Styrene-maleic Anhydride Copolymer Research Articles

Microencapsulation mechanism and size control of fragrance microcapsules with melamine resin shell

Abstract Fragrance microcapsules, with a methanol-modified melamine-formaldehyde (MMF) resin shell, were fabricated with an in situ polymerization method in the presence of styrene-maleic anhydride copolymer (SMA). The FT-IR results showed that the essence oil was encapsulated by MMF resin, and TG-DTG tests indicated that its thermal stability was improved significantly by the microencapsulation. The fabrication process was observed by reflection and transmission optical microscope, and the encapsulation mechanism was studied according to the observation results. It was found that the adsorption of MMF resin to SMA and the polycondensation reaction kinetics played key roles in the microencapsulation process. Additionally, the process of microencapsulation contains two re-formations, which were caused by the pH effect in the hydrolysis of SMA and the redispersion of droplets in curing process. According to the proposed encapsulation mechanism, a series of microcapsules with different size and distribution were prepared by the adjustment of reaction parameters.

Improved rheological and electrical properties of graphene/polystyrene nanocomposites modified with styrene maleic anhydride copolymer

Styrene–maleic anhydride copolymer (SMA) was used as a compatibilizer to improve the interfacial interaction between graphene sheets and polystyrene matrix. SMA mediated graphene sheets are closely encapsulated by a polymer layer and uniformly dispersed compared to the graphene sheets without SMA. The presence of SMA not only improves the melt modulus and its frequency-independence, but also results in an earlier transition from liquid-like to solid-like, indicating the formation of a percolated conducting network at a low content of graphene with the assistance of SMA. Accordingly, the different frequency dependences of electrical conductivity also lead to a much lower threshold of 0.17 vol.% for SMA modified nanocomposites compared to 0.52 vol.% for the unmodified counterparts, further confirming the earlier formation of a graphene network in the matrix. The improved rheological and electrical properties of the polystyrene nanocomposites are attributed to the homogeneous dispersion of the graphene sheets and the enhanced interfacial interaction between the graphene sheets and the polystyrene matrix.

The simultaneous addition of styrene maleic anhydride copolymer and multiwall carbon nanotubes during melt-mixing on the morphology of binary blends of polyamide6 and acrylonitrile butadiene styrene copolymer

The effect of simultaneous addition of multiwall carbon nanotubes (MWNTs) and a reactive compatibilizer (styrene maleic anhydride copolymer, SMA) during melt-mixing on the phase morphology of 80/20 (wt/wt) PA6/ABS blend has been investigated. Morphological analysis through scanning and transmission electron microscopic analysis revealed finer morphology of the blends in presence of SMA + MWNTs. Fourier transform infrared spectroscopic analysis indicated the formation of imide bonds during melt-mixing. Non-isothermal crystallization studies exhibited the presence of a majority faction of MWNTs in the PA6 phase of 80/20 (wt/wt) PA6/ABS blend in presence of SMA + MWNTs. Rheological analysis, dynamic mechanical thermal analysis, and thermogravimetric analysis have demonstrated the compatibilization action of simultaneous addition of a reactive compatibilizer (SMA copolymer) and MWNTs in PA6/ABS blends. An attempt has been made to investigate the role of simultaneous addition of SMA copolymer and MWNTs on the morphology of 80/20 (wt/wt) PA6/ABS blend through various characterization techniques. POLYM. ENG. SCI., 55:457–465, 2015. © 2014 Society of Plastics Engineers

Thermo-analytical study on transitions in styrene–maleic anhydride copolymers with low- and high-molecular weights

Abstract The thermal behaviour near the glass transition temperature Tg was studied for poly(styrene-co-maleic anhydride) or (SMA) copolymers with a broad range of molecular weight (Mw = 5500–180,000 g/mol) and amount of maleic anhydride (22–50 mol%). The influences of molecular structure for low- and high-molecular weight copolymers were detailed by using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and temperature modulated differential scanning calorimetry (TMDSC). Data from TGA provide evidence for variations in thermal stability, mainly over the first degradation step up to 350 °C. Most interesting data results from TMDSC for high-molecular weight SMA, where the transition in reversible heat flow and Δcp remains almost constant, while the transition in non-reversible heat flow and Δcp gradually increases with amount MA. Comparing low- and high-molecular weight SMA, a linear model for Tg cannot be applied for the global amount of maleic anhydride, while it can be successfully implemented if a more detailed molecular structure with two constituents is considered. As such, further evidence is provided for the intrinsic heterogeneous molecular structure of high-molecular weight SMA with “styrene-rich” and “maleic-anhydride-rich” polymer segments.

