Styrene Ethylene Butylene Research Articles

A novel flexible composite phase change material with enhanced toughness and shape stability for battery thermal management

The application of flexible composite phase change materials (FCPCM) in the thermal management of batteries has been widely studied. However, flexible materials can sometimes tear, so improved toughness and morphological stability are required. In this work, a new stable flexible composite phase change material, with good toughness is prepared, which is composed of paraffin, Styrene Ethylene Butylene Styrene (SEBS), Olefin Block Copolymer (OBC) and Expanded Graphite (EG). The thermal properties, toughness, morphological stability, and other properties of the fabricated FCPCMs are tested, and battery thermal management experiments are conducted to explore its thermal management potential. The results show that the elongation at break are about 150 % and 240 % of the FCPCM at the same temperature with OBC as the supporting material at 25 °C and 40 °C, respectively, which shows good toughness. It can still maintain a stable form under the high-temperature condition of 110 °C. The physical and chemical compatibility of each component of the FCPCM is good. The 24 h leakage rate is maintained below 1 %, which is only 56 % of the leakage rate of the FCPCM with OBC as the support material. In general, 8 wt% SEBS and 8 wt% OBC are the best ratio. In addition, the battery thermal management experiment shows that the FCPCM can control the battery temperature at 49.3 °C at a 2C rate, which is 10 °C lower than the condition without FCPCM. The FCPCM reduces the temperature fluctuation of the battery by at least 1 °C, whether it is charged at 1C or 2C. This shows good thermal management potential.

Advancements in numerical modelling of synthetic gel for ballistic impact assessment

A synthetic gel based on SEBS (styrene-ethylene-butylene-styrene), commonly used as a human soft tissue simulant, was characterised over a wide range of strain rates. Material parameters were derived from quasi-static and dynamic tests using DMA. These parameters were then integrated into a visco-hyperelastic material law based on an Ogden model. Ballistic impact simulations showed good agreement with experimental analysis.

Thermoplastic elastomer melt-blown fiber mats for oil spill remediation: Fabrication, oil uptake, and gel formation studies

Melt-blown fibers, featuring porous structures with designed wetting characteristics can provide superior oil/water separation performance. The core objective of this work was to design a material that provides excellent oil/water selectivity for oil spill remediation. For this, the selective oil gelation properties of styrene-ethylene-butylene-styrene (SEBS) and the enhanced surface area provided by melt-blown mats was leveraged to achieve exceptional oil/water selectivity. Nonwoven mats based on SEBS were fabricated with a twin-screw extruder equipped with a custom-engineered melt-blowing die. To address the inherent low melt flow index (MFI) of SEBS, which presents challenges in the melt-blowing process due to decreased stretchability, high MFI polypropylene (PP) was incorporated as a blending additive. Next, the impact of blending polypropylene with SEBS on melt-blowing processability and fiber quality was studied. The inclusion of 10 wt% PP in SEBS considerably enhanced fiber melt-blowing processability, resulting in a more extensive and evenly spread fiber stream. Further analysis of this fiber composition in terms of oil and water interaction revealed superior oil uptake capacity. Moreover, the increased surface area of SEBS-based fibers enhanced their interaction with oil, resulting in the effective formation of a semi-solid gel. Notably, the generated gel established a barrier that successfully limited further oil dispersion even when the material reached its saturation point. This demonstrated a markedly superior oil immobilizing performance in comparison to polypropylene melt-blown fibers.

