Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its...Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.展开更多
Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the...Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the direct incorporation of DMSO in polymer synthesis remains challenging.In this work,DMSO was successfully converted to nitrogen-containing heterocyclic polymers as a monomer via multicomponent polymerizations(MCPs)with dialdehydes and diamines in the presence of K_(2)S_(2)O_(8)/t-BuOK at 120℃in 6 h.A series of poly(phenylquinoline)s with high M_(w)values(up to 5.11×10^(4))were obtained in satisfactory yields(up to 82%),performing good solubility,good thermal and morphological stability as well as excellent film-forming ability.The thin films of poly(phenylquinoline)s exhibit high refractive index value in a wide wavelength range of 400–1700 nm.Thus,this work not only enriches the family of MCPs but also provides an efficient strategy for the conversion of DMSO into functional polymeric materials that are potentially applicable in diverse areas.展开更多
The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely investigated.However,the question of ...The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely investigated.However,the question of the“trade-off”between AEM ionic conductivity and dimensional stability remains difficult.The strategy of inducing microphase separation to improve the performance of AEM has attracted much attention recently,but the design of optimal molecular structures is still being explored.Here,this work introduced different ratios of 3-bromo-1,1,1-trifluoroacetone(x=40,50,and 60)into the main chain of poly(p-terphenylene isatin).Because fluorinated groups have excellent hydrophobicity,hydrophilic hydroxyl-containing side chains are introduced to jointly adjust the formation of phase separation structure.The results show that PTI-PTF_(50)-NOH AEM with the appropriate fluorinated group ratio has the best ionic conductivity and alkali stability under the combined effect of both.It has an ionic conductivity of 133.83 mS cm^(-1)at 80°C.In addition,the OH-conductivity remains at 89%of the initial value at 80°C and 3 M KOH for 1056 h of immersion.The cell polarization curve based on PTI-PTF_(50)-NOH shows a power density of 734.76 mW cm^(-2)at a current density of 1807.7 mA cm^(-2).展开更多
Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene...Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene-co-p-terphenyl piperidinium)(PPTP3F_(x)-DIL)AEMs with different fluorinated monomers for high performance AEMFCs.The polymerization of fluorinated monomers with other aryl monomers can effectively promote the separation of microphase in the membrane.It also has a high OH-conductivity at a low swelling.The membrane(PPTP3F_(4)-DIL)prepared by polycondensation of 2,2,2-trifluoro-1-(p-tolyl)ethan 1-one monomer achieves a high conductivity of 168.5 mS cm^(-1)at 80℃.At the same time,the water uptake is 40.0%and the swelling ratio is 12.1%.In addition,these membranes also have good mechanical properties and alkaline stability.After 1440 h of treatment in a NaOH(2 M)solution at 80℃,PPTP3F_(x)-DIL still maintains excellent tensile strength(>30.3 MPa)and elongation at break(>43.4%),and the conductivity retention of the PPTP3F_(1)-DIL membrane is 90.3%.The PPTP3F_(4)-DIL-based single cell exhibits a high peak power density(918.1 mW cm^(-2))and excellent durability(100 h)at 80℃.Therefore,these PPTP3F_(x)-DIL membranes have a wide range of applications in AEMFCs.展开更多
Poly(m-phenylene isophthalamide)(PMIA),a key aromatic polyamide,is widely used for its outstanding mechanical strength,high thermal stability,and excellent insulation properties.However,different applications demand v...Poly(m-phenylene isophthalamide)(PMIA),a key aromatic polyamide,is widely used for its outstanding mechanical strength,high thermal stability,and excellent insulation properties.However,different applications demand varying dielectric properties,so tailoring its dielectric per-formance is essential.PMIA was first synthesized in this study,followed by introducing pores and developing porous PMIA films and PMIA-based composites with reduced dielectric constants.Porous PMIA films were fabricated using the wet phase inversion process with N,N-dimethylac-etamide(DMAC)solvent and water as the non-solvent.The impact of casting solution composi-tion and coagulation bath temperature on pore structures was analyzed.A film produced with 18%PMIA and 5%LiCl in a 35℃coagulation bath achieved the lowest dielectric constant of 1.76 at 1 Hz,48%lower than the standard PMIA film,which had a tensile strength of 18.5 MPa and an initial degradation temperature of 320℃.展开更多
Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport ...Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1).展开更多