Cross-linked starch nanoparticles stabilized Pickering emulsion polymerization of styrene in w/o/w system

Here, we present a method to synthesize expandable spherical polystyrene beads containing well-dispersed water microdroplets. The beads, 2–3 mm in diameter, were prepared through surfactant-free Pickering emulsion polymerization in water-in-oil-in-water (w/o/w) system using cross-linked starch nanoparticles (CSTN) as emulsifier. The CSTNs were in situ surface-modified by styrene maleic anhydride copolymer as confirmed by infrared spectroscopy and contact angle analysis. The entrapped water microdroplets with the average size of 3–4 μm were shown to be surrounded by a dense layer of the CSTN. The number droplet density as well as water encapsulation efficiency in the polystyrene beads increased with the CSTN concentration. Furthermore, regardless of CSTN content, all samples exhibited high encapsulation stability of over 68 % after 3 months. These characteristics along with good expansion behavior suggest the synthesized beads as expandable polystyrene containing water as a green blowing agent.

Preparation and Properties of Microencapsulated Phase Change Materials Containing Two-Phase Core Materials

Microencapsulated phase change materials (MicroPCMs) containing two-phase core materials, in which polypyrrole (PPy) particles were homodispersed in n-octadecane (n-Oct), were synthesized by two-step polymerization technique using poly(methyl methacrylate-co-allyl methacrylate) as shell. The surface morphologies, phase change properties, and thermal stabilities of the microcapsules were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), respectively. The results show the two-phase core materials are well encapsulated in the presence of the emulsifier sodium salt of styrene–maleic anhydride copolymer. The average diameter of the microcapsules is about 35 μm. The crystallization temperature of MicroPCMs is higher than that of MicroPCMs without PPy. At the same time, the enthalpy of the heterogeneous nucleation significantly increased with increasing of the PPy concentration. Microcapsules with 4–14 wt % PPy in the core material w...

폴리카보네이트/신디오탁틱 폴리스티렌 블렌드의 상용성 및 Encapsulation 상용화

The miscibility of the blends of polycarbonate (PC) and syndiotactic polystyrene (s-PS) was investigated by using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The blends exhibit two different glass transition temperatures (<TEX>$T_g$</TEX>) close to those of the pure components, indicating immiscibility at the melt mixing temperature of <TEX>$280^{\circ}C$</TEX>. Morphological studies of the blends shows large dispersed particles and significant cavities between the matrix and the dispersed phase, especially for the PC matrix blends. To reduce such detrimental effects, poly(methyl methacrylate) (PMMA) or styrene-maleic anhydride copolymer (SMA) was added as a compatibilizer to the PC/s-PS blends. Both polymers contribute to enhancing the interfacial adhesion between PC and s-PS and reduce the particle size of the dispersed phase. Especially when PMMA was added, morphological studies showed that PMMA encapsulates the dispersed s-PS phase in the PC matrix. The elastic modulus of the PC/s-PS blend increased on adding PMMA or SMA, mainly because of enhanced interfacial adhesion. The pencil hardness of PC increased at least three times from that of neat PC as a result of compatibilization and surface enrichment of the s-PS phase, whose surface tension is lower than that of PC.