Flexible thermoelectric energy harvesting system based on polymer composites

Flexible and easy processing lightweight thermoelectric materials for energy harvesting applications have shown an increasing interest. Thermoplastic polyvinylidene fluoride (PVDF) and elastomer styrene-ethylene/butylene-styrene (SEBS) polymers reinforced with thermoelectric ceramics, including bismuth sulfide (Bi2S3), bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3), and electrically conductive carbon nanotubes (CNT) have been developed, tailoring their thermal and electrical properties for thermoelectric device applications. The Seebeck coefficient of the composites increases with thermoelectric ceramic filler content for semicrystalline PVDF composites, slightly decreasing for amorphous SEBS composite. Thermoelectric power factor and figure-of-merit in the polymer composites increases up to 9 orders of magnitude with respect to the pristine polymer, up to a maximum value of 10−3 µW/(m·K2) and 10−6, respectively, for the PVDF/CNT/Bi2Te3 composite. A device composed by 2 printable p-n thermocouples based on PVDF/50Bi2S3 and PVDF/50Bi2Te3 can generate power in the order of the nW and charge a capacitor with 5 V. Theoretical modeling allows to evaluate different thermoelectric configurations, the effect of the number of thermocouples and the influence of the temperature gradient on device performance.

Environmentally Friendlier Printable Conductive and Piezoresistive Sensing Materials Compatible with Conformable Electronics.

Flexible and conformable conductive composites have been developed using different polymers, including water-based polyvinylpyrrolidone (PVP), chemical-resistant polyvinylidene fluoride (PVDF), and elastomeric styrene-ethylene-butylene-styrene (SEBS) reinforced with nitrogen-doped reduced graphene oxide with suitable viscosity in composites for printable solutions with functional properties. Manufactured by screen-printing using low-toxicity solvents, leading to more environmentally friendly conductive materials, the materials present an enormous step toward functional devices. The materials were enhanced in terms of filler/binder ratio, achieving screen-printed films with a sheet resistance lower than Rsq < 100 Ω/sq. The materials are biocompatible and support bending deformations up to 10 mm with piezoresistive performance for the different polymers up to 100 bending cycles. The piezoresistive performance of the SEBS binder is greater than double that the other composites, with a gauge factor near 4. Thermoforming was applied to all materials, with the PVP-based ones showing the lowest electrical resistance after the bending process. These conductive materials open a path for developing sustainable and functional devices for printable and conformable electronics.

Interfacial shear strength of surface functionalized and functionalized CNT coated carbon fiber: A single fiber fragmentation study

The compatibility among nonpolar thermoplastics like polypropylene (PP) and carbon fibers (CF) having traditional sizing or coating is challenging. In this study, facile and effective surface functionalization of CF and its subsequent coating with functionalized carbon nanotubes (CNTs) were carried out to obtain improved interfacial shear strength (IFSS) which was validated by the single fiber fragmentation test (SFFT). Functional groups, -COOH, -OH, and -NH2, were separately grafted on the CF surface using different chemical routes. Additionally, ultrasonic assisted electrophoretic deposition (EPD) technique was used to coat -COOH, -OH, and -NH2 functionalized CNTs on the sized and surface functionalized CFs. Attenuated total reflection-infrared spectroscopy (ATR-IR), X-ray photoelectron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM) images confirmed the successful surface functionalization and coating on CF. Neat PP and a blend of PP and maleic anhydride-grafted-styrene ethylene butylene styrene (MA-g-SEBS) were used as two different base polymer matrixes in preparing a total of 26 different SFFT samples. Silane functionalized CF coated with amine functionalized CNTs using ultrasonic assisted EPD process showed IFSS of ∼29 MPa which was an impressive ∼758% higher than pristine CF and highest among all the surface modified CFs. Interestingly, this translated into useful increase of ∼13% in single fiber tensile strength of functionalized and treated CF over and above that of as received CF.

