Styrene-maleic Anhydride Copolymer Research Articles

Influence of Styrene–Maleic Anhydride Copolymers on the Stability of Quinacridone Red Pigment Suspensions

In order to study the influence of styrene–maleic anhydride (SMA) copolymer on the stability and flocculation of quinacridone red pigment suspension, a series of copolymers with different structures were synthesized by changing the ratio of maleic anhydride to styrene and the amount of initiator. The SMA copolymer with an intrinsic viscosity η of 0.2438 L g−1 should have the best dispersing ability. Moreover, the stability of quinacridone red pigment suspensions was compared through ζ‐potential measurements and a sedimentation test, wherein the pH (from 3 to 10) and the ionic strength (from 0 to 0.05 mol dm−3) of the system were varied over a wide range. The SMA copolymer studied could give a considerable enhancement of the absolute ζ‐potential of the quinacridone pigment particles if the pH and the ionic strength of the system were well controlled. The quinacridone pigment suspension maintained stability when the pH of the system was above 7 and the ionic strength of the system was below 0.001 mol dm−3.

Synergistic effect of dual rubber system in toughening styrene maleic anhydride copolymers

Styrene maleic anhydride (SMA) copolymers were toughened by blending with two distinctly different rubber modifiers: styrene-butadiene-styrene (SBS) block copolymer and methacrylated butadiene-styrene emulsion-made graft copolymer (MBS). The modifiers were used both individually and in combination for the examination of their roles in toughening SMA. SMA was miscible with poly(methylmethacrylate) shell of MBS, whereas it was partially miscible with the polystyrene (PS) phase of SBS. When 40–50% of SBS was used in blends, the PS phase of SBS became immiscible with SMA. SBS did not improve the Izod impact strength of SMA appreciably. A prominent synergistic toughening effect was experimentally observed when SBS and MBS were used in combination in brittle SMA. This effect may be attributed to the fact that the large SBS particles initiate crazes and small MBS particles with good adhesion to SMA matrix improve the ligament thickness, which may play a critical role in craze growth and termination. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2260–2267, 2003

Compatibilization of nylon 6/liquid crystalline polymer blends with three types of compatibilizers

AbstractPolyblends of nylon 6 and liquid crystalline polymer (LCP) (Vectra A 950) are immiscible and highly incompatible, with resultant poor interfacial adhesion, large phase domains, and poor mechanical properties. In the present work, compatibilizing strategies are put forward for blends containing nylon and LCP. Effects of three types of compatibilizers, including ionomer Zn–sulfonated polystyrene (SPS), reactive copolymer styrene–maleic anhydride (SMA), functional grafted copolymers—polypropylene grafted glycidyl methacrylate (PP‐g‐GMA) and polypropylene grafted maleic anhydride (PP‐g‐MAH)—are studied in the aspects of morphology and dynamic mechanical behavior. The addition of compatibilizers decreases the domain size of the dispersed phase and results in improved interfacial adhesion between LCP and matrix. The compatibilization mechanism is discussed by way of diffuse reflectance Fourier transform spectroscopy (DRIFT), showing the reaction between compatibilizers and matrix nylon 6. Mechanical properties are improved by good interfacial adhesion. The contribution of SMA to mechanical properties is more obvious than that of Zn‐SPS and grafted PPs used. The blending procedure is correlated with the improvement of mechanical properties by the addition of compatibilizer. Two‐step blending is demonstrated as an optimum method to obtain composites with better mechanical properties as a result of a greater chance for LCP to contact the compatibilizer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1452–1461, 2003

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.

Microcapsules from styrene–maleic anhydride copolymers: study of morphology and release behavior

Both microcapsules and matrix particles were formed by interfacial polycondensations of styrene–maleic anhydride (SMA) copolymers and polyamines in oil-in-water (o/w) suspension systems. The morphologies formed depended on composition, molecular weight and loading of the styrene–maleic anhydride copolymer, as well as on amine partitioning and on the rate of amine addition. The organic phase was comprised of mixtures of ethyl acetate (good solvent) and dodecyl acetate (non-solvent). Dodecyl acetate served both as co-solvent, and as a model compound for controlled release of insect sex pheromones. The dependence of the release characteristics of the particles on the morphology is discussed as well.

