Aliphatic Segments Research Articles

Dissolved Black Carbon Facilitates the Photodegradation of Microplastics via Molecular Weight-Dependent Generation of Reactive Intermediates.

Photodegradation of microplastics (MPs) induced by sunlight plays a crucial role in determining their transport, fate, and impacts in aquatic environments. Dissolved black carbon (DBC), originating from pyrolyzed carbon, can potentially mediate the photodegradation of MPs owing to its potent photosensitization capacity. This study examined the impact of pyrolyzed wood derived DBC (5 mg C/L) on the photodegradation of polystyrene (PS) MPs in aquatic solutions under UV radiation. It revealed that the photodegradation of PS MPs primarily occurred at the benzene ring rather than the aliphatic segments due to the fast attack of hydroxyl radical (•OH) and singlet oxygen (1O2) on the benzene ring. The photosensitivity of DBC accelerated the degradation of PS MPs, primarily attributed to the increased production of •OH, 1O2, and triplet-excited state DBC (3DBC*). Notably, DBC-mediated photodegradation was related to its molecular weight (MW) and chemical properties. Low MW DBC (<3 kDa) containing more carbonyl groups generated more •OH and 1O2, accelerating the photodegradation of MPs. Nevertheless, higher aromatic phenols in high MW DBC (>30 kDa) scavenged •OH and generated more O2•-, inhibiting the photodegradation of MPs. Overall, this study offered valuable insights into UV-induced photodegradation of MPs and highlighted potential impacts of DBC on the transformation of MPs.

Unveiling intermolecular mechanism and electronic properties between asphaltene and deep eutectic solvent for enhanced oil recovery using first principles calculation

Electronic structure and interaction energy calculations offer critical insights into non-bonded interactions in solute–solvent systems that can be used to extract heavy oil, particularly asphaltene, in enhanced oil recovery. The present study examines deep eutectic solvent (DES) interaction with asphaltene through first-principles calculations, revealing the role of hydrogen bonds, overall system stability, and its mechanism. The analysis reveals that the inclusion of asphaltene makes the DES-asphaltene structure less stable, i.e., increasing wettability with DES. DES formed non-bonded interactions with asphaltene's aliphatic segments but excluded aromatic rings due to strong π-π interactions. Among the studied DESs, DES1 (choline chloride and urea, 1:2 ratio) exhibited a strong interaction with asphaltene (-103.946 kJ/mol) and formed a hydrogen bond. All systems show negative binding energies, which indicate stability. Notably among them, DES2 (choline chloride and thiourea, 1:2) and DES3 (choline chloride and ethylene glycol, 1:2) displayed remarkable stability with asphaltene, evident in a widened band gap of 2.182 and 2.157 eV, respectively.

A sulfonated polyimide containing flexible aliphatic segments with high chemical stability for vanadium redox flow battery application

To improve sulfonated polyimide (SPI) chemical stability, the SPI containing flexible aliphatic segments is successfully designed and synthesized. The highest occupied molecular orbital (HOMO) energy, lowest unoccupied molecular orbital (LUMO) energy and their energy gaps (HOMO-LUMO gap (ΔE)) can quantitatively compare the molecular reactivity, which are calculated and used to compare firstly in the SPIs for vanadium redox flow battery (VRFB) application. Furthermore, the natural bond orbital (NBO) charge of SPIs is also used to calculate and compare, respectively. Theoretical calculation shows SPI(DAD) has higher chemical stability. Obtained by experimental results that the retention time in water of SPI(DAD)-60 membrane is 23.58 h at 80 °C, which is nearly four times than conventional SPI under the same conditions. The SPI(DAD)-60 membrane at a current density of 100 mA cm−2 shows higher columbic efficiency (CE: 96.83%), and energy efficiency (EE: 79.47%) than that of N212 membrane (CE: 93.14%, EE: 74.13%). Besides, the SPI(DAD)-60 membrane has 479.1 mA h more charging capacity after 100 cycles compared to N212 membrane. The theoretical calculation of the LUMO energy, HOMO-LUMO gap may be a potential tool that is used to analyze and evaluate the chemical stability of membranes for VRFB application.

