Polymer最新文献

{"title":"The importance of the modulation of the elastomer properties on the structure and performance of conjugated polymer/elastomer blends","authors":"Hongtao Shan,&nbsp;Jiaxin He,&nbsp;Xueting Cao,&nbsp;Yingying Yan,&nbsp;Jianjun Zhou,&nbsp;Hong Huo","doi":"10.1016/j.polymer.2025.128581","DOIUrl":"10.1016/j.polymer.2025.128581","url":null,"abstract":"<div><div>Physical blending with elastomers is a promising approach to improve the mechanical performance of conjugated polymers (CPs) without reducing their electrical performance, which is essential for stretchable flexible electronic devices. However, the effects of the properties of elastomers on the mechanical and electrical performance of CP/elastomer blend films remain unclear. Here, a stretchable semiconductor composite is systematically investigated, which is achieved by blending the brittle poly [4-(4,4-dihexadecyl-4H-cyclopenta [1,2-b:5,4-b′]dithiophen-2-yl)-alt-[1,2,5]thia-diazolo [3,4-c] pyridine] (PCDTPT) semiconductor with the thermosetting elastomer poly (dimethylsiloxane) (PDMS) containing different cross-linker contents. The cross-linker content affects the curing process of PDMS, thereby influencing the morphology and vertical phase separation structure of the PCDTPT/PDMS blend films and ultimately affecting their performance. By carefully modulating the properties of PDMS, a considerable phase separation structure, along with a network of small-sized nanofibers exhibiting long conjugation lengths or high backbone planarization, was obtained, resulting in blend films with electrical conductivity and crack onset strain (COS) values that are 2.7 times and 12.3 times greater than those of pure PCDTPT, respectively. Our findings demonstrate that precise control of cross-linker content serves as an effective strategy for modulating doping efficiency and achieving optimal performance of PCDTPT/PDMS blends. This work emphasizes the importance of the properties of elastomers on the performance of CP/elastomer blend films and provides valuable insights into appropriate elastomer selection for stretchable semiconducting thin films that simultaneously possess excellent mechanical and electrical properties.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128581"},"PeriodicalIF":4.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144122916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of epoxidation degree on strain-induced crystallization and mechanical properties of epoxidized natural rubber","authors":"Zixuan Wang ,&nbsp;Han Song ,&nbsp;Ruoyu Wang ,&nbsp;Xi Zhang ,&nbsp;Qipeng Yuan ,&nbsp;Yonglai Lu ,&nbsp;Weixiao Song ,&nbsp;Xiaohui Wu ,&nbsp;Guo-Hua Hu ,&nbsp;Liqun Zhang","doi":"10.1016/j.polymer.2025.128541","DOIUrl":"10.1016/j.polymer.2025.128541","url":null,"abstract":"<div><div>The epoxidation degree (ED) plays a critical role in shaping the microstructure and macroscopic performance of epoxidized natural rubber (ENR). Through the application of Synchrotron Radiation-Wide Angle X-ray Diffraction (SR-WAXD), polarized Fourier Transform Infrared (FTIR) spectroscopy, and Atomic Force Microscopy (AFM), the effects of different ED on the strain-induced crystallization (SIC) behavior, mechanical properties, and molecular chain orientation of ENRs were systematically investigated. The findings reveal that at a given strain there is an optimum ED with regard to crystallinity and mechanical performance. Notably, ENR10 (with an ED of 10 %) demonstrated the highest tensile strength of 30.8 MPa and tear strength of 35.9 kN/m, corresponding to improvements of 27.8 % and 40.2 %, respectively, compared to NR. The influence of the ED is most pronounced in the orientation and crystallite growth. For ENR with a low ED, epoxy groups enhance molecular chain orientation and SIC, facilitating the formation of more crystallites. The increased crystallite number allows for the rapid establishment of a crystallite network, promoting continuous crystallite growth and cross-linking. Consequently, significant increases in tensile and tear strength are observed. In contrast, ENR with a high ED reduced crystallite growth due to steric hindrance and increased interactions among the densely packed epoxy groups. This effect impairs crystallite formation and diminishes SIC capability, resulting in a notable decline in both crystallinity and mechanical properties.