Smart pesticide delivery systems based on stimuli-responsive nanocarriers have attracted considerable attention because of their potential to enhance pesticide efficiency while reducing environmental risks.In this stu...Smart pesticide delivery systems based on stimuli-responsive nanocarriers have attracted considerable attention because of their potential to enhance pesticide efficiency while reducing environmental risks.In this study,a novel p H/glutathione dual-responsive pesticide delivery system was constructed through the synthesis of disulfide-bridged hollow mesoporous organosilica nanospheres(HMONs)via the St??ber method,followed by poly(acrylic acid)(PAA)coating through distillation-precipitation polymerization to form HMONs@PAA nanocomposites.The resulting abamectin-loaded system(Abamectin-HMONs@PAA)demonstrated a 12.73% pesticide loading capacity and significantly improved photostability,retaining twice as much active ingredient as free abamectin after 250 h of UV irradiation(36 W).Release studies revealed p H-and glutathione-dependent characteristics,with cumulative releases in acidic conditions exceeding those in neutral and alkaline environments by 18.66% and 40.98%,respectively,and a 14.2% increase in glutathione-containing solution(0.2 mmol·L^(-1) in 70% ethanol)after 97 h.Bioassays showed superior performance against Plutella xylostella,with a 13.33% reduction in survival rate compared to conventional suspension at equivalent dosage(40 mg·L^(-1)),while maintaining efficacy after extensive rainfall simulation(20 events over 10 days).This study provides a promising approach for developing environmentally responsive nanopesticides with enhanced durability and controlled-release properties,offering significant potential for sustainable crop protection.展开更多
Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardan...Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardant strategies often compromise their mechanical properties,hindering their practical applications.Herein,a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)-based comonomer(DDP)was used to synthesize flame-retardant poly(ethylene furandicarboxylate-co-phosphaphenanthrene)(PEFDn).The covalent integration of DDP confers intrinsic flame retardancy,avoiding the plasticization and migration issues associated with additive-type systems.Upon thermal decomposition,the DOPO-derived moieties release phosphoric acid and radical scavengers,promoting char formation and suppressing flame propagation.Furthermore,density functional theory(DFT)calculations combined with non-covalent interaction(NCI)analysis revealed that DOPO dimer molecules adopt a stable parallel-displaced π-π stacking configu ration,potentially facilitating microphase separation and enhancing the energy dissipation capability.PEFD_(10)achieves a UL-94 V-0 rating while simultaneously increasing impact toughness from 1.5 kJ/m^(2) to 14.7 kJ/m^(2).Im portantly,PEFDn maintained acceptable oxygen-barrier properties.PEFD10 also exhibited high transparency and UV-shielding performance.The combination of intrinsic flame safety,im pact-toughness resistance,UV shielding,and an oxygen barrier ensures reliable protection of electrical components and long-term operational stability.The integration of multiple critical properties within a single bio-based material represents a novel approach fo r enabling sustainable polymer solutions for high-pe rformance electrical applications.展开更多
Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves...Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves CS-based films by blending with poly(vinyl alcohol)(PVA)or glycerol(GLY)and using citric acid(CA)as a green,non-toxic cross-linker.Composite films were prepared by casting CS–PVA or CS-GLY with CA at 0%-0.20%(w/w of starch).The influence of CA on physicochemical,mechanical,optical,thermal,and water barrier properties was evaluated.CA crosslinking markedly enhanced the tensile strength,water resistance,and thermal stability of CS-PVA films while increasing transparency in CS–GLY films.At 0.20%CA,the composite achieved 34.99MPa tensile strength,reducedwater vapor permeability,andminimized water uptake.FTIR confirmed ester bond formation between CAand hydroxyl groups of CS,PVA,and GLY,whereas thermal analysis showed higher decomposition temperatures and lower weight loss in crosslinked films.Increasing CA levels also decreased opacity and improved light transmittance,indicating greater homogeneity and reduced crystallinity.This dual-polymer matrix combined with a natural crosslinking strategy provides a sustainable route to high-performance,biodegradable CS-based packaging materials.展开更多
Sulfate adsorption by poly（m-phenylenediamine）s（PmPDs） with various oxidation states synthesized through chemically oxidative polymerization was investigated.Series of sorption experiments were conducted,and the a...Sulfate adsorption by poly（m-phenylenediamine）s（PmPDs） with various oxidation states synthesized through chemically oxidative polymerization was investigated.Series of sorption experiments were conducted,and the adsorption mechanism and the relationship between oxidation state and adsorption performance were studied with the characterization of Fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）,pH tracking and energy calculation.The results show that the adsorption performance in acidic solution is improved with the decrease of oxidation state of poly（m-phenylenediamine）（PmPD）.The rate constant is as high as 425.5 mg/（g·min） in the short equilibrium time of 30 min.The estimated highest adsorptivity of sulfate ions is 95.1%.According to the Langmuir equation,the adsorbance is 108.5 mg/g.The sulfate desorption efficiency is about 95% and the accumulative adsorbance is up to 487.95 mg/g in 5 cycles.展开更多