Aliphatic Polybenzimidazoles: Synthesis, Characterization and High-Temperature Shape-Memory Performance

A series of aliphatic polybenzimidazoles (PBIs) with methylene groups of varying length were synthesized by the high-temperature polycondensation of 3,3'-diaminobenzidine (DAB) and the corresponding aliphatic dicarboxylic acid in Eaton's reagent. The influence of the length of the methylene chain on PBIs' properties was investigated by solution viscometry, thermogravimetric analysis, mechanical testing and dynamic mechanical analysis. All PBIs exhibited high mechanical strength (up to 129.3 ± 7.1 MPa), glass transition temperature (≥200 °C) and thermal decomposition temperature (≥460 °C). Moreover, all of the synthesized aliphatic PBIs possess a shape-memory effect, which is a result of the presence of soft aliphatic segments and rigid bis-benzimidazole groups in the macromolecules, as well as strong intermolecular hydrogen bonds that serve as non-covalent crosslinks. Among the studied polymers, the PBI based on DAB and dodecanedioic acid has high adequate mechanical and thermal properties and demonstrates the highest shape-fixity ratio and shape-recovery ratio of 99.6% and 95.6%, respectively. Because of these properties, aliphatic PBIs have great potential to be used as high-temperature materials for application in different high-tech fields, including the aerospace industry and structural component industries.

Design of P-decorated POSS towards flame-retardant, mechanically-strong, tough and transparent epoxy resins

Epoxy resins (EPs) are known for their durability, strength, and adhesive properties, which make them a versatile and popular material for use in a variety of applications, including chemical anticorrosion, small electronic devices, etc. However, EP is highly flammable due to its chemical nature. In this study, phosphorus-containing organic–inorganic hybrid flame retardant (APOP) was synthesized by introducing 9, 10-dihydro-9-oxa-10‑phosphaphenathrene (DOPO) into cage-like octaminopropyl silsesquioxane (OA-POSS) via Schiff base reaction. The improved flame retardancy of EP was achieved by combining the physical barrier of inorganic Si-O-Si with the flame-retardant capability of phosphaphenanthrene. EP composites containing 3 wt% APOP passed the V-1 rating with a value of LOI of 30.1% and showed an apparent reduction in smoke release. Additionally, the combination of the inorganic structure and the flexible aliphatic segment in the hybrid flame retardant provides EP with molecular reinforcement, while the abundance of amino groups facilitates a good interface compatibility and outstanding transparency. Accordingly, EP containing 3 wt% APOP increased in tensile strength, impact strength, and flexural strength by 66.0 %, 78.6 %, and 32.3 %, respectively. The EP/APOP composites had a bending angle lower than 90°, and their successful transition to a tough material highlights the potential of this innovative combination of the inorganic structure and the flexible aliphatic segment. In addition, the relevant flame-retardant mechanism revealed that the APOP promoted the formation of a hybrid char layer containing P/N/Si for EP and produced phosphorus-containing fragments during combustion, showing flame-retardant effects in both condensed and vapor phases. This research offers innovative solutions for reconciling flame retardancy & mechanical performances and strength & toughness for polymers.

Synthesis and Fabrication of a Betulin-Containing Polyolefin Electrospun Fibrous Mat for Antibacterial Applications.

Biocompounds play a significant role in the area of renewable polymers in terms of sustainability, as they can be employed or converted into monomers for polymerization in a manner similar to many petroleum-derived monomers. In this work, betulin, a plant-derived triterpene with antibacterial and antiviral properties, was converted to two kinds of α,ω-diene derivatives with different methylene spacer lengths between the olefin and the ester group via an esterification reaction. Polyolefins were subsequently made by acyclic diene metathesis (ADMET) polymerization of betulin-based α,ω-diene. The polymer consists of rigid betulin and flexible unsaturated aliphatic segments, which was confirmed by NMR spectroscopy and gel permeation chromatography (GPC). The influence of different parameters including temperature, catalysts, and catalyst loading on ADMET polymerization was investigated. These polyolefins with high molar mass (up to 20.0 kg/mol) were obtained in an elevated yield (≥95%). Thermal analysis of these (co)polymers showed excellent thermal stability (up to 360 °C) and tunable glass transition temperatures depending on the nature of betulin and alkene segments. To evaluate the antimicrobial potential of betulin-containing polymers, the fabrication of polyolefin fibrous mats (ca. 400 nm diameter) via the electrospinning technique was successfully achieved. Their morphology and hydrophobicity were studied by scanning electron microscopy (SEM) and water contact angle analyses. The fibrous mats possessed broad-spectrum antibacterial property, providing a feasible strategy to design betulin-based polymeric fibers for many applications in the biomedical field.

