Styrene-maleic Anhydride Copolymer Research Articles

Microstructure manipulation in PVDF/styrene-maleic anhydride copolymer composite membranes: Effects of miscibility on the phase separation

Amphiphilic copolymers have increasingly attracted researchers’ attention to produce the hydrophilic and antifouling polymeric membranes. However, few studies has been reported on systematic manipulation of matrix miscibility to control the membrane microstructure during the nonsolvent induced phase separation (NIPS). Herein, a facile method is brought forward to investigate the effects of miscibility on the structure and performance of the membranes. Through the transformation of styrene-maleic anhydride copolymer (SMA) into sodium styrene-maleic anhydride copolymer (SMANa), a homogeneous and transparent dope solution was successfully prepared. Next, the crescent pores and spherical particles in the PVDF/SMA membrane were eliminated to achieve the uniformly porous PVDF/SMANa membranes by the exchange of nonsolvent and solvent components. Importantly, SMANa could segregate at the external surface and internal pore walls as SMA to enhance the hydrophilicity and antifouling properties of the membranes. Subsequently, by optimizing the dope solution composition and coagulation bath temperature, PVDF/SMANa ultrafiltration membranes exhibited the pure water flux of 1014 L/m2h and the rejection to BSA of 98.9%. These results outperformed previously reported ones for similar PVDF composite membranes. Significantly, this strategy can be applied to the large-scale manufacture of membranes.

Enhanced Piezoelectric Properties of Poly(Vinylidenefluoride-Co-Trifluoroethylene)/Carbon-Based Nanomaterial Composite Films for Pressure Sensing Applications

In this study, heat and polarization treatments were applied to poly(vinylidenefluoride-co-trifluoroethylene (PVDF-TrFE) films to improve their crystallinity and piezoelectric effect. Carbon-based nanomaterials (CBNs) of multiple dimensions (i.e., modified zero-dimensional (0D) carbon black (OCB), one-dimensional (1D) modified carbon nanotubes (CNT–COOH) and two-dimensional (2D) graphene oxide (GO)) were added to the copolymer to study the effects of different CBN dimensions on the crystallinity and piezoelectric effect of PVDF-TrFE films. Additionally, amphiphilic polymeric dispersants were added to improve the dispersibility of CBNs; the dispersant was synthesized by the amidation, and imidization reactions of styrene-maleic anhydride copolymer (SMAz) and polyoxyalkylene amine (M1000). Polymer solutions with different ratios of CBN to dispersant (z = 10:1, 5:1, 1:1, 1:5, 1:10) were prepared. The enhanced dispersibility enabled the fluorine atoms in the PVDF-TrFE molecular chain to more efficiently form hydrogen bonds with the –COOH group in the CBN, thereby increasing the content of the β crystal phase (the origin of the piezoelectric effect) of the film. Therefore, the resulting film exhibited a higher output voltage on the application side and better sensitivity on the sensing element. The addition of CNT–COOH and polymeric dispersants increased the β-phase content in PVDF-TrFE from 73.6% to 86.4%, which in turn raised the piezoelectric coefficient from 19.8 ± 1.0 to 26.4 ± 1.3 pC/N. The composite film-based pressure sensor also exhibited a high degree of sensitivity, which is expected to have commercial potential in the future.

Fabrication of highly permeable PVDF loose nanofiltration composite membranes for the effective separation of dye/salt mixtures

The separation of dyes and salts is very challenging in regards to treating high salinity textile wastewater. To effectively dispose dye/salt mixtures, it has become urgent to develop highly permeable and antifouling nanofiltration membranes. Herein, a novel loose nanofiltration membrane was fabricated by combining blending with interfacial polymerisation. Polyvinylidene fluoride (PVDF)/styrene-maleic anhydride (SMA) copolymer membranes with uniform microstructures were achieved via phase inversion by controlling the miscibility. Numerous carboxyl groups were gathered on the surface due to the amphiphilic SMA segregation during the membrane formation. Carboxylated carbon nanotubes (CNT-COOH) were used to further tune the membrane microstructures and promote the carboxyl groups segregation onto the surface. Ultimately, polyethylenimine (PEI) and triethanolamine (TEA) were co-deposited on the membrane surface by the amidation reaction and hydrogen bonding to form a loose structure. The optimized membrane exhibited high dye rejections to Congo red (99.9%), methyl blue (96.7%), acid fuchsin (96.1%), and low salt rejections to NaCl (1.7%), MgCl2 (4.5%), MgSO4 (1.2%). Significantly, it possessed a permeate flux of up to 251.6 L/m2·h·bar during the dye/salt mixtures filtration. Moreover, the optimized membrane also performed excellent antifouling properties toward proteins and dyes. Overall, this work provides a promising loose nanofiltration membrane for textile wastewater treatment.