Chemically oxidative polymerization of m-phenylenediamine was improved through adding the weak alkaline, Na2CO3. Results show that the poly （m-phenylenediamine） （PmPD） possesses a weak solubility in acidic solutio...Chemically oxidative polymerization of m-phenylenediamine was improved through adding the weak alkaline, Na2CO3. Results show that the poly （m-phenylenediamine） （PmPD） possesses a weak solubility in acidic solution according to total organic carbon （TOC） that the TOC is less than 8 mg/L, which is much lower than the discharge standard （20 mg/L）. The TOC of the PmPD synthesized with NaOH can be as high as 120.9 mg/L. This very weak solubility of PmPD synthesized with Na2CO3 facilitates its application in water purification. The oxidation state of PmPD is decreased and the yield is increased with a maximum of 84%, promoting the concentration of Na2CO3 in the synthesis. Moreover, the Cr（VI） performance of PmPD was marvelously enhanced with Na2CO3 to improve the synthesis. The largest Cr（VI） adsorbance can reach as high as 666.8 mg/g, which is far more than the performance of other common adsorbents.展开更多
Ladder-like polyphenylsilsesquioxanes with fairly high regularity were synthesized using an endo-template 1,2-ethylenediamine at mild temperature via direct co-hydrolysis and condensation reactions in the presence of ...Ladder-like polyphenylsilsesquioxanes with fairly high regularity were synthesized using an endo-template 1,2-ethylenediamine at mild temperature via direct co-hydrolysis and condensation reactions in the presence of acid catalysts in the mixture of 1,4-dioxane/H20. The features for synthesis of ladder-like polyphenylsilsesquioxanes were investigated in detail. The products obtained were characterized by FTIR, SEC, XRD and NMR.展开更多
The feasibility of employing nanofiltration for the removal of chromium（VI） from wastewater was investigated. Poly （m-phenylene isophthalamide） （PMIA） was used to fabricate asymmetric nanofiltration membrane thr...The feasibility of employing nanofiltration for the removal of chromium（VI） from wastewater was investigated. Poly （m-phenylene isophthalamide） （PMIA） was used to fabricate asymmetric nanofiltration membrane through the phase-inversion technique. Scanning electron microscopy （SEM） and atomic force microscopy （AFM） were used to characterize the obtained membrane, and the both confirmed a much smoother surface which could reduce membrane fouling. The PMIA membrane showed different rejections to electrolytes in a sequence of Na2SO4 〉 MgSO4 〉 NaC1 〉 MgC12, which was similar to the sequence of the negatively charged nanofiltration membranes. Separation experiments on chromium（VI） solution were conducted at various operating conditions, such as feed concentration, applied pressure and pH. It is concluded that chromium（VI） could be effectively removed from chromiumcontaining wastewater by the PMIA nanofiltration membranes while maintaining their pollution resistance under alkaline condition.展开更多
It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease of Molecular weight of the poly(2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) during the pol...It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease of Molecular weight of the poly(2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) during the polymerization, which ultimately led to inferior film qualities and device properties. The device (ITO/PEDOT/MEH-PPV/Ba/Al) with MEH-PPV prepared under dry conditions has an external quantum efficiency of above 2.0%.展开更多
Zinc phenylphosphonate （PPZn）, a benign and biocompatible nucleating agent, was prepared and incorporated into the biodegradable poly（ethylene adipate） （PEA） to investigate its effect on the crystallization beha...Zinc phenylphosphonate （PPZn）, a benign and biocompatible nucleating agent, was prepared and incorporated into the biodegradable poly（ethylene adipate） （PEA） to investigate its effect on the crystallization behavior, crystallization kinetics and spherulite morphology of PEA. Upon addition of PPZn, the crystallization temperature and crystallinity of PEA in the non-isothermal crystallization process increased significantly. Analysis of crystallization kinetics by Avrami equation suggests that the crystallization time shortened greatly and crystallization rate increased markedly after addition of PPZn. In the presence of PPZn, the spherulite size decreased and spherulite density increased significantly. It suggests that PPZn is an efficient nucleating agent for the crystallization of PEA. The accelerated crystallization in the presence of PPZn is mainly attributed to the epitaxial nucleation of PEA crystals on the surface of PPZn crystals, that is, a perfect lattice matching between PEA crystal and PPZn crystal occurs.展开更多
Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes(AEMs).Herein,a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with v...Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes(AEMs).Herein,a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with various amounts of electron-deficient 4,4′-dihydroxydiphenylsulfone and 4,4′-difluorobenzophenone to yield dense and selective reaction sites for chloromethylation and quaternization.As the most challenging step,chloromethylation was optimized by tuning the reaction temperature,reaction time,and reactant ratios.Ion exchange capacity,water uptake,anion conductivity,mechanical stability,and alkaline stability of the resulting AEMs were characterized in detail.It is found that chloromethylation reaction needed to be carried out at low equivalent of chloromethylation agents to avoid undesirable crosslinking.The QA-PAEKS-20 sample with an IEC of 1.19 mmol·g^-1 exhibited a Cl^–conductivity of 11.2 mS·cm^-1 and a water uptake of 30.2%at80°C,which are promising for AEM applications.展开更多