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"333 ","pages":"Article 128541"},"PeriodicalIF":4.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Self-healing and high mechanical strength epoxy anti-corrosion coatings based on dynamic disulfide bonds","authors":"Chunya Wang ,&nbsp;Mao Chen ,&nbsp;Kuibao Zhang ,&nbsp;Lin Zhou","doi":"10.1016/j.polymer.2025.128550","DOIUrl":"10.1016/j.polymer.2025.128550","url":null,"abstract":"<div><div>The waste of resources and safety hazards caused by metal corrosion have a significant impact on various industries. Epoxy resin coatings have become the most effective and commonly used means of corrosion protection due to their excellent adhesion and corrosion resistance to metallic materials. However, these coatings are inevitably damaged and cracked during use, which significantly reduces their corrosion resistance and service life. Herein, a novel composite coating with excellent self-healing and anti-corrosion properties was produced by a one-step spraying process. The prepared coatings have excellent mechanical properties like the polymers, with a tensile strength of 71.9 MPa. Meanwhile, due to abundant disulfide bonds inside the coating, scratch healing and electrochemical experiments have verified that these disulfide bonds will reconstruct the dynamic network as the temperature changes, thus realizing the coating's self-healing. In order to further improve the corrosion resistance of the coatings, two-dimensional nanofiller boron nitride (BNNS) was added. The electrochemical test (EIS) results showed that the coating containing 2 wt% BNNS nanofillers has good corrosion resistance, and the low-frequency impedance modulus of BNNS2/S–S EP coating is still higher than 10⁸ Ω cm² after 28 days immersion in 3.5 wt% NaCl solution. This study provides a new strategy for developing self-healing anticorrosive coatings with a synergistic combination of dynamic bonds and nanofillers.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128550"},"PeriodicalIF":4.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144104149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of entanglement concentration on the melt memory of polyethylene random copolymer","authors":"Zefan Wang ,&nbsp;Jiale Zeng ,&nbsp;Yuling Liang ,&nbsp;Rongchun Zhang ,&nbsp;Caizhen Zhu ,&nbsp;Jian Xu ,&nbsp;Alejandro J. Müller","doi":"10.1016/j.polymer.2025.128576","DOIUrl":"10.1016/j.polymer.2025.128576","url":null,"abstract":"<div><div>Upon heating a semi-crystalline polymer above its melting temperature, some ordered chain cluster structures inherited from previous crystallization processes can sometimes be preserved depending on the temperature. These structures can act as self-nuclei that enhance polymer nucleation during subsequent cooling. This phenomenon has been termed “melt memory”, and its nature has attracted much scientific discussion. Recent studies on poly(ε-caprolactone) and poly(ethylene oxide) in an extensive molecular weight range have demonstrated that increased entanglement density can strongly enhance the strength of melt memory. However, evidence for a quantitative relationship between entanglement concentration and melt memory temperature window is still scarce. In this work, we selected a narrowly distributed branched ethylene/butene-1 copolymer (i.e., hydrogenated polybutadiene) as a model material due to its wide melt memory temperature range caused by the segregation of crystallizable and non-crystallizable sequences. A series of PE blends with variable entanglement concentrations were prepared by mixing the ethylene/butene-1 copolymer with an unentangled low molecular weight linear polyethylene (PE). Differential