Styrene Ethylene Butadiene Research Articles

Trimethylsilane Plasma-Nanocoated Silver Nanowires for Improved Stability.

The objective of this study was to evaluate the effectiveness of trimethylsilane (TMS) plasma nanocoatings in protecting silver nanowires (AgNWs) from degradation and thus to improve their stability. TMS plasma nanocoatings at various thicknesses were deposited onto AgNWs that were prepared on three different substrates, including glass, porous styrene-ethylene-butadiene-styrene (SEBS), and poly-L-lactic acid (PLLA). The experimental results showed that the application of TMS plasma nanocoatings to AgNWs induced little increase, up to ~25%, in their electrical resistance but effectively protected them from degradation. Over a two-month storage period in summer (20-22 °C, 55-70% RH), the resistance of the coated AgNWs on SEBS increased by only ~90%, compared to a substantial increase of ~700% for the uncoated AgNWs. On glass, the resistance of the coated AgNWs increased by ~30%, versus ~190% for the uncoated ones. When stored in a 37 °C phosphate-buffered saline (PBS) solution for 2 months, the resistance of the coated AgNWs on glass increased by ~130%, while the uncoated AgNWs saw a ~970% rise. Increasing the TMS plasma nanocoating thickness further improved the conductivity stability of the AgNWs. The nanocoatings also transformed the AgNWs' surfaces from hydrophilic to hydrophobic without significantly affecting their optical transparency. These findings demonstrate the potential of TMS plasma nanocoatings in protecting AgNWs from environmental and aqueous degradation, preserving their electrical conductivity and suitability for use in transparent electrodes and wearable electronics.

Experimental Investigation of Processing Temperature Effect on Adhesive Bond Strength Between Engineering Thermoplastics in the Plastic Injection Molding Process

Abstract Multicomponent injection molding industry is experiencing a growth due to its ability to reduce production costs and streamline processes. However, compared to single injection, multicomponent injection molding introduces interface regions where multiple engineering polymers meet. Consequently, it is essential to comprehend and enhance the adhesive bonding strength properties of these polymers. This study investigates the adhesive bond strength of polymer–polymer multimaterial molding using two-shot bi-injection and overmolding techniques. The research also emphasizes the influence of injection molding process parameters of mold temperature and melt temperature on the adhesive bond strength of polycarbonate (PC), polycarbonate–acrylonitrile butadiene styrene (PC–ABS), acrylonitrile butadiene styrene (ABS), and styrene ethylene butadiene styrene (SEBS). Tensile strength results revealed that the bi-injection method yields the highest interface strength, approximately 10 MPa lower than the reference value for single-material hard–hard plastics. Results from overmolded samples for both injection sequences are presented, indicating that material with low melting temperature was found to be the first injected part for better adhesion strength. Empirical equations for estimating adhesion strength were derived as a function of interface temperature obtained from CAE numerical simulations and polymer glass transition temperatures. The proposed equation achieved R2 values greater than 0.96. This empirically derived equation will serve as a guide for multi-injection manufacturing processes.

High sensitivity flexible organic X-ray detectors with minor TIPS-pentacene/insulator polymer blend active layer

A new class of flexible X-ray sensor in which there is a vertical structure with the active layer of minor 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) blending into styrene-ethylene-butadiene-styrene (SEBS) has been developed. The minor TIPS-pentacene to enhance the sensitivity of 1137.2 μCGyair−1 cm−2 and low detection limit of 47.91 nGyair s−1 because of the higher attenuation coefficient and photocurrent gain effect in the hybrid active layer. The stability and flexibility of this organic detector are attributed to the plasticity of SEBS and encapsulation of TIPS-pentacene. This work highlights the potential exploitation of high-performance future innovative flexible and highly sensitive direct X-ray detectors.