Poly（phenylene sulfide） （PPS） with different crosslinking levels was successfully fabricated by means of high- temperature isothermal treatment （IT）. The crosslinking degree of PPS was increased with IT time as ...Poly（phenylene sulfide） （PPS） with different crosslinking levels was successfully fabricated by means of high- temperature isothermal treatment （IT）. The crosslinking degree of PPS was increased with IT time as revealed by Fourier-transform infrared spectroscopy and dynamic viscosity measurements. Its influence on the non-isothermal crystallization behaviors of PPS was studied by differential scanning calorimeter （DSC）. The crystallization peak temperature of PPS with 6 h IT was 15 K higher than that of the one with 2 h IT at 30 K/min cooling rate. The non-isothermal crystallization data were also analyzed based on the Ozawa model. The Ozawa exponent m decreased from 3.5 to 2.2 at 232~C with the increase of the IT time, suggestive of intensive thermal oxidative crosslinking reducing the crystallite dimension as PPS crystal grew. The reduced cooling crystallization function K（T） was indicative of the larger activation energy of crosslinked PPS chain diffusion into crystal lattice, resulting in a slow crystal growth rate. Additionally, the overall crystallization rate of PPS was also accelerated with the increase of crosslinking degree from the observation of polarized optical micrograph. These results indicated that the chemical crosslinked points and network structures formed during the high-temperature isothermal treatment acted as the effective nucleating sites, which greatly promoted the crystallization process of PPS and changed the type of nucleation and the geometry of crystal growth accordingly.展开更多
A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were...A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were between 38,330 and 67,900. The glass transition temperatures （Tg） and 5% decomposition temperatures were ranged in 253-269 ℃ and 488-500 ℃, respectively, The structures of these copolymers were confirmed by FT-IR and ^1H NMR. Moreover, all the resultant copolymers were amorphous determined by wide angle X-ray diffraction （WAXD）.展开更多
While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are ca...While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).展开更多
A non-aqueous suspension polycondensation method was proposed to proceed the reaction ofp-phenylenediamine and terephthaloyl chloride for the preparation of poly（p-phenylene terephthalamide） （PPTA）. The system was...A non-aqueous suspension polycondensation method was proposed to proceed the reaction ofp-phenylenediamine and terephthaloyl chloride for the preparation of poly（p-phenylene terephthalamide） （PPTA）. The system was operated with NMP-CaCI2 solution as the dispersed phase and inert liquid paraffin as the continuous phase. Each of NMP-CaCl2 solution microdroplet suspended in paraffin served as a microreactor where the polycondensation took place. According to the results of TGA, XRD, IR, SEM and EA, PPTA with good quality was obtained through this novel method, and a number of main factors influencing this process were investigated to determine the optimum condition for the preparation of PPTA. Besides, this two-phase polycondensation system brings many unique advantages compared to the conventional solution polycondensation method, including a sealed reaction environment keeping the reactants away from oxygen and water, easy removal of HCI to promote the reaction, well-controlled temperature and low viscosity which means less energy cost.展开更多
基金the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2023C01072)the Institute of Zhejiang University-Quzhou for their financial support。
文摘Poly(phenylene oxide)(PPO)exhibits excellent dielectric properties,making it an ideal substrate for high-frequency,high-speed copper-clad laminates.The phenolic hydroxyl group at the end of PPO plays a key role in its reactivity.Accurately quantifying the phenolic hydroxyl content in PPO is essential but challenging.In this study,we proposed a method for measuring the phenolic hydroxyl content of PPO using differential UV absorption spectroscopy.In alkaline solutions,the phenolic hydroxyl in PPO completely ionizes to form phenoxide ions,leading to a significant increase in UV absorbance at approximately 250 and 300 nm.Notably,the differential UV absorbance at approximately 300 nm was directly proportional to the phenolic hydroxyl concentration.Using 2,6-dimethylphenol as a standard,a calibration curve was established to relate the phenolic hydroxyl concentration to differential UV absorbance at approximately 300 nm,providing a precise and straightforward method for phenolic hydroxyl quantification in PPO with distinct advantages over conventional techniques.