Fabrication of Triblock Elastomer Foams for Oil Absorption Applications: Effects of Crosslinking, Composition, and Rheology Factors

Oil spill accidents and oil-contaminated wastewater release from industries cause severe environmental pollution, resource waste, and economic loss. Thus, there is a dire need for an efficient oil/water separation approach to mitigate the challenge. Among the various oil/water separation technologies, employing oil-absorbing materials is one of the most effective strategies. In this work, a highly effective elastomer foam based on styrene–ethylene–butylene–styrene (SEBS) and ethylene propylene diene monomer (EPDM) blend was developed. Dicumyl peroxide was employed as a radical initiator for the crosslinking of the elastomer blend. The crosslinking of the blend significantly increased the melt strength of the SEBS/EPDM blend and therefore allowed them to expand extensively (up to 1200 vol %) with substantial volume increase (expansion ratio 12.8–13.1) and created pores with well-defined structures. As a result, the material exhibited outstanding oil absorption (up to 1030 wt %) due to an enlarged surface area and blend constituents. The incorporation of EPDM and radical-mediated crosslinking prevented the dissolution of SEBS in the oil and maintained the structural integrity of the foam in the oil, paving the way for recyclability. Also, the inherent hydrophobicity of employed polymers led to poor interaction with water and, thus, outstanding oil/water separation ability of the developed elastomer foams. Additionally, the foaming of triblock polymers, including SEBS, remained largely unexplored. This study has elucidated the impact of crosslinking and rheological factors on the successful foaming of SEBS.

Additive manufacturing of zirconia ceramic by fused filament fabrication

Fused filament fabrication (FFF) technology will facilitate the standardization of consumables and printing equipment for the additive manufacturing of engineered ceramics. In this study, a thermoplastic elastic binder based on styrene ethylene butylene styrene (SEBS) was optimized to realize the preparation of flexible filaments with solid loading of 43 vol%. The rheology, stress-strain behavior, and printing performance of the filament were systematically evaluated, and the feasibility of the fabrication of complex-shaped parts was verified. A microstructure model of the filament was innovatively established. The printed parts are suitable for solvent debinding at 40 °C, followed by thermal debinding and sintering to obtain dense zirconia ceramic materials. Microstructural analysis revealed two types of typical defects, interlayer bonding defects with a scale of about 1 μm and triangular voids at path intersections with a scale of about 10 μm. Zirconia ceramics with a relative density of 99.1% and a flexural strength of 492.8 ± 40 MPa was obtained by the FFF method.

Thermoplastic Toughening of a Semiaromatic Polyamide with an Amino-telechelic Polyethylene.

Semiaromatic polyamides are used for metal replacement in advanced engineering applications to reduce weight and improve efficiency, but their range of application is limited by their inherent lack of ductility and toughness. Here, we combined semiaromatic polyamide poly(hexamethylene terephthalamide-co-isophthalamide) (PA6TI) with up to 30 wt % amine-terminated polyethylene (PE(NH2)2) by high-temperature melt compounding, which was suggested to lead to the formation of PA-PE block copolymers at the interface between the PE(NH2)2 and the PA6TI. This resulted in PA6TI/PE(NH2)2 blends with smaller, more uniform particle sizes than in PA6TI blended with nonfunctional PE or the commercial impact modifier, maleic anhydride-functionalized styrene-ethylene-butylene-styrene (SEBS) under the same conditions. The PA6TI/PE(NH2)2 blends and the corresponding glass fiber-reinforced composites consequently showed significantly greater increases in room-temperature tensile ductility and fracture energy with respect to unmodified PA6TI, as well as maintained mechanical stability at high temperatures, and only modest decreases in stiffness and strength, even at high PE(NH2)2 contents. These improvements were attributed to the crystallinity of the PE(NH2)2 particles and to improved morphological stabilization and matrix-particle adhesion, consistent with the presence of PA-PE block copolymer at the matrix-particle interfaces.

Printable piezoresistive polymer composites for self-sensing medical catheter device applications