Salt resistant and self‐cleaning CNTs‐SEBS‐MAH composite membrane for seawater desalination

AbstractSolar‐driven steam generation membranes have garnered increasing attention for freshwater production. Nonetheless, the adverse impact of salt accumulation on membrane surfaces directly undermines the efficacy of solar evaporation. In this work, one type of composite membrane comprised of carbon nanotubes (CNTs)‐styrene‐ethylene‐butadiene‐styrene (SEBS) was fabricated by modified vapor phase pore‐forming technique. Through the grafting of maleic anhydride (MAH), the CNTs‐SEBS‐MAH composite membrane was successfully hydrolyzed. As a consequence, the composite membrane exhibits evaporation rate as high as 1.28 kg m−2 h−1 under one sun solar irradiation, accompanied by an outstanding solar vapor conversion efficiency of 87.5%. In addition, the fabricated composite membrane has high resistance to salt accumulation, as well as self‐cleaning capability. This work provides a route for manufacturing hydrophilic polymer composite membrane towards solar energy driven seawater desalination.

Mouldable Conductive Plastic with Optimised Mechanical Properties.

This paper investigates making an injection mouldable conductive plastic formulation that aims for conductivity into the electromagnetic interference (EMI) shielding range, with good mechanical properties (i.e., stiffness, strength, and impact resistance). While conductivity in the range (electrostatic charge dissipation) and EMI shielding have been attained by incorporating conductive fillers such as carbon black, metals powders, and new materials, such as carbon nanotubes (CNTs), this often occurs with a drop in tensile strength, elongation-to-break resistance, and impact resistance. It is most often the case that the incorporation of high modulus fillers leads to an increase in modulus but a drop in strength and impact resistance. In this work, we have used short carbon fibres as the conductive filler and selected a 50/50 PBT/rPET (recycled PET) for the plastic matrix. Carbon fibres are cheaper than CNTs and graphenes. The PBT/rPET has low melt viscosity and crystallises sufficiently fast during injection moulding. To improve impact resistance, a styrene-ethylene-butadiene-styrene (SEBS) rubber toughening agent was added to the plastic. The PBT/rPET had very low-impact resistance and the SEBS provided rubber toughening to it; however, the rubber caused a drop in the tensile modulus and strength. The short carbon fibre restored the modulus and strength, which reached higher value than the PBT/rPET while providing the conductivity. Scanning electron microscope pictures showed quite good bonding of the current filler (CF) to the PBT/rPET. An injection mouldable conductive plastic with high conductivity and raised modulus, strength, and impact resistance could be made.

Mechanical Anisotropy of Injection-Molded PP/PS Polymer Blends and Correlation with Morphology.

The molecular orientation formed by melt-forming processes depends strongly on the flow direction. Quantifying this anisotropy, which is more pronounced in polymer blends, is important for assessing the mechanical properties of thermoplastic molded products. For injection-molded polymer blends, this study used short-beam shear testing to evaluate the mechanical anisotropy as a stress concentration factor, and clarified the correlation between the evaluation results and the phase structure. Furthermore, because only shear yielding occurs with short-beam shear testing, the yielding conditions related to uniaxial tensile loading were identified by comparing the results with those of three-point bending tests. For continuous-phase PP, the phase structure formed a sea-island structure. The yield condition under uniaxial tensile loading was interface debonding. For continuous-phase PS, the phase structure was dispersed and elongated in the flow direction. The addition of styrene-ethylene-butadiene-styrene (SEBS) altered this structure. The yielding condition under uniaxial tensile loading was shear yielding. The aspect ratio of the dispersed phase was found to correlate with the stress concentration factor. When the PP forming the sea-island structure was of continuous phase, the log-complex law was sufficient to explain the shear yield initiation stress without consideration of the interfacial interaction stress.

Recycling of HIPS and multilayer films with SEBS-based additives

With the evolution of new polymers and an increase in their scope of applications, the use of natural resources such as petroleum products for polymer production has seen a drastic increase in the past few years. With production rates higher than ever and rapid, unsafe disposal of used polymers has taken a toll on the environment and other species through pollution. Even though there are alternative solutions, including bioplastics manufactured from greener sources and biodegradable plastics that can disintegrate in a shorter time period, these alternatives are currently in their early stages and hence expensive. It is also more challenging for them to meet the high demands in terms of both quantity and properties. The next nearest alternative, recycling, is the best available solution to avoid plastic waste entering landfills and to reduce raw material demands. This study aims to determine the effectiveness of a newly introduced styrene–ethylene–butadiene block copolymer (SEBS)-based property enhancer (WinMod 300) with disposed high-impact polystyrene (HIPS) and a maleic anhydride-grafted SEBS compatibilizer (WinMod 110) with disposed multilayer films (low-density polyethylene and polyester layers). Recycled compounds were tested for necessary and significant mechanical properties and subjected to material characterization, and the results are presented in this paper.