Photocurable extended vanillin-based resin for mechanically and chemically recyclable, self-healable and digital light processing 3D printable thermosets

A vanillin-based photocurable resin was designed for circularity by incorporation of imine functionalities through a Schiff-base reaction between the aldehyde function of vanillin and amino group of ethylene diamine. Sufficient flexibility was provided by a short aliphatic segment introduced by reaction of vanillin with ethylene carbonate, while photocurability was obtained by subsequent methacrylation. The cured thermoset had good solvent resistance, relatively high glass transition temperature (∼75 °C) and good thermal stability with an onset of degradation above 300 °C. Due to the crosslinked structure and imine linkages, the thermoset expressed malleability, self-healing and thermal reprocessability. Furthermore, it could be chemically recycled by immersing in ethylene diamine, which activated transimination. The obtained oligomeric product with amine-terminal groups could be utilized for production of new thermoset films. Tensile testing illustrated similar elastic modulus for mechanically and chemically recycled thermosets, while a slight increase was observed for the self-healed samples, ascribable to a completion of the curing during the post-processing. At the same time elongation and stress at break slightly decreased. Finally, the suitability of the resin for the production of 3D objects by means of digital light processing (DLP) 3D printing was demonstrated.

Effect of aliphatic segment length and content on crystallization and biodegradation properties of aliphatic-aromatic co-polyesters

In this work, dimethyl terephthalate (DMT), 1,4-butanediol (BDO) and different diacids were introduced to investigate the effects of variations in aliphatic chain length and component content in aliphatic aromatic terpolymers on the basic thermal properties, crystalline morphology, mechanical properties and biodegradability of the polyesters. The experimental results from nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR) and Gel permeation chromatography (GPC) indicate the successful synthesis of the anticipated aliphatic aromatic co-polyesters. The variation of melting and crystallization temperatures with aliphatic chain segment length and content were analyzed by differential scanning calorimetry (DSC). The Wide-angle X-ray diffraction (WAXD) results suggest that the coexistence of both crystals formed by rigid and flexible chain segments can be achieved by varying the length and component content of the aliphatic chain segments in the co-polyesters. The scanning electron microscopy (SEM) and composting experiment results indicate that the type of crystals formed with the more flexible chain segments and the lower degree of crystallinity have a positive effect on the biodegradability.

Exploring highly soluble ether-free polybenzimidazole as anion exchange membranes with long term durability

A series of ether-free polybenzimidazoles (PBIs) containing alicyclic and aliphatic segments were synthesized for the application of anion exchange membranes (AEMs). The PBI-based AEMs prepared in this work (denoted as Pip-PBIs) possessed both high anionic conductivity and alkaline stability by grafting long alkyl chain 1-methylpiperidinium. Benefiting from the random arrangement of aromatic-alicyclic/aliphatic in backbone and their flexible spatial configurations, most Pip-PBIs showed significantly improved solubility in low boiling point solvents namely methanol and isopropanol, which could allow it as ionomer to improve the phase interface between catalyst and AEMs. Meanwhile, the flexible segments in backbone contributed to the formation of ion conductive channel, the Pip-PBI-C achieved the highest hydroxide ions conductivity of 108.8 mS cm −1 at 80 °C, and the conductivity could retain 82.9% after soaking in a 2 M aqueous NaOH at 80 °C for 1536 h. Furthermore, Pip-PBIs demonstrated well oxidation stability in Fenton's reagent (4 ppm FeSO 4 and 3% H 2 O 2 ). Moreover, the H 2 –O 2 fuel cell using Pip-PBI-C as membrane achieved a high open circuit voltage of 1.0 V and a peak power density of 785.6 mW cm −2 at the current density of 1802.9 mA cm −2 . ● A series of polybenzimidazoles containing alicyclic or aliphatic are prepared; ● Pip-PBIs with flexible chain segments have well solubility in low boiling point solvents namely methanol and isopropanol; ● The Pip-PBI-C shows the OH − conductivity of 108.8 mS cm −1 at 80 °C and excellent alkaline stability; ● The Pip-PBI-C shows the peak power density of 785.6 mW cm −2 at 1802.9 mA cm −2 in a H 2 –O 2 fuel cell.