基金supported by the Scientific Research Start-up Fund Project of Anhui Polytechnic University for Introducing Talents(No.2022YQQ081)Natural Science Research Project of the Anhui Educational Committee(No.2024AH050133)the National Natural Science Foundation of China(No.22101088)。
文摘Dimethyl sulfoxide(DMSO)possessing strong solvency and high boiling point is a very important aprotic polar solvent in organic and polymer synthesis.Notably,it is also a useful synthon in organic chemistry.However,the direct incorporation of DMSO in polymer synthesis remains challenging.In this work,DMSO was successfully converted to nitrogen-containing heterocyclic polymers as a monomer via multicomponent polymerizations(MCPs)with dialdehydes and diamines in the presence of K_(2)S_(2)O_(8)/t-BuOK at 120℃in 6 h.A series of poly(phenylquinoline)s with high M_(w)values(up to 5.11×10^(4))were obtained in satisfactory yields(up to 82%),performing good solubility,good thermal and morphological stability as well as excellent film-forming ability.The thin films of poly(phenylquinoline)s exhibit high refractive index value in a wide wavelength range of 400–1700 nm.Thus,this work not only enriches the family of MCPs but also provides an efficient strategy for the conversion of DMSO into functional polymeric materials that are potentially applicable in diverse areas.
基金Natural Science Foundation of China(grant nos 22075031)Jilin Provincial Science&Technology Department(grant nos 20220201105GX)Jilin Provincial Development and Reform Commission(grant nos 2023C034-4)。
文摘The development of alkaline fuel cells is moving forward at an accelerated pace,and the application of ether-free bonded polymers to anion exchange membranes(AEMs)has been widely investigated.However,the question of the“trade-off”between AEM ionic conductivity and dimensional stability remains difficult.The strategy of inducing microphase separation to improve the performance of AEM has attracted much attention recently,but the design of optimal molecular structures is still being explored.Here,this work introduced different ratios of 3-bromo-1,1,1-trifluoroacetone(x=40,50,and 60)into the main chain of poly(p-terphenylene isatin).Because fluorinated groups have excellent hydrophobicity,hydrophilic hydroxyl-containing side chains are introduced to jointly adjust the formation of phase separation structure.The results show that PTI-PTF_(50)-NOH AEM with the appropriate fluorinated group ratio has the best ionic conductivity and alkali stability under the combined effect of both.It has an ionic conductivity of 133.83 mS cm^(-1)at 80°C.In addition,the OH-conductivity remains at 89%of the initial value at 80°C and 3 M KOH for 1056 h of immersion.The cell polarization curve based on PTI-PTF_(50)-NOH shows a power density of 734.76 mW cm^(-2)at a current density of 1807.7 mA cm^(-2).
基金support of the National Natural Science Foundation of China(Grant 22278340&22078272)。
文摘Improving the comprehensive performance of anion exchange membranes(AEMs)has a decisive impact on the wide application of anion exchange membrane fuel cells(AEMFCs).Herein,we prepared a series of new poly(phenanthrene-co-p-terphenyl piperidinium)(PPTP3F_(x)-DIL)AEMs with different fluorinated monomers for high performance AEMFCs.The polymerization of fluorinated monomers with other aryl monomers can effectively promote the separation of microphase in the membrane.It also has a high OH-conductivity at a low swelling.The membrane(PPTP3F_(4)-DIL)prepared by polycondensation of 2,2,2-trifluoro-1-(p-tolyl)ethan 1-one monomer achieves a high conductivity of 168.5 mS cm^(-1)at 80℃.At the same time,the water uptake is 40.0%and the swelling ratio is 12.1%.In addition,these membranes also have good mechanical properties and alkaline stability.After 1440 h of treatment in a NaOH(2 M)solution at 80℃,PPTP3F_(x)-DIL still maintains excellent tensile strength(>30.3 MPa)and elongation at break(>43.4%),and the conductivity retention of the PPTP3F_(1)-DIL membrane is 90.3%.The PPTP3F_(4)-DIL-based single cell exhibits a high peak power density(918.1 mW cm^(-2))and excellent durability(100 h)at 80℃.Therefore,these PPTP3F_(x)-DIL membranes have a wide range of applications in AEMFCs.
文摘Poly(m-phenylene isophthalamide)(PMIA),a key aromatic polyamide,is widely used for its outstanding mechanical strength,high thermal stability,and excellent insulation properties.However,different applications demand varying dielectric properties,so tailoring its dielectric per-formance is essential.PMIA was first synthesized in this study,followed by introducing pores and developing porous PMIA films and PMIA-based composites with reduced dielectric constants.Porous PMIA films were fabricated using the wet phase inversion process with N,N-dimethylac-etamide(DMAC)solvent and water as the non-solvent.The impact of casting solution composi-tion and coagulation bath temperature on pore structures was analyzed.A film produced with 18%PMIA and 5%LiCl in a 35℃coagulation bath achieved the lowest dielectric constant of 1.76 at 1 Hz,48%lower than the standard PMIA film,which had a tensile strength of 18.5 MPa and an initial degradation temperature of 320℃.
文摘Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1).