Paintable Silicone-Based Corrugated Soft Elastomeric Capacitor for Area Strain Sensing.

Recent advances in soft polymer materials have enabled the design of soft machines and devices at multiple scales. Their intrinsic compliance and robust mechanical properties and the potential for a rapid scaling of the production process make them ideal candidates for flexible and stretchable electronics and sensors. Large-area electronics (LAE) made from soft polymer materials that are capable of sustaining large deformations and covering large surfaces and are applicable to complex and irregular surfaces and transducing deformations into readable signals have been explored for structural health monitoring (SHM) applications. The authors have previously proposed and developed an LAE consisting of a corrugated soft elastomeric capacitor (cSEC). The corrugation is used to engineer the directional strain sensitivity by using a thermoplastic styrene-ethylene-butadiene-styrene (SEBS). A key limitation of the SEBS-cSEC technology is the need of an epoxy for reliable bonding of the sensor onto the monitored surface, mainly attributable to the sensor's fabrication process that comprises a solvent that limits its direct deployment through a painting process. Here, with the objective to produce a paintable cSEC, we study an improved solvent-free fabrication method by using a commercial room-temperature-vulcanizing silicone as the host matrix. The matrix is filled with titania particles to form the dielectric layer, yielding a permittivity of 4.05. Carbon black powder is brushed onto the dielectric and encapsulated with the same silicone to form the conductive stretchable electrodes. The sensor is deployed by directly painting a layer of the silicone onto the monitored surface and then depositing the parallel plate capacitor. The electromechanical behavior of the painted silicone-cSEC was characterized and exhibited good linearity, with an R2 value of 0.9901, a gauge factor of 1.58, and a resolution of 70 με. This resolution compared well with that of the epoxied SEBS-cSEC reported in previous work (25 με). Its performance was compared against that of its more mature version, the SEBS-cSEC, in a network configuration on a cantilever plate subjected to a step-deformation and to free vibrations. Results showed that the performance of the painted silicone-sCEC compared well with that of the SEBS-cSEC, but that the use of a silicone paint instead of an epoxy could be responsible for larger noise and the under-estimation of the dominating frequency by 6.7%, likely attributable to slippage.

78‐3: Piezoresistive Area Sensor with Polymer and CNTs Mixture on Oxide TFT Backplane

We demonstrate a highly sensitive, lateral pressure sensor using carbon nanotubes (CNTs) embedded in styrene‐ethylene‐butadiene‐styrene (SEBS) layer on 48 x 48 AM backplane for pressure mapping. The sensor exhibits highly sensitive, piezoresistive performances with current ratio of ~10 6 with a broad detection range of 330 Pa to 28 kPa, and response and recovery times of less than 10 ms and 20 ms, respectively.

Study of the effect of different functionalized magnesium hydroxide prepared by mechanochemical method on the flame retardancy and mechanical properties of styrene‐ethylene‐butadiene‐styrene/polypropylene composites

AbstractSolvent‐free synthetic methods have received more attention because of their reducing chemical waste and simplifying the process. A series of functionalized magnesium hydroxides (FMHs) were successfully modified with siloxanes containing different functional groups (Octyl: OTES, Octadecyl: OTMS, Phenyl: PTMS, Vinyl: VTEO, and 3‐Aminopropyl: APS) via a solvent‐free mechanochemical method. Ball milling conditions (such as reaction time, siloxane/MH ratio), the morphology, surface properties and particle size of the FMHs were investigated in detail and the results showed that both of the adjustment of particle size and the modification of surface of MH were successfully achieved at one time within 20 min. All FMHs were successfully converted from hydrophilic to hydrophobic except for the sample modified by the silane containing APS group. The influence of the different functional groups and particle size of FMHs on the mechanical properties and flame retardancy of styrene‐ethylene‐butadiene‐styrene (SEBS)/polypropylene (PP) composites were discussed. Compared with original MH/SEBS/PP, the FMHs/SEBS/PP composites have better tensile strength and elongation at break. When 68 wt% of FMHs were added to the SEBS/PP matrix, the composites can pass V‐0 rating of UL‐94 testing, and their limiting oxygen index values are above 32.3%. Meanwhile, the composites also exhibited strong smoke suppression.