Polyscope extends XIRAN® portfolio with low molecular weight styrene maleic anhydride co-polymers

Polyscope extends XIRAN® portfolio with low molecular weight styrene maleic anhydride co-polymers

Study on Synthesis and Characterization of Styrene-Maleic Anhydride Random Copolymer by Xylene

Radical copolymerization of styrene (St) and maleic anhydride (MA) were typically alternating copolymerization, which generated copolymer styrene-maleic anhydride (SMA). The copolymer was synthesized by solution polymerization method,with benzoyl peroxide (BPO) as initiator and xylene as solvent, and using the yield of copolymer as evaluation criteria, the reaction conditions were researched. The maleic anhydride of molar fraction was 45% in the copolymer measured by chemical titration, combined with the theoretical that the synthesis of styrene-maleic anhydride copolymer was confirmed to be the alternating copolymer. The structure and character of the copolymer was also confirmed by IR. The glass-transition temperature of the alternating copolymer was tested by DSC.

Polyscope extends XIRAN® portfolio with low molecular weight styrene maleic anhydride co-polymers

Polyscope extends XIRAN® portfolio with low molecular weight styrene maleic anhydride co-polymers

Composite macrocapsule of phase change materials/expanded graphite for thermal energy storage

Three kinds of macro-encapsulated phase change materials (MacroPCMs) were fabricated, i.e., MacroPCMs with a single core–shell structure, MacroPCMs containing microencapsulated phase change materials (MicroPCMs), and composite macrocapsules of MicroPCMs/expanded graphite prepared by suspension-like polymerization followed by a piercing–solidifying incuber process. The morphology, microstructure, phase change property, as well as seal tightness were systematically characterized by field emission scanning electron microscope (FESEM), differential scanning calorimetry (DSC), and energy dispersive X-ray spectrometer (EDS). The core–shell structured macrocapsules exhibit a homogeneous thickness shell. The interface combination between MicroPCMs and polymer substrate was studied through the cross section micrograph of MacroPCMs containing MicroPCMs. The morphology and seal tightness of MacroPCMs fabricated with expanded graphite absorbing both PCMs and shell-forming monomers, enhanced significantly compared with that of PCMs alone. In addition, the effects of polymer substrate proportion between styrene-maleic anhydride copolymer and sodium alginate on the microstructure and performance of MacroPCMs were discussed as well.

RISUG: A new perspective in non–hormonal male contraception

Abstract Currently there are several hormonal and non-hormonal methods of contraception available but due to long term side effects of hormonal contraceptives, a great research is undergoing to develop an effective and noninvasive non-hormonal male contraceptive. One of the product of this research is RISUG (an acronym for the Reversible Inhibition of Sperm Under Guidance). RISUG is a co-polymer of Styrene Maleic Anhydride (SMA) dissolved in Dimethyl Sulfoxide (DMSO) to form a gel. This gel is then introduced in the lumen of male vas deferens which results in the partial blockage of vas deferens. It causes the disruption of the membrane of spermatozoa and release of enzymes that are essential for the fertilization of ova. Thus the ejaculation after RISUG contains infertile spermatozoa.

Role of compatibilizer and processing method on the mechanical, thermal and barrier properties of polystyrene/organoclay nanocomposites

This study describes the role of compatibilizer i.e. styrene-maleic anhydride copolymer, its content and compounding method on the properties of polystyrene/clay nanocomposites. The nanocomposites were fabricated using three different methods: (i) simultaneous mixing of all the components i.e. polystyrene, required amounts of styrene-maleic anhydride and nanoclay using twin-screw extruder; (ii) stepwise mixing method i.e. in which blending of polystyrene and organoclay was first done using single-screw extruder and the mixed compound was then blended with varying amounts of styrene-maleic anhydride copolymer using twin-screw extruder and (iii) the effective combination of in situ polymerization of styrene-maleic anhydride copolymer in presence of varying amounts of nanoclay by free radical polymerization followed by melt mixing with polystyrene using twin-screw extruder. The effect of processing method on the micrsostructure of nanocomposites was investigated using X-ray diffraction and transmission electron microscopy. The mechanical properties of nanocomposites such as tensile, flexural and Izod impact strength were measured and discussed in relation to their microstructure. All the fabrication methods yielded nanocomposites with different microstructure ranging from intercalated to exfoliated structure of nanoclay. As expected the stepwise mixing method yielded more intercalated and exfoliated structure as compared to the simultaneous mixing method resulting in improvement in the properties of nanocomposites. On the other hand, combination of in situ polymerization with melt mixing method produced better exfoliation as compared to other two methods. Thermal stability and mechanical strength of polystyrene showed a significant improvement upon incorporation of nanoclay.