“UV-curing of novel tri-functional melamine-phosphate oligomer: An effect of coating with polyurethane acrylate toward mechanical, thermal, and flame retardant properties”

A novel melamine-phosphate tri-functional acrylate (MPTO) was successfully synthesized via cyclization reaction of hexamethylolmelamine (HMM) with phosphorous oxychloride (POCl3) followed by addition reaction of hydroxyethylmethacrylate (HEMA). The molecular structure of MPTO was identified by FTIR and 1H-NMR, 13C-NMR, and GC-MS spectra. The synthesized MPTO oligomer was impregnated with polyurethane acrylate to make various formulations and UV cured on wood and galvanized steel panels. The results of UV cured films from differential scanning calorimeter (DSC) and thermo-gravimetric analysis (TGA) exhibited increase in thermal stability and highest char yield of 18.4% at 800°C. The diffused diffraction peak appearing around 2ϴ = 16–22° corresponds to an amorphous structure which leads to irregular arrangement with formation of strong cross-linking polymer network. Furthermore, all coating films show prominent flame retardancy with UL-94 V-0 rating and maximum limiting index (LOI) values of 34.8%. The polyurethane acrylate (PU) coatings cured with MPTO that exhibited excellent mechanical properties were estimated using various tests such as adhesion, pencil hardness, solvent resistance, flexibility, and corrosion test. The coating performance revealed that MPTO can improve the mechanical, thermal, and flame retardant properties because of its unique structure identity of melamine-phosphate moiety and long aliphatic segment of an acrylate ester.

Synthesis, Characterization and anti-corrosion property of GPTMS functionalized mesoporous silica (F-SBA-15) incorporated aliphatic chain containing polybenzoxazine nanocomposites

ABSTRACT The (F-SBA-15) dispersed aliphatic chain containing polybenzoxazine nanocomposite coating materials having better corrosion resistance property has been developed. The new aliphatic chain containing polybenzoxazines is synthesized from n-octylamine, bisphenol-A and paraformaldehyde involving mannich condensation reaction. The structure of polymer and monomer was examined with the help of proton magnetic resonance1NMR spectroscopy and Fourier transform IR spectroscopy. The polybenzoxazine composites were prepared n-octylamine, bisphenol-A and paraformaldehyde and using varying percentages (1, 5, 10 wt%) of GPTMS functionalized mesoporous silica (F-SBA-15) through in situ polymerization process. The polybenzoxazine nanocomposites were characterized using X-ray powder diffraction and scanning electron microscopy. In addition Surface treated (F-SBA-15) dispersed polybenzoxazine nanocomposites has been prepared and studied for their N2 adsorption/desorption, water contact angle, dielectric behavior and anticorrosive properties. The polymer nanocomposites subjected to the highest water contact angle noted at 115° was attained for 10 wt% (F-SBA-15). The value of dielectric constant for neat, 1, 5, 10 wt% (F-SBA-15) incorporated polymer nanocomposites was noted as 4.7, 3.8, 2.9, and 2.1, respectively. The corrosion resistant capacity of BZ/(F-SBA-15), on mild steel specimens, was noticeably higher than that of conventional polybenzoxazine due to the hydrophobic aliphatic chain segments and porous structure of (F-SBA-15).