There is a constant demand for new and/or improved health treatments that require flexible sensor devices. This is particularly relevant in relation to neurogenic bladder dysfunction.In this context, polymer composites have been developed based on three different matrices, carboxymethyl cellulose (CMC), styrene-ethylene/butylene-styrene (SEBS) and polyvinyl alcohol (PVA), with different concentrations of multiwalled carbon-nanotubes (CNT) filler contents for catheter medical device application.The mechanical properties of the nanocomposites are critically dependent on the polymeric matrix and also depend on CNT content with maximum strain is about 4%, 100% and 700% for CMC, PVA and SEBS materials, respectively. Electrical conductivity increases near 10 orders of magnitude up to 0.11 S/m for PVA with 5 wt percentage (wt.%) of CNT, one magnitude order than the most filled PVA and CMC composites. The percolation threshold (fc) of the composites are fc = 3 wt% for CMC, fc = 2 wt% for SEBS, and fc = 1 wt% for PVA as polymer matrices. Furthermore, the functional performance of the composites is characterized by the piezoresistive response, with a gauge factor (GF) ranging between 1 and 6 for the different composites. Finally, a self-sending catheter device was developed as a proof-of-concept, based on a PVA composite with a GF∼1.5. demonstrating proper adhesion and excellent sensing behavior at bending up to 7 mm.Thus, it is demonstrated that screen-printable piezoresistive sustainable composites can be developed for medical application with excellent electrical and mechanical properties.

Microstructural, Mechanical, and Tribological Performances of Composites Prepared via Melt Compounding of Polyamide 6, Basalt Fibers, and Styrene-Ethylene-Butylene-Styrene Copolymer.

Basalt fibers (BFs) are environmentally friendly materials characterized by high strength and good wear resistance, and thus are popular candidates for reinforcing polymers. Herein, polyamide 6 (PA 6), BFs, and the styrene-ethylene-butylene-styrene (SEBS) copolymer were melt compounded sequentially to prepare fiber-reinforced PA 6-based composites. The results showed improved mechanical and tribological performances via the incorporation of BFs and SEBS into PA 6. Compared to neat PA 6, an average 83% increase in notched impact strength was achieved for the PA 6/SEBS/BF composites, which is mainly due to the good miscibility between SEBS and PA 6. The tensile strength of the composites, however, was only increased moderately, since the weak interfacial adhesion was not sufficiently efficient to transfer the load from the PA 6 matrix to the BFs. Interestingly, the wear rates of both the PA 6/SEBS blend and the PA 6/SEBS/BF composites were obviously lower than those of the neat PA 6. The PA 6/SEBS/BF composite with 10 wt.% of the BFs exhibited the lowest wear rate of 2.7 × 10-5 mm3/N·m, which was decreased by 95% compared to that of the neat PA 6. The facilitation of forming tribo-film with SEBS and the naturally good wear resistance of the BFs were responsible for the largely decreased wear rate. Moreover, the incorporation of SEBS and BFs into the PA 6 matrix transformed the wear mechanism from adhesive wear to abrasive wear.

A molecular dynamics assisted insight on the enhancement of interfacial adhesion of carbon fiber with polypropylene matrix via a combination of surface functionalization and defect laden carbon nanotube coating

The low compatibility of traditional carbon fibers with thermoplastics results in an inferior interfacial interaction. Therefore, it prohibits full exploitation of low-cost thermoplastics like polypropylene in developing high-strength carbon fiber reinforced composites. In the present study, atomistic and mesoscopic molecular dynamics simulations are carried out to postulate enhancement in interfacial shear strength among amine terminated carbon fiber and polypropylene. Pristine and amine functionalized carbon nanotubes are coated to the amine terminated carbon fiber separately. The influence of Stone-Wales and Di-vacancy defects of carbon nanotubes, with their varying defect concentration, is investigated. Besides, maleic anhydride-grafted-styrene ethylene butylene styrene is used as a compatibilizer. Interaction energy among maleic anhydride-grafted-styrene ethylene butylene styrene and amine terminated carbon nanotubes increases with amine weight percentage over carbon nanotube. The highest optimal interaction energy is shown by carbon nanotube functionalized with 6 wt percent amine groups and having 3 Stone-Wales defects, which is ∼41% higher than that with pristine carbon nanotubes. The pull-out coarse-grain simulations of the amine terminated carbon fiber coated with such optimal carbon nanotubes displayed the highest interfacial shear strength of 31.11 MPa, and it was ∼106% higher than the composite reinforced with neat carbon fiber.