Evaluation of the prepared amino styrene derivatives for the uranium recovery from sulphate media

ABSTRACT Low-cost polymer styrene maleic anhydride copolymer has been modified by the reaction with ethylene diamine, hexamethylene diamine and dodecyl diamine in aqueous media. The prepared derivatives have been characterised by elemental analysis, spectral analysis and thermal analysis. The derivatives were used for the adsorption of uranyl ions from sulphate media. The adsorption was investigated at different pH, time, uranium concentration and temperature. The adsorption kinetics was found to follow a pseudo-second-order model. The adsorption isotherm was found to follow the Langmuir model better than the Freundlich one. The experimental studies confirmed that the prepared modified copolymers are good candidates for U(VI) ions adsorption from sulphate media. The adsorption data have shown that the styrene maleic anhydride dodecyl diamine has an adsorption efficiency reaching 97.75% with a capacity of 61.35 mg g−1.

Enhanced performances of chlorinated polyvinyl chloride (CPVC) ultrafiltration membranes by styrene-maleic anhydride copolymer

To enhance the performances of the CPVC ultrafiltration membranes, herein, styrene-maleic anhydride copolymer (SMA), an amphiphilic copolymer, was used to blend with CPVC to adjust the microstructures of membranes. The pure CPVC and SMA/CPVC composite ultrafiltration membranes were prepared by a non-solvent-induced phase inversion process. It has been proved that SMA and CPVC were partially compatible according to the rheological behavior of casting solution, DSC, FT-IR and SEM. SMA changed the phase separation mechanism and the pore structure of the composite membranes, and significantly increased the porosity. According to the results of ATR-FTIR, EDS and XPS analysis, intact anhydride groups existed on the surface of the composite membranes, which enhanced the permeability of membranes. The SMA/CPVC composite ultrafiltration membranes with 2 wt% SMA exhibited superior pure water flux (459.85 L/m2·h), protein rejection (97.2%) and permeability flux (140.69 L/m2·h) compared with the neat CPVC membrane (248.97 L/m2·h, 74.5%, 74.14 L/m2·h, respectively) at 0.1 MPa. Moreover, the flux recovery ratio increased from 55.32% to 92.68% and irreversible fouling index decreased from 42.51% to 5.00%. Importantly, the antifouling mechanism of the SMA/CPVC ultrafiltration membrane was discussed in detail.

Intelligent adjustment of light-to-thermal energy conversion efficiency of thermo-regulated fabric containing reversible thermochromic MicroPCMs

In this study, a series of reversible thermochromic MicroPCMs (RT-MPCMs) were synthetized through encapsulating ternary thermochromic mixtures via in-situ polymerization, and presented outstanding stable light-to-thermal conversion capability (η = 86.9%), excellent latent thermal energy storage-release performance (ΔHm = 171.9 J·g−1, ΔHc = 171.4 J·g−1) and color-changing monitoring the states of energy storage or release, satisfactory thermal reliability and thermal cyclic durability. The RT-MPCMs with spherical integrity, smooth surface morphology and obvious core-shell microstructure were obtained by emulsifying with the solution (1.2 wt%–3.1 wt%) of sodium salt of styrene maleic anhydride copolymer. The crystallization of RT-MPCMs was mainly affected by the structure of methyl stearate (MeS). The crystallization changes and coloration inside capsules was observed real-timely via microscope at different temperature ranging from 1 to 40 °C. In addition, based on these excellent performances, the actual application value of RT-MPCMs was further discussed. The narrow-disperse composite macrocapsules containing RT-MPCMs was prepared and further encapsulated by real non-woven fabrics substrate for the intelligent adjustment-based garment to research practical value in thermoregulation field. The experimental results show that it can absorb the latent thermal energy from the skin or environmental heat, which is beneficial for keeping constant and comfortable body surface temperature, and showing great application value in the fields of temperature regulation and thermal management.