基金financially supported by the Jiangsu Forestry Science and Technology Innovation and Promotion Project(No.LYKJ-Nanjing[2022]02)the Jiangsu Agricultural Science and Technology Innovation Fund(No.CX(23)3090)。
文摘Smart pesticide delivery systems based on stimuli-responsive nanocarriers have attracted considerable attention because of their potential to enhance pesticide efficiency while reducing environmental risks.In this study,a novel p H/glutathione dual-responsive pesticide delivery system was constructed through the synthesis of disulfide-bridged hollow mesoporous organosilica nanospheres(HMONs)via the St??ber method,followed by poly(acrylic acid)(PAA)coating through distillation-precipitation polymerization to form HMONs@PAA nanocomposites.The resulting abamectin-loaded system(Abamectin-HMONs@PAA)demonstrated a 12.73% pesticide loading capacity and significantly improved photostability,retaining twice as much active ingredient as free abamectin after 250 h of UV irradiation(36 W).Release studies revealed p H-and glutathione-dependent characteristics,with cumulative releases in acidic conditions exceeding those in neutral and alkaline environments by 18.66% and 40.98%,respectively,and a 14.2% increase in glutathione-containing solution(0.2 mmol·L^(-1) in 70% ethanol)after 97 h.Bioassays showed superior performance against Plutella xylostella,with a 13.33% reduction in survival rate compared to conventional suspension at equivalent dosage(40 mg·L^(-1)),while maintaining efficacy after extensive rainfall simulation(20 events over 10 days).This study provides a promising approach for developing environmentally responsive nanopesticides with enhanced durability and controlled-release properties,offering significant potential for sustainable crop protection.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3700300)the National Natural Science Foundation of China(Nos.52573017 and U21B2093)+1 种基金Key Research and Development Program of Ningbo(No.2022Z200)the Zhejiang Provincial Natural Science Foundation(No.LY23E030005)。
文摘Bio-based 2,5-furandicarboxylic acid polyesters offer significant promise for reducing energy and environmental crises.However,their intrinsic flammability remains a critical limitation,and conventional flame-retardant strategies often compromise their mechanical properties,hindering their practical applications.Herein,a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)-based comonomer(DDP)was used to synthesize flame-retardant poly(ethylene furandicarboxylate-co-phosphaphenanthrene)(PEFDn).The covalent integration of DDP confers intrinsic flame retardancy,avoiding the plasticization and migration issues associated with additive-type systems.Upon thermal decomposition,the DOPO-derived moieties release phosphoric acid and radical scavengers,promoting char formation and suppressing flame propagation.Furthermore,density functional theory(DFT)calculations combined with non-covalent interaction(NCI)analysis revealed that DOPO dimer molecules adopt a stable parallel-displaced π-π stacking configu ration,potentially facilitating microphase separation and enhancing the energy dissipation capability.PEFD_(10)achieves a UL-94 V-0 rating while simultaneously increasing impact toughness from 1.5 kJ/m^(2) to 14.7 kJ/m^(2).Im portantly,PEFDn maintained acceptable oxygen-barrier properties.PEFD10 also exhibited high transparency and UV-shielding performance.The combination of intrinsic flame safety,im pact-toughness resistance,UV shielding,and an oxygen barrier ensures reliable protection of electrical components and long-term operational stability.The integration of multiple critical properties within a single bio-based material represents a novel approach fo r enabling sustainable polymer solutions for high-pe rformance electrical applications.
基金supported through RIIM Competition funding from the Indonesia Endowment Fund for Education Agency,Ministry of Finance of the Republic of Indonesia and National Research and Innovation Agency of Indonesia according to the contract number:61/IV/KS/5/2023 and 2131/UN6.3.1/PT.00/2023.
文摘Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves CS-based films by blending with poly(vinyl alcohol)(PVA)or glycerol(GLY)and using citric acid(CA)as a green,non-toxic cross-linker.Composite films were prepared by casting CS–PVA or CS-GLY with CA at 0%-0.20%(w/w of starch).The influence of CA on physicochemical,mechanical,optical,thermal,and water barrier properties was evaluated.CA crosslinking markedly enhanced the tensile strength,water resistance,and thermal stability of CS-PVA films while increasing transparency in CS–GLY films.At 0.20%CA,the composite achieved 34.99MPa tensile strength,reducedwater vapor permeability,andminimized water uptake.FTIR confirmed ester bond formation between CAand hydroxyl groups of CS,PVA,and GLY,whereas thermal analysis showed higher decomposition temperatures and lower weight loss in crosslinked films.Increasing CA levels also decreased opacity and improved light transmittance,indicating greater homogeneity and reduced crystallinity.This dual-polymer matrix combined with a natural crosslinking strategy provides a sustainable route to high-performance,biodegradable CS-based packaging materials.