Self-Powered Integrated Sensing System with In-Plane Micro-Supercapacitors for Wearable Electronics.

Self-powered integrated sensor with high-sensitivity physiological signals detection is indispensable for next-generation wearable electronic devices. Herein, a Ti3 C2 Tx /CNTs-based self-powered resistive sensor with solar cells and in-plane micro-supercapacitors (MSCs) is successfully realized on a flexible styrene-ethylene/butylene-styrene (SEBS) electrospinning film. The prepared Ti3 C2 Tx /CNTs@SEBS/CNTs nanofiber membranes exhibit high electrical conductivity and mechanical flexibility. The laser-assisted fabricated Ti3 C2 Tx /CNTs based-MSCs demonstrate a high areal energy density of 52.89 and 9.56µWhcm-2 with a corresponding areal power density of 0.2 and 4mWcm-2 . Additionally, the MSCs exhibit remarkable capacity retention of 90.62% after 10 000 cycles. Furthermore, the Ti3 C2 Tx /CNTs based-sensor exhibits real-time detection capability for human facial micro-expressions and pulse single under physiological conditions. The repeated bending/release tests indicate the long-time cycle stability of the Ti3 C2 Tx /CNTs based-sensor. Owing to the excellent sensing performance, the sensing arraywasalso fabricated. It is believed that this work develops a route for designing a self-powered sensor system with flexible production, high performance, and human-friendly characteristics for wearable electronics.

Activatable Conformal Electrode Arrays for Highly Stable and Breathable 12‐Lead Clinical Electrocardiographic Monitoring

AbstractIn clinical practices, ambulatory electrocardiography (ECG) signals are a significant index in early diagnosis of heart diseases. Commercial 12‐lead Holter monitors are widely used to evaluate the heartbeat over time. However, poor sweat‐proof adhesion, low water vapor transmittance, and wired connectivity of Holter monitors limit their popularization in wearable electronics. Herein, a facile, low‐cost, and scalable stretchable supramolecular material with activatable high adhesion is reported, which can be used to fabricate breathable on‐skin electrode arrays for stable 12‐lead ECG monitoring applications. In the proposed strategy, a supramolecular polymer network with various dynamic chemical bonds is obtained, resulting in the material exhibiting good stretchability. The introduction of tannic acid (TA) ensure high intrinsic adhesion at wet/dry skin surfaces. Moreover, the combination of poly (lipoic acid) and TA can realize alcohol‐activated high adhesion. Subsequently, electrode arrays are assembled using adhesive layers comprising supramolecular materials and a stretchable conductive Styrene Ethylene Butylene Styrene (SEBS)/Au layer. In addition, the micromesh structures obtained by laser scribing endowed the electrodes with good water/air permeability. Finally, the breathable on‐skin electrode arrays are combined with flexible ECG sensors for stable 12‐lead ECG monitoring.

Evaluation of rheological behavior of asphalt mixtures modified with triblock polymers grafted maleic anhydride and montmorillonite clay

AbstractThis work presents an investigation of the incorporation of maleic anhydride (MAH)‐grafted triblock copolymers and montmorillonite clay (Mt) as modifiers of asphalt. A series of unmodified copolymers styrene‐butadiene‐styrene (SBS), styrene‐isoprene‐styrene (SIS), or styrene‐ethylene/butylene‐styrene (SEBS) with clay were prepared by direct mixing of all components. Subsequently, they were compared with their grafted‐MAH copolymer counterparts. The asphalt blends were characterized with respect to their rheological, morphological, and physical properties. Experimental results revealed that SBS and SIS grafted‐copolymer composites increase the softening point by 1.5%–7%, while the penetration decreases by 2%–15% in comparison to the homologous nongrafted polymers. The improvement can be directly linked to the continuous network polymer in the asphalt blends. The combined use of styrene‐isoprene‐styrene‐g‐MAH (SIS‐g‐MAH) copolymer and clay impart higher elastic behavior than that of the other blends. G′ increases about 95% in comparison to that of SIS/Mt, while the complex viscosity is three decades larger in the low frequencies region. Elevated rutting resistance temperature (&gt;100°C), tanδ &lt;5, reveals a solid‐like behavior with no Newtonian plateau. SEBS‐g‐MAH/Mt presents diminished rheological properties with respect to those of SEBS/Mt due to poor dispersion and agglomeration of clay particles in the polymer and asphalt matrix.