Synthesis and properties of novel self-catalytic phthalonitrile monomers with aliphatic chain and their copolymerization with multi-functional fluorene-based benzoxazine monomers

A novel series of self-catalytic phthalonitrile monomers with aliphatic segments (BPAA) were synthesized via nitro nucleophilic substitution reaction of bisphenol compound and 4-nitrophthalonitrile. Bisphenol compound was reductant with secondary amine groups of Schiff base derived from the reaction of vanillin and one of the aliphatic diamine such as 1,2-ethylenediamine, 1,3-propane diamine, and 1,6-hexamethylenediamine. The curing reaction of BPAA monomers can be carried out without any catalyst. BPAA monomers showed excellent processing properties. Moreover, BPAA polymers (poly(BAPP)) showed superior thermal stabilities and higher glass-transition temperatures (Tg) (302–317 °C). The 5% thermal decomposition temperatures (T5) of poly(BAPP) and char yield (Yc) at 800 °C under nitrogen atmosphere were 352.5–410.5 °C and 61.3–66.8%, respectively. To further improve the thermal stability of poly(BAPP), BPAA monomers were modified by multi-functional fluorene-based benzoxazine monomers (MFFB) due to their excellent reaction activities. The results showed that BAPP/MFFB systems had high reaction activities and good processing behaviors. The similar thermal stabilities between BAPP and MFFB can give stable and excellent thermal stability (T5 ≥ 378 °C) to the poly(BAPP/MFFB) systems.

Flexible thin films based on poly(ester imide) materials for optoelectronic applications

AbstractA series of high‐performance poly(ester imide)s bearing cycloaliphatic moieties was manufactured by a two‐step procedure via solution polycondensation of an aromatic–aliphatic dianhydride containing preformed ester units and cyclohexanone ring in the main chain, with various aromatic diamines. The new dianhydride monomer, namely 2‐oxocyclohexane‐1,3‐bis[4,4′‐bis(trimellitate)benzylidene] dianhydride, was synthesized by the reaction between 2,6‐bis(4‐hydroxybenzylidene)cyclohexanone and trimellitic anhydride chloride. The chemical structure of the resulting dianhydride was confirmed by means of Fourier transform infrared, 1H NMR and 13C NMR spectroscopies. The poly(ester imide)s from the series exhibited water uptake capacity in the range 3.45–10.09%. The onset temperatures, corresponding to the first detected thermal weight loss in the samples, ranged from 367 to 441 °C. Besides the cycloaliphatic moieties coming from the dianhydride monomer, the other aliphatic segments present in the diamine structures were responsible for improved optical performance in the resulting poly(ester imide)s, the transmittance being higher than 80% at 684 nm. © 2021 Society of Industrial Chemistry.

Mesostructure of Composite Materials Based on Segmented Poly(Urethane Imide) Containing Ferrite Nanoparticles

The mesostructure of segmented poly(urethane imide) containing 4–10 wt % CoFe2O4 or Al3Fe5O12 nanoparticles was experimentally studied by small-angle polarized neutron scattering, which can analyze the nuclear and magnetic subsystems of the obtained composites. The transformation of the domain structure of the magnetic elastomers based on poly(urethane imide) was investigated at various concentrations, chemical compositions, and localizations of ferrite nanoparticles in polymer chains. The dynamics of the change in the segmental mobility of soft blocks during heating of samples was characterized by magnetic–nuclear interference scattering. The experiments detected changes in the supramolecular structure of the multiblock copolymer, which depended on the percentage and type of nanoparticles. The correlation radii were determined in the magnetic subsystem of ferrite nanoparticles embedded in hard aromatic blocks of poly(urethane imide) as nodes of intermolecular crosslinkers and chain extenders. The temperature dependence was analyzed for the intensity of small-angle nuclear scattering by poly(urethane imide) and magnetic elastomers based on it, under the conditions of the transition of soft aliphatic segments from the glassy to the highly elastic state.

Properties and DEFC tests of Nafion - Functionalized titanate nanotubes composite membranes prepared by melt-extrusion

Nafion based composites are promising materials to improve the performance of direct ethanol fuel cells. In this work, composite membranes of Nafion and titanate nanotubes functionalized with sulfonic acid groups were prepared by melt-extrusion and tested in a direct ethanol fuel cell. Far and mid infrared spectroscopies evidenced the formation of ionic bridges between the sulfonic acid groups of both functionalized nanoparticles and the ionomer. Small angle X-ray scattering measurements revealed that the melt-extrusion method leads to an uniform distribution of the inorganic phase in the ionomer matrix. Such structural analysis indicated that the improved the proton conduction properties of the composites, even with the addition of a high concentration of functionalized nanoparticles, are an outcome of the synergistic ionic network due to the hydrid organic/inorganic proton conducting phases. However, an improvement of the fuel cell performance is observed for 2.5 wt% of functionalized titanate nanotubes, which is a result of the lower ethanol crossover and the plasticizing effect of the aliphatic segments of the organic moieties grafted at the surface of the titanate nanoparticles.