Thorium(IV) Preconcentration by Chelate-Forming Adsorbents Based on a Maleic Anhydride–Styrene Copolymer

The adsorption and complexing properties of modified adsorbents based on a maleic anhydride–styrene copolymer with respect to thorium(IV) ions were studied. Adsorbents containing fragments of 2‑amino-4-chloro-6-sulfophenol and 2,4-diamino-6-phenyltriazine-1,3,5 are used. The main quantitative characteristics of the adsorption of thorium are determined, and the optimal adsorption conditions are found. The concentration factor is not lower than 200 in extraction from 20 mL of a solution by 30 mg of the adsorbent. The recovery of radioactive thorium exceeds 95%. The developed procedure was applied to determine thorium(IV) in soil contaminated with oil.

Modification of polystyrene maleic anhydride for efficient energy storage applications

The development of new energy storage devices has been gaining momentum in the wake of the energy crisis faced worldwide. New materials have been tried and tested and efforts have been made to implement these materials to the commercial arena. Conducting polymers have been used and new polymeric structures have been designed in this respect. Here, we have modified styrene maleic anhydride (SMA) copolymer with two different moieties, i.e. 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) and 4,4-diaminodiphenylmethane (DDM) with an aim to study their electrochemical characteristics in details. The modifications were expected to greatly improve the electrochemical performance of an otherwise feebly conducting polymer. Both the modified copolymers were characterised using UV-visible and FTIR spectroscopic techniques and scanning electron microscopy. Their electrochemical properties were studied using cyclic voltammetry, chronopotentiometry and AC impedance techniques. These materials exhibited a significant enhancement in their specific capacitance when compared with SMA. SMA represents a specific capacitance of 24.5 F g−1 whereas AMT-modified copolymer SMA-1 exhibited a specific capacitance of 149 F g−1 and DDM-modified copolymer SMA-2 exhibited a specific capacitance of 124.45 F g−1. Thus, the results clearly indicated a considerable increase in the values of capacitance of SMA after the modification was performed.

Properties of Styrene-Maleic Anhydride Copolymer Compatibilized Polyamide 66/Poly (Phenylene Ether) Blends: Effect of Blend Ratio and Compatibilizer Content.

Two different blend ratios of polyamide 66 (PA66) and poly (2,6-dimethyl-1,4-phenylene ether) (PPE) (60/40 and 40/60 w/w) were produced via melt mixing. A styrene–maleic anhydride copolymer (SMA) was utilized at various contents from 2.5–15 wt% to compatibilize the immiscible blend system. The influence of SMA content and blend ratio was investigated based on (thermo-) mechanical and morphological properties of the PA66/PPE blends. Correlations between the interaction of SMA with the blend partners were established. For 60/40 blends, a droplet-sea morphology was visualized by transmission electron microscopy, wherein no major changes were seen upon SMA addition. In the case of 40/60 blends, strong coalescence was found in the binary blend. Up to 5 wt% SMA, the coalescence was inhibited by the interfacial activity of SMA, whereas 10 wt% SMA initiated a disperse-to-co-continuous transition, which was completed at 15 wt% SMA. An enhancement of tensile properties was achieved for all blends possessing SMA, where the maximum concentration of 15 wt% resulted in the highest elongation at break and tensile strength values. The relative improvement of the tensile properties was higher with the PPE-rich blend (40/60) which was attributed to a partial emulsification of the PPE phases forming a bimodal PPE domain size distribution with nano-droplets in the range of 60–160 nm.