Research on preparation and properties of pH responsive superhydrophobic coating modified by SEBS

Smart materials with reversible wettability have attracted a lot of attention for application in sewage treatment. In this work, a pH-responsive polymer was prepared via the one-step free radical polymerization of 3-(trimethoxysilyl) acrylate and 2-dimethylaminoethyl methacrylate. The obtained pH-responsive polymer was then coated with a hydrogenated styrene–ethylene–butadiene–styrene block copolymer to endow the material with pH-responsive switchable superhydrophilic and superhydrophobic properties. Due to the excellent self-cleaning and mechanical stability of the coating, it was used to modify paper, which was then successfully utilized in the treatment of oily wastewater, showing great potential for use in advanced applications.

Montmorillonite nanokil ilave edilmiş düşük yoğunluklu polietilen/polistiren/stiren bütadien stiren polimer kompozitinin fiziksel ve aşınma özelliklerinin incelenmesi

In this study; a polymer composite was produced by adding different proportions of polystyrene (PS), styrene ethylene butadiene styrene thermoplastic block copolymer (SBS) and montmorillonite nanoclay into low density polyethylene (LDPE). Six different polymer composites were produced by mixing all materials in a twin screw extruder. Later, standard test samples were molded from the obtained polymer composites by injection molding method. To learn about the various physical and wear properties of polymer composite materials obtained; Vicat softening temperature, moisture content, melt flow index (MFI), thermal deflection temperature (HDT), friction coefficient, density and wear tests were performed. In addition, in order to see the distribution of montmorillonite in the polymer matrix, microstructure photographs were taken with scanning electron microscopy (SEM) by using fracture surfaces of impact test samples. According to the results obtained from the tests carried out, which are included in low density polyethylene matrix; It has been determined that there are significant changes in the physical and abrasion values of the polymer composite with the change of PS, SBS and nano clay ratios.

Exploring the effect of block copolymer architecture and concentration on the microstructure, electrical conductivity and rheological properties of PP/PS blend nanocomposites

The interface between polymer matrices and nanofillers is critical for efficient interaction to achieve the desired final properties. In this work, block copolymers were utilized to control the interface and achieve optimum interfacial interaction. Specifically, we studied the compatibilizing effects of styrene-ethylene/butadiene-styrene (SEBS) and styrene-ethylene/propylene (SEP) block copolymers on the morphology, conductivity, and rheological properties of polypropylene-polystyrene (PP/PS) immiscible blend with 2 vol% multiwall carbon nanotube (MWCNT) at different blend compositions of PP/PS 80:20, 50:50 and 20:80.MWCNTs induced co-continuity in PP/PS blends and did not obstruct with the copolymer migration to the interface. Copolymers at the interface led to blend morphology refinement. Adding block copolymers at a relatively low concentration of 1 vol% to compatibilize the PP/PS 80:20 blend substantially increased the electrical conductivity from 5.15*10−7S/cm for the uncompatibilized blend to 1.07*10−2S/cm for the system with SEP and 1.51*10−3S/m for the SEBS system. These values for the compatibilized blends are about 4 orders of magnitude higher due to the interconnection of the droplet domains. For the PP/PS 50:50 blend, the SEBS copolymer resulted in a huge increase in conductivity at above 3 vol% concentration (conductivity increased to 3.49*10−3S/cm from 5.16*10−7S/cm). Both the conductivity and the storage modulus increased as the SEBS copolymer content was increased. For the PP/PS 20:80 blend, we observed an initial decrease in conductivity at lower copolymer concentrations (1–3 vol%) and then an increase in conductivity to values higher than the uncompatibilized system, but only at a higher copolymer concentration of 10 vol%. The triblock copolymer (SEBS), which had 60 wt% PS content, shows a more significant increase in rheological properties compared to the diblock copolymer (SEP). The morphology shows that the interaction between MWCNT and PS is stronger than the interaction between MWCNT and PP, hence there is selective localization of the nanofiller in the PS phase as predicted by Young’s equation and by molecular simulation.

