPM-g-MA, blend composition, molecular weight of nylon 6, mode of addition of EPM-g-MA and mixing time on the phase morphology of the blends was studied quantitatively by scanning electron microscopy and image analysis. It was found that the addition of EPM-g-MA reduces the domain size of the dispersed phase followed by a levelling off at high concentrations; the levelling off is an indication of interfacial saturation. The optimum amount of the compatibiliser required to saturate unit volume of the interfacial zone was estimated from the emulsification curves. This optimum concentration of the compatibiliser can be considered as the so-called critical micelle concentration (CMC) above which micelles of the copolymer are formed in the bulk phase, which is highly undesirable. Emulsification master curves were obtained by plotting the reduced domain size as a function of EPM-g-MA for the different blend compositions. This was explained based on the interfacial area occupied by the compatibiliser molecule at the blend interface. The experimental results were compared with the current compatibilisation theories. The phase morphology development was studied as a function of the mixing time in the presence and absence of compatibiliser. The influence of reactive compatibilisation on phase inversion and the co-continuous nature of the blends was also investigated. Finally the stability of the blend morphology was analysed by high temperature isothermal annealing in the presence and absence of compatibiliser