Multimodal health monitoring via a hierarchical and ultrastretchable all-in-one electronic textile

Wearable electronics with conductive yet stretchable bio-interfaces, multimodal health regulating capabilities, and strong weather resistance are especially expected by athletes and outdoor workers, yet conventional rigid, impermeable, and monofunctional wearables can hardly meet these requirements simultaneously. Here, a hierarchical and ultrastretchable all-in-one health-regulating electronic textile (AIO E-textile) with robust superhydrophobic and antibacterial surfaces is developed through electrospin-assisted layer-by-layer assembly and liquid metal (LM) printing. Skin-like and bio-compatible styrene-ethylene-butylene-styrene (SEBS) nonwoven textile is employed as a breathable matrix for the layered E-textile, in which an electrophysiological recording circuit, a strain-sensing circuit, and a Joule heating circuit are successively patterned using EGaIn. To ensure human skin health and weather resistance of the device, antibacterial and waterproof surfaces are respectively installed on both sides of the electronic textile via anchoring functionalized nanoparticles. Thus, this ultrastretchable (1141 %) AIO E-textile shows favorable moisture permeability (1300 g m−2 day), exceptional water repellency, remarkable antibacterial efficacy (>99.99 %) against E-coli, and low-watt Joule heating ability, which even exhibits accurate under-water motion detection capability, and high-definition acquiring of bioelectrical signals (electrocardiogram (ECG) and surface electromyography (sEMG)) when used as flexible epidermal bioelectrode. This work opens up a new avenue for daily applicable and multifunctional on-skin electronics.

Experimental investigations into additive manufacturing of styrene-ethylene-butylene-styrene block copolymers using solvent cast 3D printing technique

PurposeThis paper aims to discuss the successful 3D printing of styrene–ethylene–butylene–styrene (SEBS) block copolymers using solvent-cast 3D printing (SC-3DP) technique.Design/methodology/approachThree different Kraton grade SEBS block copolymers were used to prepare viscous polymer solutions (ink) in three different solvents, namely, toluene, cyclopentane and tetrahydrofuran. Hansen solubility parameters (HSPs) were taken into account to understand the solvent–polymer interactions. Ultraviolet–visible spectroscopy was used to analyze transmittance behavior of different inks. Printability of ink samples was compared in terms of shape retention capability, solvent evaporation and shear viscosity. Dimensional deviations in 3D-printed parts were evaluated in terms of percentage shrinkage. Surface morphology of 3D-printed parts was investigated by scanning electron microscope. In addition, mechanical properties and rheology of the SC-3D-printed SEBS samples were also investigated.FindingsHSP analysis revealed toluene to be the most suitable solvent for SC-3DP. Cyclopentane showed a strong preferential solubility toward the ethylene–butylene block. Microscopic surface cracks were present on tetrahydrofuran ink-based 3D-printed samples. SC-3D-printed samples exhibited high elongation at break (up to 2,200%) and low tension set (up to 9%).Practical implicationsSC-3DP proves to be an effective fabrication route for complex SEBS parts overcoming the challenges associated with fused deposition modeling.Originality/valueTo the best of authors’ knowledge, this is the first report investigating the effect of different solvents on physicomechanical properties of SC-3D-printed SEBS block copolymer samples.