Determination of uranium(VI) in natural waters after preconcentration on adsorbent containing m-aminophenol fragments

Sorption and complexing properties of a modified adsorbent based on a maleic anhydride-styrene copolymer towards uranium(VI) are studied and the main quantitative characteristics of the metal ion sorption are determined. An adsorbent containing m-aminophenol fragments is proposed for the selective sorption of uranium(VI) from solutions. The optimal sorption conditions have been found. The recovery of uranium(VI) under the optimal conditions exceeds 95%. A procedure of the sorption photometric determination of uranium(VI) in sea water is developed.

Styrene maleic acid anhydride copolymer (SMA) for the encapsulation of sparingly water-soluble drugs in nanoparticles

Styrene maleic acid copolymer (SMA) is widely used in various industrial applications, such as adhesives and coatings, because of its good durability and low cost. In this study, we investigated the biological safety and functions of nanoparticle formulations with varying molecular weights of SMA. The toxicity of SMA, measured by hemolytic activity and body weight loss, was examined in mice. Amphotericin B (AmB) and all-trans retinoic acid (ATRA) are limited in clinical use because of their poor water solubility. We prepared AmB- and ATRA-loaded SMA nanoparticles for the first time; these are self-assembled nanoparticles with a high drug-loading capacity. The formation of monodispersed nanoparticles by self-assembly of SMA and their complex formations with drugs were studied by size-exclusion chromatography (HPSEC) and dynamic light scattering. After intravenous injection of the drug-loaded SMA nanoparticles, prolonged blood circulation of AmB and ATRA was observed.

Modification of the grafting character to prepare PA6/ABS-g-MA blends with higher toughness and stiffness

Tert-dodecyl mercaptan (TDDM) was used to modify the grafting character of maleic anhydride–functionalized acrylonitrile–butadiene–styrene core–shell particles (ABS-g-MA). With the increase of TDDM content, the grafting degree and grafting efficiency of ABS-g-MA particles decrease, which induce the decrease of grafted acrylonitrile–styrene–maleic anhydride copolymer (g-SAM) and the increase of free acrylonitrile–styrene–maleic anhydride copolymer (f-SAM). The change of the g-SAM and f-SAM content modifies the chemical reactions degree at the interface and in the matrix. The interface reaction can decrease the interfacial tension and prohibit the agglomeration of ABS-g-MA particles, which have been testified by Molau test and SEM observation. The interface reaction is beneficial to the toughness improvement and the reaction in the matrix leads to higher stiffness. In the present paper, when TDDM content is 0.28 %, PA6/ABS-g-MA blend shows superior toughness and higher stiffness.

Synthesis and Properties Measurement of Pour Point Depressant

The amidation grafted copolymers derived from styrene-maleic anhydride copolymer were prepared and characterized by FTIR. Their intrinsic viscosity and crystal morphology were measured. The prepared polymers were investigated as pour point depressants (PPD) and flow improvers for waxy crude oil, and it was found that the depression effect of PPD modified by mixture amines was more effective than single amine, and the maximum depression was obtained by the sample that modified by mixture amines from 13 °C to 4 °C (ΔPP = 9 °C, at 3 000 ppm). The effect of the PPD modified by mixture amines on the flow properties of waxy crude oil was investigated. The result show that the viscosity decreased from 1 223 mPa.s to 81.3 mPa.s at 13 °C and 3 000 ppm. In addition, the crystal morphology have also been improved for the same sample and conditions.