CD81 extracted in SMALP nanodiscs comprises two distinct protein populations within a lipid environment enriched with negatively charged headgroups

Tetraspanins exert a wide range of cellular functions of broad medical importance. Despite this, their biophysical characteristics are incompletely understood. Only two high-resolution structures of full-length tetraspanins have been solved. One is that of human CD81, which is involved in the infectivity of human pathogens including influenza, HIV, the malarial Plasmodium parasite and hepatitis C virus (HCV). The CD81 crystal structure identifies a cholesterol-binding pocket, which has been suggested to be important in the regulation of tetraspanin function. Here we investigate the use of styrene-maleic anhydride co-polymers (SMA) for the solubilisation and purification of CD81 within a lipid environment. When CD81 was expressed in the yeast Pichia pastoris, it could be solubilised and purified using SMA2000. This SMALP-encapsulated CD81 retained its native folded structure, as determined by the binding of two conformation-sensitive anti-CD81 antibodies. Analysis by size exclusion chromatography revealed two distinct populations of CD81, only one of which bound the HCV glycoprotein, E2. Optimization of expression and buffer conditions increased the proportion of E2-binding competent CD81 protein. Mass spectrometry analysis indicated that the lipid environment surrounding CD81 is enriched with negatively charged lipids. These results establish a platform to study the influence of protein-lipid interactions in tetraspanin biology.

Solubilization and Stabilization of Membrane Proteins by Cycloalkane-Modified Amphiphilic Polymers.

Membrane proteins (MPs) need to be extracted from biological membranes and purified in their native state for most structural and functional in vitro investigations. Amphiphilic copolymers, such as amphipols (APols), have emerged as very useful alternatives to detergents for keeping MPs water-soluble under their native form. However, classical APols, such as poly(acrylic acid) (PAA) derivatives, seldom enable direct MP extraction. Poly(styrene maleic anhydride) copolymers (SMAs), which bear aromatic rings as hydrophobic side groups, have been reported to be more effective extracting agents. In order to test the hypothesis of the role of cyclic hydrophobic moieties in membrane solubilization by copolymers, we have prepared PAA derivatives comprising cyclic rather than linear aliphatic side groups (CyclAPols). As references, APol A8-35, SMAs, and diisobutylene maleic acid (DIBMA) were compared with CyclAPols. Using as models the plasma membrane of Escherichia coli and the extraction-resistant purple membrane from Halobacterium salinarum, we show that CyclAPols combine the extraction efficiency of SMAs with the stabilization afforded to MPs by classical APols such as A8-35.

Properties of Styrene-Maleic Anhydride Copolymer Compatibilized Polyamide 66/Poly (Phenylene Ether) Blends: Effect of Maleic Anhydride Concentration and Copolymer Content.

Polyamide 66 (PA66)/poly (2,6-dimethyl-1,4-phenylene ether) (PPE) blends with a ratio of 50/50 (w/w) were produced by a twin-screw compounder. The immiscible blends were compatibilized using two different styrene–maleic anhydride copolymers (SMA) with a low (SMAlow) and a high (SMAhigh) maleic anhydride (MA) concentration of 8 and 25 wt%, respectively. Furthermore, the SMA content was varied from 0 to 10 wt%. The influence of MA concentration and SMA content on the morphological and thermomechanical properties of PA66/PPE blends was investigated. Herein, we established correlations between the interfacial activity of the SMA with blend morphology and corresponding tensile properties. A droplet-sea to co-continuous morphology transition was shown by scanning electron microscopy to occur between 1.25 and 5 wt% in the case of SMAhigh. For SMAlow, the transition started from 7.5 wt% and was still ongoing at 10 wt%. It was found that SMAlow with 10 wt% content enhanced the tensile strength (10%) and elongation at break (70%) of PA66/PPE blends. This improvement can be explained by the strong interfacial interaction of SMAlow within the blend system, which features the formation of nanoemulsion morphology, as shown by transmission electron microscopy. Very small interdomain distances hinder matrix deformations, which forces debonding and cohesive failure of the PPE phase as a “weaker” main deformation mechanism. Due to a lack of interfacial activity, the mechanical properties of the blends with SMAhigh were not improved.