Acid treated halloysite nanotubes reinforced PP/ABS blends and its composites: Influence on mechanical and thermal properties

Halloysite nanotube (HNTs) is treated with sulphuric acid (H2SO4) which results in the formation of amorphous silica over the HNTs surface. The acid-treated HNTs and untreated HNTs are reinforced in a ratio of 80:20 (wt/wt) of polypropylene (PP) to acrylonitrile butadiene styrene (ABS) blends using melt extrusion. The dual compatibilizers of grafted maleic anhydride monomer over polypropylene and styrene ethylene butadiene styrene are used as compatibilizers for compatibilizing HNTs filled blend and its composites. The cryofractured and etched HTNs filled blends and its composites reveal the development of droplet embedded in the matrix. A significant decrease in average droplet diameter is observed with the incorporation of acid-treated HNTs and untreated HNTs filled blends and its composites. Acid-treated HNTs and pure HNTs filled blends and its composites influence the crystallinity of the PP phase as compared to pure blends. In addition, it has influenced thermal stability. The refined morphology and compatibilization improves the tensile and impact properties of untreated HNTs and acid-treated HNTs filled blends and its composites in comparison to pure blend. Tensile fractured scanning electron microscope (SEM) image shows the formation of fibrils. Whereas the impact fractured SEM image shows the resistance to dislodge the ABS droplets. Acid-treated HNTs filled blends and its composites show the highest tensile and impact properties with ∼37% increase in tensile modulus and ∼49% increase in impact strength in comparison to pure blends.

Poly(2,6-dimethyl-1,4-phenylene ether)/poly(phenylene sulfide)/styrenic block copolymer blends compatibilized with reactive polystyrene

Blends of poly(2,6-dimethyl-1,4-phenylene ether) (PPE) and poly(phenylene sulfide) (PPS) have shown potential as a new class of high-performance engineering plastics by reciprocally complementing the drawbacks of each component. However, improving their inherently poor toughness remains a challenge. Here, we report the design of PPE/PPS-based quaternary blends with increased impact strength without a significant loss of mechanical and flame-retardant properties. Introducing reactive polystyrene (RPS) with an oxazoline functional group as a compatibilizer improved the miscibility between the discrete PPE domain and continuous PPS matrix phases. The impact modifier styrene-ethylene-butadiene-styrene (SEBS) was compatibilized within the PPS matrix phase in the presence of RPS, enabling extraordinary impact strength. The tensile strength of the quaternary blends decreased slightly with increasing SEBS content, but the values exceeded the criteria for engineering plastic. All quaternary blends passed the V-0 grade in the UL-94 test because of the inherently excellent flame retardancy of the majority components.

Estimation of mechanical properties of LDPE/LLDPE/SEBS nanocomposite reinforced with calcium carbonate nanoparticles by Ch mathematical model

Doing experiments in order to determine mechanical properties of nanocomposites costs a lot. Therefore, finding the ways by which the properties of the nanocomposites can be predicted without any empirical or few number of empirical experiments seems to be useful. In the present study, efforts have been made to create a relation between mathematical model based on dimensionless number (Ch) and mechanical properties of low-density polyethylene/linear low-density polyethylene/styrene ethylene butadiene styrene (LDPE/LLDPE/SEBS) nanocomposite reinforced by nanoparticles of calcium carbonate. The proposed model is able to predict mechanical properties of nanocomposites based on their composition. This model is capable to predict elongation at break in terms of Young’s modulus and fracture toughness, and to predict fracture toughness in terms of Young’s modulus and elongation at break. The results showed prediction of the dimensionless number Ch model, and the experimental results are consistent.