scanning calorimetry (DSC) and small angle X-ray scattering (SAXS) results showed that lower entanglement concentration leads to thinner amorphous layers and, therefore, higher crystallinity. A quantitative relationship between entanglement concentration and melt memory effect has been established based on DSC self-nucleation experiments. Our results demonstrate that the dilution of entanglements and overall comonomer fractions reduces the complexity of the amorphous phase. As a result, nano-sized separated structures could be homogenized at lower temperatures, resulting in lower thermal stability of self-nuclei and, thus, weaker melt memory.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128576"},"PeriodicalIF":4.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zwitterionic, ion-in-conjugation porous polymer Networks: Synthesis and photooxidation of Bisphenol A in water","authors":"Aleksander Saša Markovič ,&nbsp;Tomaž Kotnik ,&nbsp;Sebastijan Kovačič","doi":"10.1016/j.polymer.2025.128574","DOIUrl":"10.1016/j.polymer.2025.128574","url":null,"abstract":"<div><div>In this work, we have developed an easy approach for vinylene-linked ion-in-conjugation porous polymer networks (IIC-PPN) using Knoevenagel polycondensation of predesigned zwitterionic <em>N</em>-(3-sulfopropyl)-2,6-(dimethyl)pyridinium salt and 1,3,5-triformylbenzene as monomers. The resulting IIC-PPNs exhibit a porous morphology with high specific surface areas up to 263 m² g⁻¹. Although the IIC-PPN network contains arylene-vinylene nodes that make it apolar, the incorporation of zwitterionic pyridinium building blocks enable a significant ionic dipole, which is reflected in the water uptake of 14.5 g g⁻¹, which is higher than that of similar poly (arylene-cyano-vinylene)s with 7.0, 8.5 and 5.3 g g⁻¹ for PAV<strong>–</strong>CN, PAV<strong>–</strong>OMe, and PAV<strong>–</strong>CHO, respectively. The IIC-PPNs exhibit significant semiconducting properties with optical absorption band edges of 512 nm and an electrochemical band gap of 2.55 eV. The intriguing properties of IIC-PPN prompted us to use them as heterogeneous photocatalysts to photooxidize the endocrine disrupting compound bisphenol A (BPA) dissolved in water under visible light.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128574"},"PeriodicalIF":4.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polymers and advanced characterization techniques for new societal demands at POLY-CHAR 2024","authors":"Araceli Flores ,&nbsp;Juan Francisco Vega (Guest Editors) ,&nbsp;Alejandro J. Müller (Editor)","doi":"10.1016/j.polymer.2025.128551","DOIUrl":"10.1016/j.polymer.2025.128551","url":null,"abstract":"","PeriodicalId":405,"journal":{"name":"Polymer","volume":"329 ","pages":"Article 128551"},"PeriodicalIF":4.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mussel-inspired 3,4-dihydroxybenzaldehyde-modified polyvinyl alcohol fibers with superior mechanical properties","authors":"Zheng Li ,&nbsp;Jie Li ,&nbsp;Jing Guo ,&nbsp;Fucheng Guan ,&nbsp;Xin Zhang ,&nbsp;Qiang Yang ,&nbsp;Da Bao ,&nbsp;Xinbin Ji ,&nbsp;Yihang Zhang ,&nbsp;Minghan Li ,&nbsp;Jiahao He ,&nbsp;Yi Xu","doi":"10.1016/j.polymer.2025.128544","DOIUrl":"10.1016/j.polymer.2025.128544","url":null,"abstract":"<div><div>Polyvinyl alcohol (PVA) fibers demonstrate considerable potential for application in industries such as manufacturing, medicine, construction, and daily life due to their unique physical and chemical properties. However, their mechanical properties and thermal stability still require further improvement. Inspired by the molecular structure of mussel foot proteins and their reinforcement mechanisms, we synthesized PVA grafted with various amounts of 3,4-dihydroxybenzaldehyde (DBA) via an aldol condensation reaction under acidic conditions. We then prepared a series of 3,4-dihydroxybenzaldehyde modified polyvinyl alcohol (DPVA) fibers using wet spinning technology. The results showed that the introduction of catechol groups disrupted the hydrogen bonding and crystallinity