Powder X-ray diffraction and thermal decomposition correlation studies of nano-crystalline styrene-maleic anhydride graft copolymer-ZnO composites

AbstractNano-crystalline (nc) polymer-ZnO composite material has been successfully synthesized by treating styrene-maleic anhydride (SMA) and its graft copolymers with acrylic acid, (AAc), and acrylamide, (AAm), synthesized by chemical method with different wt% ratios of nZnO (40 nm), prepared indigenously in our laboratory, to yield polymer-ZnO nano-composite material. Characterization of SMA, grafted SMA, nc-SMA-ZnO, nc-grafted SMA-ZnO composites was carried out by X-ray diffraction and thermo-gravimetric analysis. Both the studies show an interesting correlation between X-ray and thermal data. XRD pattern of SMA copolymer shows it to be amorphous, while SMA-g-poly(AAc) and SMA-gpoly( AAm) graft copolymers show crystalline orthorhombic structure having (102) orientation with particle size of nano dimensions (44 and 40 nm respectively). Addition of nZnO to nc-SMA-g-poly(AAc) and nc-SMA-g-poly(AAm) shows appreciation in the crystalline behavior with increased intensity of the peaks in the XRD patterns. Thermo-gravimetric analysis (TGA) of SMA shows single stage decomposition with regular loss of weight while nc-SMA-g-poly(AAc) and nc-SMAg- poly(AAm) graft copolymers respectively show an abrupt weight loss up to 25% and 45% at 121.370C and thereafter proceeds with regular decomposition. However, the corresponding composite of SMA with nZnO (10 wt%) shows an abrupt weight loss of 50% similar to grafted SMA while the ZnO embedded composites of AAc and AAm grafted SMA lose 95% of the weight abruptly at the same temperature i.e.121.37 °C. The increased abrupt loss in nZnO- SMA and nZnO-nc-SMA grafted composite is correlated to the increased crystallinity upon addition of nZnO particles to the polymer system. Because of the spontaneous thermal decomposition and release of large amount of heat energy, the newly synthesized nano-composite polymer material can find use as high energy material

Preparation of Comb‐Like Amphiphilic Styrene Maleic Anhydride Copolymer Derivatives and Their Modification to Surface of Chrome‐Tanned Collagen Fiber

AbstractA series of comb‐like amphiphilic surfactants of sodium salts of fatty alcohol polyoxyvinethene monoester, i.e., SMA‐g‐O‐3, SMA‐g‐O‐6, SMA‐g‐O‐10, SMA‐g‐O‐15 and SMA‐g‐O‐20, were prepared through the esterification modification to styrene‐maleic anhydride copolymer (SMA) using fatty alcohol polyoxyethylene ether in dimethylformamide(DMF). The products of esterification modification were characterized by FTIR and GPC analysis, and the esterification reaction rate was calculated by measuring the acid values of SMA and its esterification product. Then, sodium salts of those esterification substances were applied to the leather retaining and fatliquoring process to study their effects on hydrophobicity of the treated leather fiber, such as static Water Contact Angle (WCA) on the leather surface and water absorption of the treated leather. Results showed that all the esterification rates were more than 90 %; moreover, both the WCA and water absorption of the processed chrome‐tanned collagen fibers were related to the number of oxyethyl groups in the fatty alcohol polyoxyethylene ether. WCA decreases and water absorption increases instead with augmentation of the oxyethyl group number.

Preparation, water absorbent and mechanical properties of water swellable rubber

Water swellable rubber was prepared by blending styrene butadiene rubber as a matrix, cross-linked poly sodium polyacrylate (PAANa) as a high absorbent water resin, copolymer styrene maleic anhydride as a compatibiliser and polyethylene glycol as an absorbent accelerant. The preparation process was described. The effects of various preparation conditions, such as amount of sulphur, ratio of silicon dioxide to nanocalcium carbonate, amount of PAANa and amount of compatibiliser, on its water absorbency and mechanical properties were investigated by orthogonal tests. The optimal reaction conditions were 2 portion (phr) sulphur, 28∶12 silicon dioxide/nanocalcium carbonate, 60 phr PAANa and 5 phr compatibiliser. Furthermore, the vulcanisation property of the rubber was measured.