Preparation and balanced mechanical properties of solid and foamed isotactic polypropylene/SEBS composites

AbstractThis study presents a self‐designed foaming apparatus and routes to manufacture foamed isotactic polypropylene (iPP) blends with uniform and dense cells, using styrene‐ethylene‐butadiene‐styrene (SEBS) block copolymer as toughening additive. The addition of SEBS can clearly enhance the impact strength of solid iPP, iPP blends with a 20 wt% SEBS has obtained high notched impact strength of 75 kJ/m2, which is ca. 16 times larger than that of neat iPP. Relatively fine microcellular iPP‐SEBS foams with the average cell size of several micrometers, and the cell density of 109 cells/cm3 were fabricated using a batch foaming procedure. Moreover, using our self‐designed mold and compression foaming method, iPP‐SEBS foams with balanced mechanical properties were produced. With the increasing of SEBS, tensile strength and flexural strength were slightly decreased, but the impact strength was increased clearly. The balanced mechanical properties between stiffness and toughness were achieved after compression foaming.

Triboelectric Energy Harvesting Response of Different Polymer-Based Materials.

Energy harvesting systems for low-power devices are increasingly being a requirement within the context of the Internet of Things and, in particular, for self-powered sensors in remote or inaccessible locations. Triboelectric nanogenerators are a suitable approach for harvesting environmental mechanical energy otherwise wasted in nature. This work reports on the evaluation of the output power of different polymer and polymer composites, by using the triboelectric contact-separation systems (10 N of force followed by 5 cm of separation per cycle). Different materials were used as positive (Mica, polyamide (PA66) and styrene/ethylene-butadiene/styrene (SEBS)) and negative (polyvinylidene fluoride (PVDF), polyurethane (PU), polypropylene (PP) and Kapton) charge materials. The obtained output power ranges from 0.2 to 5.9 mW, depending on the pair of materials, for an active area of 46.4 cm2. The highest response was obtained for Mica with PVDF composites with 30 wt.% of barium titanate (BT) and PA66 with PU pairs. A simple application has been developed based on vertical contact-separation mode, able to power up light emission diodes (LEDs) with around 30 cycles to charge a capacitor. Further, the capacitor can be charged in one triboelectric cycle if an area of 0.14 m2 is used.

Effects of Porosity and SEBS Fraction on Dry Sliding Friction of EVA Foams for Sports Shoe Sole Applications

Ethylene vinyl acetate (EVA) foam is sometimes used in the outer soles of sport shoes. To improve the slip resistance of EVA foam, this study investigated the effects of porosity and the fraction of styrene–ethylene–butadiene–styrene (SEBS) on the dry sliding friction behavior of EVA foams. Sliding friction tests were performed against a pin specimen with a semicylindrical tip, which was covered with (rough surface) or without abrasive paper (smooth surface). The results revealed that the friction coefficient of the EVA foam increased with porosity when slid against a smooth surface, whereas its friction coefficient increased with porosity and SEBS fraction when slid against a rough surface. The results of this investigation provide insight into how to increase the dry sliding friction of resin foam against smooth and rough surfaces, which will also contribute to improving the slip resistance of shoe soles made from resin foam.

Rubber toughened recycled polyethylene terephthalate for material extrusion additive manufacturing

AbstractPlastic packaging materials represent a new class of low‐cost and sustainable additive manufacturing feedstocks. Recycled polyethylene terephthalate (PET) has been shown to be a robust material for material extrusion additive manufacturing, with mechanical properties comparable with acrylonitrile‐butadiene‐styrene. However, due to PET's high crystallinity, it is generally a brittle material and can be subject to premature fracture. It is well known that the addition of rubbers can serve to toughen PET. In this work, micronized rubber powder, as well as non‐reactive and functionalized styrene‐ethylene‐butadiene‐styrene (SEBS) elastomers were compounded with recycled PET. Tensile strength was not significantly affected, but toughness increased 85% with the addition of 5 wt% rubber, 350% with SEBS and over 550% with maleic anhydride functionalized SEBS compared to neat recycled PET. Fracture surface analysis revealed evidence of ductile fracture and cavitation in the rubber toughened samples. Published 2020. This article is a U.S. Government work and is in the public domain in the USA