Biocompatible supercapacitor electrodes using green synthesised ZnO/Polymer nanocomposites for efficient energy storage applications

In the era of rapid decline of renewable sources of energy, novel supercapacitor materials are essential to provide impetus to the growing energy demands arising from the commercialization of technology towards an electric-powered future which aims at both efficient and sustainable use of energy. The inspiration is to develop materials that effect specific applications without causing any damage to the environment. The use of inherently non-conducting but biocompatible polymers that can be functionally modified are thus imperative in this respect. Here, styrene maleic anhydride (SMA) copolymer has been structurally modified with a thiadiazole moiety along with the incorporation of green synthesized ZnO nanoparticles to prepare a polymer nanocomposite. The green synthesized ZnO nanoparticles display a flake-like structure with a size of about 20 nm. UV, FT-IR and XRD analyses validates the incorporation of ZnO in to the polymer matrix to form the polymer nanocomposite. Satisfactory supercapacitor behaviour with a specific capacitance of 268.5 F g−1 at 0.1 A g−1 is estimated for the polymer nanocomposite which is larger than ZnO nanoparticles and the bare polymer. It is demonstrated that the innate conductivity of the SMA copolymer is enhanced upon modification. The materials also exhibit good cycling stability with maximum capacitance retention. The biocompatibility of the nanocomposites has been established from the preliminary cell viability studies performed on 3T6 mouse fibroblast cells. The developed material shows great promise to provide a green alternative to existing supercapacitors.

Preparation of porous antibacterial polyamide 6 (PA6) membrane with zinc oxide (ZnO) nanoparticles selectively localized at the pore walls via reactive extrusion.

Antibacterial polymer membranes have been widely used in many fields of our daily life. In this study, porous PA6 membrane with ZnO nanoparticles attaching on to the surface of inner pore walls is prepared. Firstly, SMA (styrene maleic anhydride copolymer) is used to graft onto the surface of ZnO nanoparticle in DMF (dimethylformamide). Then the pre-treated ZnO nanoparticles (ZnO-SMA) are added into SEBS (Styrene-ethylene-butylene-styrene copolymer)/PA6 (60/40 wt/wt) blends with co-continuous morphology. The effects of SMA molecular structure (molecular weight and maleic anhydride content) used for ZnO-SMA nanoparticles on their dispersion states in SEBS/PA6/ZnO-SMA nanocomposites are investigated. When SMA3 (MAH=8wt%, Mn=250,000gmol-1), which has relatively higher molecular weight and lower MAH content, is used as the pre-treating agent, ZnO-SMA3 nanoparticles tend to be dispersed at the phase interface in SEBS/PA6/ZnO-SMA nanocomposites. However, when SMA2 (MAH=23wt%, Mn=110,000gmol-1) with relatively lower molecular weight and higher MAH content is used, no ZnO-SMA2 nanoparticles locate at the interface but stay within PA6 phase. Porous PA6 membranes are obtained by selectively etching SEBS phase out with xylene. It can be found that porous PA6 membrane containing ZnO-SMA3 nanoparticles still exhibits much better antibacterial property (R=3.76) toward S. aureus even at a very low ZnO content (0.5wt%). This result should be ascribed to almost all the ZnO-SMA3 nanoparticles being exposed to the surface of inner pore walls of PA6 membrane. This work proposes an effective method to prepare porous polymer membrane with functional nanoparticles selectively located at the inner pore walls.

Chitosan based polyelectrolyte complexes development for anionic and cationic dyes adsorption

As huge amounts of hazardous dyes from different industries are causing water pollution, the removal of these compounds from a process or waste effluents becomes a crucial environmental importance. The adsorption method has been found to handle large quantities without the formation of hazardous substances. In spite of the efficiency of the adsorption technique, the high cost of the adsorbent materials is a stumbling block for large scale applications. An eco-friendly, low-cost and efficient adsorbent has been prepared for wastewater management. Hydrolyzed and sulphonated styrene maleic anhydride copolymers, were mixed with chitosan to form nano-polyelectrolyte complexes. Structure, particle size and thermal behavior of the complexes were investigated by spectral and thermogravimetric analyses. The hydrolyzed and sulphonated styrene maleic anhydride chitosan complexes (H-SMA-CS and S-SMA-CS) were examined for the adsorption of Congo red and Maxilon blue as anionic and cationic dyes, respectively. The experimental data of adsorption were found to fit the pseudo-second-order kinetic. The maximum adsorption capacities of Congo red were 234 and 116 mg/g where those of Maxilon blue were 702 and 1830 mg/g on S-SMA-CS and H-SMA-CS, respectively. The isotherm results were well fitted by the Freundlich isotherm.