Blends of styrene-butadiene-styrene triblock copolymer with random styrene-maleic anhydride copolymers

Blends of styrene-butadiene-styrene triblock copolymer (SBS) with random styrene-maleic anhydride copolymers (PS-co-MA), having different MA content, were prepared in a Brabender Plastigraph mixer. The presence of polystyrene (PS) blocks in the SBS copolymer and the high styrene content (93 and 86 wt.-%, respectively) in the two kinds of used PS-co-MA samples afforded a good compatibility between the PS phases of the two polymers. On the other hand, the presence of polar anhydride groups allows a net improvement of the thermal properties of the polystyrene phase of the blends as shown by differential scanning calorimetry (DSC) analysis. In addition, the dynamic behavior of the blends, as highlighted by dynamic thermo-mechanical analysis (DMTA), shows in all cases a “stiffening” of the material in comparison to original SBS. Preliminary experiments aimed to convert, directly in the mixer, the anhydride groups into the corresponding zinc salt allowed only a partial neutralization. Both DSC and scanning electron microscopy (SEM) indicate that the reaction is not complete under the used experimental conditions. Tg against PS-co-MA content for SBS/PS-co-MA blends.

Water-Blown Expandable Polystyrene. Improvement of the Compatibility of the Water Carrier with the Polystyrene Matrix by in Situ Grafting

The compatibility of starch with the polystyrene matrix in the synthesis of water-blown expandable polystyrene (WEPS) was improved by making use of maleic anhydride. The foam morphology on the contrary is significantly changed after pre-expansion as the content of maleic anhydride is increased. It has been found that starch is grafted during the polymerization with styrene-maleic anhydride copolymer. Partial immscibility of polystyrene matrix and styrene-maleic anhydride grafts formed at higher concentrations of maleic anhydride causes the agglomeration of starch. Consequently, water, as the blowing agent, cannot be finely dispersed in the matrix, which is the reason of the irregular foam morphology. Different methods for the improvement of the compatibilization are discussed.

A proton NMR study of the effect of a new intravasal injectable male contraceptive RISUG on seminal plasma metabolites.

Nuclear magnetic resonance (NMR) spectroscopy was used to quantify citrate, glucose, lactate, glycerophosphorylcholine and choline in seminal plasma from subjects injected with a new male contraceptive RISUG, a copolymer of styrene maleic anhydride dissolved in dimethyl sulphoxide, and in seminal plasma from normal ejaculates. No significant difference in the concentration of citrate was observed between the groups, indicating that the prostate is not affected by the contraceptive. The concentrations of glucose, lactate, glycerophosphorylcholine and choline were significantly lower (P < 0.01) in subjects injected with RISUG compared with controls. In addition, metabolite ratios such as choline:citrate, citrate:lactate, choline:lactate and glycerophosphorylcholine:choline were calculated. Citrate:lactate and glycerophosphorylcholine:choline ratios were significantly lower in RISUG-injected subjects than in controls (P < 0.01), thereby indicating the occurrence of partial obstructive azoospermia. The most important finding of the present study was that the intervention of RISUG in the vas deferens even for a period as long as 8 years is absolutely safe and does not lead to prostatic diseases.

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

AbstractWaste 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 &amp; Sons, Inc. J Appl Polym Sci 80: 2593–2599, 2001

Viscoelastic properties of reactive and non‐reactive blends of ethylene‐methyl acrylate copolymers with styrene‐maleic anhydride copolymer

AbstractThe effects of compatibilizing reactions on the viscoelastic properties and morphology of ethylene‐methyl acrylate copolymers were studied. Potentially reactive blends of styrene‐maleic anhydride copolymer (SMAH) and a terpolymer of ethylene/methyl acrylate/glycidyl methacrylate (E‐MA‐GMA) were compared with a non‐reactive blend of SMAH and an ethylene/methyl acrylate (E‐MA) copolymer with similar rheological properties. Melt mixing was carried out in a batch mixer and in a co‐rotating twin screw extruder. The morphology of the reactive blends showed smaller domain sizes than the non‐reactive blends, and the viscoelastic properties of the blends were very different. The storage and loss moduli and the complex viscosity of the reactive blends were greater than those of non‐reactive blends. The reactive blends had a higher zero shear viscosity, plateau modulus and mean relaxation time than their non‐reactive counterparts, indicating a higher degree of melt elasticity. The melt elasticity was maximum at 25% functionalized ethylene‐methyl acrylate concentration.