Electrospinning in the preparation of an electrochemical sensor based on carbon nanotubes

This paper reports the development of an electrochemical sensor using electrospun polymeric fibers of PBAT (poly (butylene adipate co-terephthalate))/PLA (poly (lactic acid) containing functionalized carbon nanotubes (MWCNTs) and further calcined (at 500 °C under N2). The morphologies of the electrospun fibers were verified by SEM and those containing MWCNTs presented lower average diameter of 1.76 ± 0.30 μm against 3.67 ± 0.88 μm for the fibers of neat PBAT/PLA. Fourier transform infrared (FTIR) spectra of the polymeric fibers indicated possible interactions between the MWCNTs and the CO functional group. Thermogravimetric analysis (TGA) curves demonstrated slight increase of the stability of the PLA and lower thermal stability of the PBAT. Analyzes through differential scanning calorimetry (DSC) data showed that the interactions occur preferentially with the aliphatic segments of polymer chains; and corroborated the data from FTIR. Also, FTIR and X-ray powder diffraction (DRX) indicated, respectively, decrease on carboxylic groups amount and lamella formation on functionalized MWCNTs due to the PBAT/PLA/MWCNTs electrospun fibers calcination. The electrochemical measurements performed using sensor built based on the as-obtained calcined material showed that the sensor is promising for the determination of metronidazole in aqueous environment.

A theoretical study on the chirality detection of serine amino acid based on carbon nanotubes with and without Stone-Wales defects

In the present study, the interaction of serine (SER) amino acid (AA) with the pristine and defected carbon nanotubes (CNTs) has been investigated by employing the molecular dynamics (MD) and the density functional theory (DFT) approaches. Furthermore, the potential application of CNTs with and without the Stone-Wales (SW) defects in sensing of SER chirality has been studied. Our results confirm that introducing the chiral l and d SERs (LSER and DSER) exerts a significant effect on the electronic and optical properties of the CNTs with and without the SW defect. According to the MD results, it is observed that for all the structures, the obtained minimum distance is among the SER aliphatic segments and the tube atoms. The calculated structural and electronic properties of pristine and defected CNT are in good agreement with the reported research studies. The results indicate that pyramidalization angles (θp) at C atoms are altered in the presence of the SW defects. The overall increment of θp suggests that the reactivity has increased at the defective regions. In the case of CNT with one SW defect (CNTSW1), the central C–C bond of the SW defect is the most chemically reactive site. Our results establish that pristine CNT is a semiconductor when the LSER and DSER are adsorbed (with the band gap of 0.30 eV and 0.32 eV, respectively). The LSER-adsorbing CNT with two SW defects (CNTSW2) is a semiconductor with a reduced band gap (0.41 eV), while the DSER-adsorbing CNTSW2 is an n-type semiconductor (with a band gap of 0.70 eV). The optical properties are inferred from the dielectric functions of the CNTs. The most remarkable result belongs to the CNTSW2; the imaginary part of the CNTSW2 dielectric function can sensitively distinguish the chirality of the SER amino acid.

Organosulfides: An Emerging Class of Cathode Materials for Rechargeable Lithium Batteries.