Carbon Nanotube Migration in a Compatibilized Blend System, Leading to Kinetically Induced Enhancement in Electrical Conductivity and Mechanical Properties

Kinetic factors that facilitate carbon nanotube (CNT) migration in a polymer blend from a high-density polyethylene (HDPE) phase to a poly (p-phenylene ether) (PPE) phase were studied, with the objective to induce CNT migration and localization at the interface. Herein, a CNT filler was pre-localized in an HDPE polymer and then blended with PPE at different blend compositions of 20:80, 40:60, 60:40, and 80:20 of PPE/HDPE at a constant filler concentration of 1 wt%. The level of CNT migration was studied at different mixing times of 5 and 10 min. The electrical conductivity initially increased by 2-3 orders of magnitude, with an increase in the PPE content up to 40%, and then it decreased significantly by up to 12 orders of magnitude at high PPE content up to 100%. We determined that the extent of migration was related to the difference in the melt viscosity between the constituent polymers. A triblock copolymer styrene-ethylene/butylene-styrene (SEBS) was used to improve the blend miscibility, and 2 wt% copolymer was found to be the optimum concentration for the electrical properties for the two blend compositions of 20:80 and 80:20 of PPE/HDPE, at a constant filler concentration of 1 wt%. The introduction of the SEBS triblock copolymer significantly increased the conductivity almost by almost four orders of magnitude for PPE/HDPE/80:20 composites with 1 wt% CNT and 2 wt% SEBS compared to the uncompatibilized blend nanocomposite. The mechanical strength of the compatibilized blend nanocomposites was found to be higher than the unfilled compatibilized blend (i.e., without CNT), uncompatibilized blend nanocomposites, and the pristine blend, illustrating the synergistic effect of adding nanofillers and a compatibilizer. SEM and TEM microstructures were used to interpret the structure-property relationships of these polymer blend nanocomposites.

A novel form-stable phase change material based on elastomeric copolymer and carbon nanotubes with photo-thermal conversion performance

In this paper, the composite form-stable phase change materials (FSPCMs) with a photo-thermal conversion function for solar thermal energy storage were prepared using paraffin wax (PW) as a PCM, both styrene ethylene butylene styrene (SEBS) and olefin block copolymer (OBC) as supporting materials, and carbon nanotubes (CNT) as an efficient light-absorbing material. The PW/SEBS + OBC composite with 80 wt% PW can maintain a stable shape without leakage above the phase change temperature. The latent heat of the PW/SEBS + OBC/CNT composite with 8 % CNT is 136.2 J/g, and the entrapment efficiency is 71.2 %. The prepared composite FSPCMs have good flexibility, thermal reliability, and thermal stability. And the absorbance of PW/SEBS + OBC/CNT composite is higher than that of pure PW and PW/SEBS + OBC. Moreover, the photo-thermal conversion efficiency of PW/SEBS + OBC/CNT composite with 2 wt% CNT, 4 wt% CNT, 6 wt% CNT, and 8 wt% CNT is 72.9 %, 81.9 %, 82.3 %, and 83.2 %, respectively. The prepared composite FSPCMs have a promising application in the field of solar energy storage.

Toughening of linear low-density polyethylene/brominated polystyrene blend by styrene-ethylene/butylene-styrene elastomer

Brominated polystyrene (BPS) is blended with linear low-density polyethylene (LLDPE) to improve its fire retardancy for various applications such as wire and cable covering. To improve compatibility and mechanical properties, styrene-ethylene/butylene-styrene (SEBS) copolymer was added as a compatibilizer. The influence of processing temperature and SEBS elastomer on morphology, interfacial and mechanical properties has been investigated. It was found that melt blending at 230 °C with addition of SEBS elastomer can significantly reduce the BPS particle size to less than 0.5 μm by forming a core-shell structure that enhances the interfacial strength between BPS and LLDPE phases. Addition of 8 phr SEBS elastomer can increase the Izod impact strength at −37 °C by a factor of nearly three, compared to the non-compatibilized LLDPE/BPS system. Double-notch four-point bending (DN-4PB) test reveals that crazing and shear banding are two primary toughening mechanisms for the observed increase in the low temperature impact strength.