基金Project(50925417) supported by China National Funds for Distinguished Young ScientistsProject(50830301) supported by the National Natural Science Foundation of China+1 种基金Project(2009ZX07212-001-01) supported by Major Science and Technology Program for Water Pollution Control and Treatment of ChinaProject(2011) supported by Hunan Nonferrous Fundamental Research Fund
文摘Sulfate adsorption by poly（m-phenylenediamine）s（PmPDs） with various oxidation states synthesized through chemically oxidative polymerization was investigated.Series of sorption experiments were conducted,and the adsorption mechanism and the relationship between oxidation state and adsorption performance were studied with the characterization of Fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）,pH tracking and energy calculation.The results show that the adsorption performance in acidic solution is improved with the decrease of oxidation state of poly（m-phenylenediamine）（PmPD）.The rate constant is as high as 425.5 mg/（g·min） in the short equilibrium time of 30 min.The estimated highest adsorptivity of sulfate ions is 95.1%.According to the Langmuir equation,the adsorbance is 108.5 mg/g.The sulfate desorption efficiency is about 95% and the accumulative adsorbance is up to 487.95 mg/g in 5 cycles.
基金Project(2011467062)supported by National Public Welfare Research Project of Environmental Protection Industry,ChinaProject(50925417)supported by National Science Fund for Distinguished Young Scholars of ChinaProject(50830301)supported by the National Natural Science Foundation of China
文摘Chemically oxidative polymerization of m-phenylenediamine was improved through adding the weak alkaline, Na2CO3. Results show that the poly （m-phenylenediamine） （PmPD） possesses a weak solubility in acidic solution according to total organic carbon （TOC） that the TOC is less than 8 mg/L, which is much lower than the discharge standard （20 mg/L）. The TOC of the PmPD synthesized with NaOH can be as high as 120.9 mg/L. This very weak solubility of PmPD synthesized with Na2CO3 facilitates its application in water purification. The oxidation state of PmPD is decreased and the yield is increased with a maximum of 84%, promoting the concentration of Na2CO3 in the synthesis. Moreover, the Cr（VI） performance of PmPD was marvelously enhanced with Na2CO3 to improve the synthesis. The largest Cr（VI） adsorbance can reach as high as 666.8 mg/g, which is far more than the performance of other common adsorbents.
基金financially supported by the Zhejiang Provincial Natural Science Foundation(No.LY14E030008)the Commonweal Technology Application Research Project of Zhejiang Province(No.2013C31079)+1 种基金the National Natural Science Foundation of China(No.51353003)the China Postdoctoral Science Foundation(No.2013 M531455)
文摘Ladder-like polyphenylsilsesquioxanes with fairly high regularity were synthesized using an endo-template 1,2-ethylenediamine at mild temperature via direct co-hydrolysis and condensation reactions in the presence of acid catalysts in the mixture of 1,4-dioxane/H20. The features for synthesis of ladder-like polyphenylsilsesquioxanes were investigated in detail. The products obtained were characterized by FTIR, SEC, XRD and NMR.
基金supported by the High Technology Research and Development Program (863) of China(No. 2007AA06Z339)the National Key Technologies R&D Program of China (No. 2006BAD01B02-02,2006BAJ08B00)
文摘The feasibility of employing nanofiltration for the removal of chromium（VI） from wastewater was investigated. Poly （m-phenylene isophthalamide） （PMIA） was used to fabricate asymmetric nanofiltration membrane through the phase-inversion technique. Scanning electron microscopy （SEM） and atomic force microscopy （AFM） were used to characterize the obtained membrane, and the both confirmed a much smoother surface which could reduce membrane fouling. The PMIA membrane showed different rejections to electrolytes in a sequence of Na2SO4 〉 MgSO4 〉 NaC1 〉 MgC12, which was similar to the sequence of the negatively charged nanofiltration membranes. Separation experiments on chromium（VI） solution were conducted at various operating conditions, such as feed concentration, applied pressure and pH. It is concluded that chromium（VI） could be effectively removed from chromiumcontaining wastewater by the PMIA nanofiltration membranes while maintaining their pollution resistance under alkaline condition.
基金This work were supported by the National Natural Science Foundation of China (Project No29992530-6) and the Natural Science Foundation of Guangdong Province (Grant No. 990623).
文摘It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease of Molecular weight of the poly(2-methoxy,5-(2'-ethylhexyloxy)-1,4-phenylene vinylene) during the polymerization, which ultimately led to inferior film qualities and device properties. The device (ITO/PEDOT/MEH-PPV/Ba/Al) with MEH-PPV prepared under dry conditions has an external quantum efficiency of above 2.0%.