Compatibilization and characterization of blends of styrene-maleic anhydride copolymer with modified polyethylenes

Potentially reactive blends of styrene–maleic anhydride (SMAH) with ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) and nonreactive blends of SMAH with ethylene/methyl acrylate (E-MA) were produced in a Brabender batch mixer and in a corotating twin-screw extruder. The products were characterized in terms of rheology, morphology, and mechanical properties to understand the reaction characteristics between anhydride/epoxy functional groups. Storage modulus, G′, loss modulus, G″ and complex viscosity, η* of the reactive blends were higher than those of nonreactive ones. At 25% E-MA-GMA content, maximum in η* was obtained for the reactive blends. The reactive blends showed finer morphology than the nonreactive ones at all concentrations studied. Mechanical characterization showed that reactive SMAH/E-MA-GMA blends had higher tensile strength, % strain at break, and tensile modulus than the nonreactive blends for all corresponding modified polyethylene contents. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 790–797, 2001

Thermal degradation of copolymers of styrene with dicarboxylic acidsI. Alternating styrene-maleic acid copolymer

An alternating styrene-maleic anhydride copolymer was hydrolysed to obtain styrene-maleic acid copolymer. The degradation of the product was studied and the thermal stability of hydrolysed copolymer compared with that of parent copolymer. It was found that alternating styrene-maleic acid copolymer degraded in three stages. FTIR spectra of heated film of copolymer as well as mass spectrometry of volatile products of the decomposition indicate that dehydration is the main reaction, which takes place at the first stage of degradation. However, the decomposition is not only the simple regeneration of the maleic anhydride units. Heating of the styrene-maleic acid copolymer to 250 °C causes an increase of its glass temperature in comparison to T g of the parent copolymer. During heating at 140 °C the hydrolysed styrene-maleic acid copolymer loses its solubility in polar solvents, presumably due to crosslinking. The volatile products of the last two stages of degradation were studied by mass spectrometry.

Self-assembly films from diazoresin and carboxy-containing polyelectrolytes

Multilayer films from diazoresin (I) and poly(sodium acrylate) (II) or a hydrolyzed maleic anhydride–styrene copolymer (III) have been fabricated on mica. During the fabrication process the absorbance of the film at 380 nm, which is the characteristic absorption of the diphenylamine 4-diazonium group of I, increases about 0.033 for each fabrication cycle. This means that the thickness of the film increases regularly. Under irradiation with UV light or heating, following the decomposition of the diazonium group, the ionic bond in the film structure converts to a covalent bond; this conversion was preliminarily verified by FTIR spectrum analysis. The stability of the different films (irradiated or unirradiated) was determined by UV-vis spectroscopy and the results show that the resistance of the film to etching by polar solvents increases significantly after bond conversion.

Lithium gel polyelectrolytes based on crosslinked maleic anhydride–styrene copolymer

The effect of various solvents, lithium salts and Lewis acids on the conductivity of crosslinked lithium carboxylates resulting from the modification of maleic anhydride copolymers with styrene has been studied. It was found that in the presence of BF 3 and polar solvents such as dialkyl sulfoxides or propylene carbonate polyelectrolytes can be obtained in the form of dimensionally stable membranes of ambient temperature conductivity of ≈10 −3–10 −4 S·cm −1. IR studies demonstrate a strong interaction between BF 3 and carboxylic anions leading to a greater mobility of Li + cations. The passivation phenomena at the lithium–gel polyelectrolyte interface for selected systems were examined by means of the impedance spectroscopy. It was found that the passivation layers could be formed in these systems both on the electrode and the polymeric membranes. The passivation process is strongly inhibited in the systems containing BF 3.

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

Processing and characterization of reactive polystyrene/hyperbranched polyester blends

Newly developed hyperbranched polyols (HBPs) possess a compact, highly branched, three-dimensional (3D) structure, which has a high density of functional end groups and inherently low viscosity. The combination of these two properties, low viscosity and high reactivity, makes HBP polymers attractive candidates for reactive polymer blending. The HBP additives are able to behave as lubricants during processing and as self-compatibilizing toughening agents in the final blend formulation. In this work, we have studied a series of blends of hyperbranched polyester with high molecular weight polystyrenes. The processability and compatibility in the blends were investigated as a function of volume fraction of the HBP added and reactivity of the matrix phase. We find, through processing and rheological studies, that HBPs are extremely effective processing aids. A significant drop in the blend viscosity occurs immediately on addition of HBP, even at levels as low as 2vol.%. Characterization including microscopy, thermal analysis and Fourier transform infrared spectroscopy (FTIR) indicates that the HBP forms immiscible blends with polystyrene and styrene maleic anhydride (SMA) copolymers. A significant degree of compatibilization occurs in the reactive systems, as evidenced by shifts in the thermal transitions of the HBP phase, and by morphology refinement observed by electron microscopy. The degree of compatibilization in the blends was found to increase with SMA reactivity.