Lithium-ion batteries have received significant attention over the last decades due to the wide application of portable electronics and increasing deployment of electric vehicles. In order to further increase the energy density of batteries and overcome the capacity limitations (<250 mAh g-1) of inorganic cathode materials, it is imperative to explore new cathode materials for rechargeable lithium batteries. Organic compounds including organic carbonyl, radicals, and organosulfides are promising as they have advantages of high capacities, abundant resources, and tunable structures. In the 1980s, a few organosulfides, in particular organodisulfides, as cathode materials were studied to a certain extent in rechargeable lithium batteries. However, they showed low capacities and poor cycling performance, which made them unappealing then in comparison to transition metal oxide cathode materials. As a result, organosulfides have not been extensively studied like other cathode materials including organic carbonyls and radicals. In recent years, organosulfides with long sulfur chains (e.g., trisulfide, tetrasulfide, pentasulfide, etc.) in the structures have been receiving more attention in conjunction with the development of lithium-sulfur batteries. As a major class of sulfur derivatives, they have versatile structures and unique properties in comparison with elemental sulfur. In this Account, we first generalize the working principles of organosulfides in lithium batteries. We then discuss organosulfide molecules, which have precise lithiation sites and tunable capacities. The organic functional groups can provide additional benefits, such as discharge voltage and energy efficiency enhancement by phenyl groups and cycling stability improvement by N-heterocycles. Furthermore, replacing sulfur by selenium in these compounds can improve their electrochemical properties due to the high electronic conductivity and low bond energy associated with selenium. We list organosulfide polymers consisting of phenyl rings, N-heterocycles, or aliphatic segments. Organosulfides as electrolyte additives or components for forming a solid-electrolyte interphase layer on lithium metal anode are also presented. Carbon materials such as carbon nanotubes and reduced graphene oxide can enhance the battery performance of organosulfide cathodes. We discuss the synthesis methods for polysulfide molecules and polymers. Finally, we show the advantages of organosulfides over sulfur as cathode materials in lithium batteries. This Account provides a summary of recent development, in-depth analysis of structure-performance relationship, and guidance for future development of organosulfides as promising cathode materials for next generation rechargeable lithium batteries.

Polyurethane Prepolymer Modified Cassava Starch Based Poly(butylene adipate‐co‐terephthalate) Composites with Excellent Compatibility and High Toughness

In this study, a high‐efficiency polyurethane prepolymer (PUP) compatibilizer is developed to improve the compatibility between cassava starch and poly(butylene adipate‐co‐terephthalate) with higher molecular weight (MPBAT). Preferentially, modified starch (MS) is prepared by reacting isocyanate groups of PUP with hydroxyl groups of starch in a high‐speed mixer, and then starch‐based MPBAT composites (MSPT) with PUP as a compatibilizer are continuously extruded using twin‐screw extruder. The mechanical properties, water absorption, and thermodynamic properties as well as morphology of MSPT are investigated with different PUP contents and at the same mass ratio of MPBAT to starch (1:1). Samples of MSPT‐2 provide satisfactory mechanical properties comparable to control samples. Addition of 13 wt.% PUP to MSPT, improves tensile strength from 3.8 to 11.9 MPa and increases elongation at break from 93.3 to 580.4% at room temperature compared with control without the PUP. The hydrophobicity and thermostability properties of MSPT‐2 composites are also enhanced. The results further prove that MSPT‐2 composites possess excellent compatibility, not only because of the urethane bonds of the PUP and starch, but also stemming from the physical crosslinking between soft segment of PUP and aliphatic segment of MPBAT. Starch‐based MPBAT composites with excellent compatibility and high toughness will help broaden the application field of biodegradable plastics.

5 V Stable Nitrile-Bearing Polymer Electrolyte with Aliphatic Segment as Internal Plasticizer

The electrochemical properties of polymer electrolytes based on poly(acrylonitrile-co-butadiene) and hydrogenated poly(acrylonitrile-co-butadiene) blended with lithium bis(trifluorosulfonyl)imide (LiTFSI) were characterized, showing that copolymerization of acrylonitrile with aliphatic comonomers is an effective means to develop conductive, yet oxidatively stable, polymer electrolytes. The copolymer compositions were both 40 wt % acrylonitrile, and the copolymer glass transition temperatures of NBR and HNBR were determined to be −17.7 and −24.3 °C, respectively. Differential scanning calorimetry (DSC) showed that the polymer electrolytes are amorphous when mixed with LiTFSI to a concentration of at least five nitrogen atoms for every one Li cation (N/Li = 5), and Fourier-transform infrared spectroscopy analysis of the nitrile stretch mode confirmed that the nitrile functional groups coordinate Li cations. At N/Li = 5, the ionic conductivity of HNBR:LiTFSI was determined to be 3.1 × 10–7 S/cm at 25 °C and ...