Simple Derivatization of RAFT-Synthesized Styrene-Maleic Anhydride Copolymers for Lipid Disk Formulations.

Styrene-maleic acid copolymers have received significant attention because of their ability to interact with lipid bilayers and form styrene-maleic acid copolymer lipid nanoparticles (SMALPs). However, these SMALPs are limited in their chemical diversity, with only phenyl and carboxylic acid functional groups, resulting in limitations because of sensitivity to low pH and high concentrations of divalent metals. To address this limitation, various nucleophiles were reacted with the anhydride unit of well-defined styrene-maleic anhydride copolymers in order to assess the potential for a new lipid disk nanoparticle-forming species. These styrene-maleic anhydride copolymer derivatives (SMADs) can form styrene-maleic acid derivative lipid nanoparticles (SMADLPs) when they interact with lipid molecules. Polymers were synthesized, purified, characterized by Fourier-transform infrared spectroscopy, gel permeation chromatography, and nuclear magnetic resonance and then used to make disk-like SMADLPs, whose sizes were measured by dynamic light scattering (DLS). The SMADs form lipid nanoparticles, observable by DLS and transmission electron microscopy, and were used to reconstitute a spin-labeled transmembrane protein, KCNE1. The polymer method reported here is facile and scalable and results in functional and robust polymers capable of forming lipid nanodisks that are stable against a wide pH range and 100 mM magnesium.

A carbon nanotube reinforced functionalized styrene–maleic anhydride copolymer as an advanced electrode material for efficient energy storage applications

In the wake of the global energy crisis, innovative materials are being developed to alleviate the energy shortage by utilizing the available sources sustainably.

QDs embedded copolymer nanospheres prepared with a simple self-stable precipitation polymerization method for Listeria monocytogenes detection

In this paper, a simple self-stable precipitation polymerization method was used to prepare fluorescent quantum dots (QDs) embedded styrene-maleic anhydride copolymer nanospheres. Compared with conventional polymerization process, we only need to dissolve hydrophobic QDs, styrene, maleic anhydride, and initiator in cyclohexane/isoamyl acetate mixed solvent and implemented the polymerization process without requiring any stabilizers, surfactants, and continuous stirring. The most important influence parameter on the internal structure of QDs embedded nanospheres, such as cyclohexane/isoamyl acetate volume ratio was systematically investigated. After hydrolysis, the obtained nanospheres were functionalized with carboxyl groups, which could be conjugated with antibodies to capture target proteins in a sandwich assay format. Using Listeria monocytogenes as a model biomarker in a lateral flow immunoassay (LFIA) detection system, we achieved a detection limit of as low as 104 CFU/mL, which is at least one log lower than conventional LFIA.

SMA-Assisted Exfoliation of Graphite by Microfluidization for Efficient and Large-Scale Production of High-Quality Graphene.

In this paper, the sodium salt of styrene-maleic anhydride copolymer (SMA) was used as a stabilizer in the process of graphite exfoliation to few-layer graphene using the technique of microfluidization in water. This method is simple, scalable, and cost-effective, and it produces graphene at concentrations as high as 0.522 mg mL−1. The generated high-quality graphene consists of few-layer sheets with a uniform size of less than 1 μm. The obtained graphene was uniformly dispersed and tightly integrated into a polyamide 66 (PA66) matrix to create high-performance multifunctional polymer nanocomposites. The tensile strength and thermal conductivity of 0.3 and 0.5 wt% EG/PA66 composites were found to be ~32.6% and ~28.8% greater than the corresponding values calculated for pure PA66, respectively. This confirms that the new protocol of liquid phase exfoliation of graphite has excellent potential for use in the industrial-scale production of high-quality graphene for numerous applications.

Determination of Th(IV) in Natural Waters after Preconcentration with a Chelating Sorbent

Chelating sorbents containing norsulfazole and sulfadimezine fragments were prepared by modification of maleic anhydride-styrene copolymer with amines. The conditions of the Th(IV) sorption onto these sorbents were studied. The maximal sorption was observed at pH 5. The effect of various acids on the Th(IV) desorption from the sorbents was examined. The developed procedure was applied to the Th(IV) determination in water via preconcentration.