Studies on Surface Sizing Agents

Recently. ink-jet printers are widely used in offices and homes, and the consumption of PPC increases considerably. At the same time, the use of DIP as recycled fibers has increased significantly over the past few years, driven by mix of factors including environmental concerns and economic consideration. The fraction of DIP in PPC continues to increase, therefore the role of surface sizing agents are expected to become more important.Styrene acrylate copolymers (I) and styrene maleic anhydride copolymers (II) are the most common for surface sizing applications. But these effects are not sufficient to improve ink-jet printability for DIP-based paper. In contrast to the polymers (I) and (II), olefin maleic anhydride copolymers (III) are ineffective in aqueous ink acceptability for common papers. On the other hand, in case of application for DIP-based paper, the polymer (III) shows superior sizing performance. Then we have interested in such characteristics of olefin and tried to investigate the relationships between hydrophobicity of the polymers (III) and ink-jet printability.

Rheology of a miscible blend of SAN and SMA

We present results of oscillatory shear rheology experiments on miscible blends of commercial styrene-acrylonitrile (SAN) and styrene-maleic anhydride (SMA) copolymers. We find that this blend system upholds the empirical time-temperature superposition principle. We compare the thermorheological behavior in this system with other blends, on which oscillatory shear data have been published in the literature. We show that thermorheological behavior in these blends is indeed comparable to other known thermorheologically simple blends. Thermorheological simplicity in this blend is nicely anticipated by a thermorheological phase diagram in the parameter space of dynamic asymmetry and free volume, which we have recently proposed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1245–1249, 2000

Compatibilizing effect of styrene-maleic anhydride copolymer on the properties of polyamide-6/liquid crystalline copolyester composites

Liquid crystalline polymer–polyamide-6 (LCP/PA6) composites containing 20 wt % LCP content were compatibilized by a random styrene–maleic anhydride copolymer (RSMA). The blending was performed via extrusion followed by injection molding. The LCP employed was a commercial copolyester, Vectra A950. The dynamic mechanical (DMA), rheological, thermal, and mechanical properties as well as the morphology of the composites were studied. The DMA and rheological results showed that RSMA is an effective compatibilizer for LCP/PA6 blends. The mechanical measurements showed that the stiffness, tensile strength, and toughness of the in situ composites are generally improved with increasing RSMA content. However, these mechanical properties deteriorated considerably when RSMA content was above 10 wt %. The drop-weight dart impact test was also applied to analyze the toughening behavior of these composites. The results show that the maximum impact force (Fmax) and crack-initiation energy (Einit) tend to increase with increasing RSMA content. From these results, it appeared that RSMA prolongs the crack-initiation time and increases the energies for crack initiation and impact fracture, thereby leading to toughening of LCP/PA6 in situ composites. Finally, the correlation between the mechanical properties and morphology of the blends is discussed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1964–1974, 2000

Functional polymers for colloidal applications. XIV. Syntheses of styrene-maleic anhydride copolymers with different charges and their ability to disperse kaolinite particles

Four kinds of styrene/maleic–anhydride (SMA) copolymer-derived dispersants with different charged forms were synthesized and characterized with 1H-NMR. These four different dispersants contained carboxylic acid groups and exhibited characteristics indicative of anionic, cationic, zwitterionic, or nonionic surfactants as pH was changed. The charge properties of these copolymers changes with pH, and their ability to disperse clay particles under low and high pH were assessed by measuring viscosity or sedimentation, as well as Scanning Electron Microscopy (SEM). The results showed that the dispersing abilities are functions of pH of the system. It was found that SMA-N [Poly(styrene-co-β-N,N-dimethylpropylamino) maleic acid, sodium salt)] exhibits the best dispersing ability, the fastest rate of sedimentation, and the smallest sedimentation volume at pH = 2, and SMA-Na [poly(styrene-co-maleic acid, disodium salt)] exhibits the better dispersing ability at pH = 7 and 12. In addition, the aggregation behavior of the dispersants characterized by fluorescence spectroscopy revealed that the degree of aggregation for all dispersants at high concentration increases in the order: SMA-Na < SMA-B [poly(styrene-co-B-imino-propyl-N-trimethylammonium acetate) maleic acid, disodium salt)] < SMA-N < SMA-Q [poly(styrene-co-β-imino-propyl-N-trimethylammonium sulfate) maleic acid, sodium salt)]. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 592–602, 2000