基金financially supported by the National Natural Science Foundation of China(No.21304070)Natural Science Foundation of Tianjin City(No.15JCYBJC47300)+1 种基金Major Program of National Natural Science Foundation of China(No.11432016)the Municipal Key Program of Natural Science Foundation of Tianjin(No.14JCZDJC40700)
文摘Zinc phenylphosphonate （PPZn）, a benign and biocompatible nucleating agent, was prepared and incorporated into the biodegradable poly（ethylene adipate） （PEA） to investigate its effect on the crystallization behavior, crystallization kinetics and spherulite morphology of PEA. Upon addition of PPZn, the crystallization temperature and crystallinity of PEA in the non-isothermal crystallization process increased significantly. Analysis of crystallization kinetics by Avrami equation suggests that the crystallization time shortened greatly and crystallization rate increased markedly after addition of PPZn. In the presence of PPZn, the spherulite size decreased and spherulite density increased significantly. It suggests that PPZn is an efficient nucleating agent for the crystallization of PEA. The accelerated crystallization in the presence of PPZn is mainly attributed to the epitaxial nucleation of PEA crystals on the surface of PPZn crystals, that is, a perfect lattice matching between PEA crystal and PPZn crystal occurs.
基金financially supported by the National Natural Science Foundation of China (Nos. 51873037 and 51503038)
文摘Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes(AEMs).Herein,a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with various amounts of electron-deficient 4,4′-dihydroxydiphenylsulfone and 4,4′-difluorobenzophenone to yield dense and selective reaction sites for chloromethylation and quaternization.As the most challenging step,chloromethylation was optimized by tuning the reaction temperature,reaction time,and reactant ratios.Ion exchange capacity,water uptake,anion conductivity,mechanical stability,and alkaline stability of the resulting AEMs were characterized in detail.It is found that chloromethylation reaction needed to be carried out at low equivalent of chloromethylation agents to avoid undesirable crosslinking.The QA-PAEKS-20 sample with an IEC of 1.19 mmol·g^-1 exhibited a Cl^–conductivity of 11.2 mS·cm^-1 and a water uptake of 30.2%at80°C,which are promising for AEM applications.
基金financially supported by the National Science Fund for Distinguished Young Scholars (No.50925311)the National Natural Science Foundation of China (No.20976112)
文摘Poly（phenylene sulfide） （PPS） with different crosslinking levels was successfully fabricated by means of high- temperature isothermal treatment （IT）. The crosslinking degree of PPS was increased with IT time as revealed by Fourier-transform infrared spectroscopy and dynamic viscosity measurements. Its influence on the non-isothermal crystallization behaviors of PPS was studied by differential scanning calorimeter （DSC）. The crystallization peak temperature of PPS with 6 h IT was 15 K higher than that of the one with 2 h IT at 30 K/min cooling rate. The non-isothermal crystallization data were also analyzed based on the Ozawa model. The Ozawa exponent m decreased from 3.5 to 2.2 at 232~C with the increase of the IT time, suggestive of intensive thermal oxidative crosslinking reducing the crystallite dimension as PPS crystal grew. The reduced cooling crystallization function K（T） was indicative of the larger activation energy of crosslinked PPS chain diffusion into crystal lattice, resulting in a slow crystal growth rate. Additionally, the overall crystallization rate of PPS was also accelerated with the increase of crosslinking degree from the observation of polarized optical micrograph. These results indicated that the chemical crosslinked points and network structures formed during the high-temperature isothermal treatment acted as the effective nucleating sites, which greatly promoted the crystallization process of PPS and changed the type of nucleation and the geometry of crystal growth accordingly.
文摘A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were between 38,330 and 67,900. The glass transition temperatures （Tg） and 5% decomposition temperatures were ranged in 253-269 ℃ and 488-500 ℃, respectively, The structures of these copolymers were confirmed by FT-IR and ^1H NMR. Moreover, all the resultant copolymers were amorphous determined by wide angle X-ray diffraction （WAXD）.
基金This work was in part supported by the Hong Kong Research Grants Council(HKUST6062/98P and DAG96/97 SC11).
文摘While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60).
基金financially supported by the National Natural Science Foundation of China(Nos.U1463208 and 91334201)
文摘A non-aqueous suspension polycondensation method was proposed to proceed the reaction ofp-phenylenediamine and terephthaloyl chloride for the preparation of poly（p-phenylene terephthalamide） （PPTA）. The system was operated with NMP-CaCI2 solution as the dispersed phase and inert liquid paraffin as the continuous phase. Each of NMP-CaCl2 solution microdroplet suspended in paraffin served as a microreactor where the polycondensation took place. According to the results of TGA, XRD, IR, SEM and EA, PPTA with good quality was obtained through this novel method, and a number of main factors influencing this process were investigated to determine the optimum condition for the preparation of PPTA. Besides, this two-phase polycondensation system brings many unique advantages compared to the conventional solution polycondensation method, including a sealed reaction environment keeping the reactants away from oxygen and water, easy removal of HCI to promote the reaction, well-controlled temperature and low viscosity which means less energy cost.