among PVA molecules, leading to a decrease in the viscosity of the spinning solution, fiber crystallinity, and the maximum thermal decomposition rate. However, during the formation of DPVA fibers, π-π interactions and an enhanced hydrogen bond network improved the tensile strength of the fibers, increasing it from 2.8 cN/dtex to 6.64 cN/dtex. Additionally, the cross-sectional morphology of the fibers changed from a kidney shape to a flat kidney shape, further indicating an improvement in their structural characteristics. This study's results provide novel insights into how the mechanical properties of PVA-based fibers can be optimized.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128544"},"PeriodicalIF":4.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"One-pot solvent-free recycling of mixed biodegradable plastics to useable polymers with trade-off mechanical properties","authors":"Zi-Xuan Luo,&nbsp;Guo-Qiang Tian,&nbsp;Si-Chong Chen,&nbsp;Gang Wu,&nbsp;Yu-Zhong Wang","doi":"10.1016/j.polymer.2025.128577","DOIUrl":"10.1016/j.polymer.2025.128577","url":null,"abstract":"<div><div>Biodegradable polyesters derived from cyclic monomers offer sustainable alternatives with closed-loop recyclability, yet practical implementation of conventional systems like polylactide (PLA) and poly(<em>ε</em>-caprolactone) (PCL) remains hindered by some challenges during depolymerization-repolymerization cycles. Herein, we present a solvent-free recycling strategy for mixed recyclable polyester plastics via catalytic alcoholysis and chain extension, yielding useable copolymer polyurethane (PLA/PCL-PU) with trade-off mechanical properties. Under a high-activity transesterification catalyst (i.e. tetrabutyl titanate), short-chain diol precursors (PLA/PCL-diol) were obtained from PLA and PCL mixtures and subsequently chain-extended with 1,6-diisocyanatehexane. The PLA/PCL-PU with a block copolymeric architecture characterized by diffusion-ordered spectroscopy and ¹³C nuclear magnetic resonance exhibits enhanced thermal stability and crystallinity of the PLA segments due to the incorporation of PCL segments. Significantly, the resultant PLA/PCL-PU copolymers deliver good comprehensive mechanical properties with a tensile strength of up to 51.0 ± 0.8 MPa and an elongation at break of maximum 379.4 ± 29.1 %. The recycled materials demonstrate packaging preservation ability and 3D printability, with an outstanding biocompatibility. PLA/PCL-PUs can be depolymerized into the corresponding re-polymerizable monomers, showing chemical recyclability. This one-pot solvent-free recycling approach circumvents traditional depolymerization bottlenecks, offering an eco-friendly and simplified route to convert mixed plastics into high-value materials.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128577"},"PeriodicalIF":4.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144113639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the brush structure of end-tethered poly(oligo(ethylene glycol) methyl ether methacrylate) chains","authors":"Iryna Romanenko,&nbsp;Radoslava Sivkova,&nbsp;Jan Svoboda,&nbsp;Tomáš Riedel,&nbsp;Andres de los Santos Pereira,&nbsp;Ognen Pop - Georgievski","doi":"10.1016/j.polymer.2025.128569","DOIUrl":"10.1016/j.polymer.2025.128569","url":null,"abstract":"<div><div>Polymer coatings of poly(oligo(ethylene glycol) methyl ether methacrylate) (poly(OEGMA)) have been often synthesized utilizing surface-initiated atom transfer radical polymerization (SI-ATRP) from halogen initiating moieties bound on the surface. This heterogeneous nonlinear analogue of polyethylene glycol has been widely used to introduce biocompatibility in various sensing, drug delivery, tissue engineering and microfluidics applications. While the chemical structure of the coating plays an important role in the biofunctionality, the physical conformational state of polymer chains determines the coating's properties. However, the actual state of the poly(OEGMA) polymer chains constituting the coatings has been rarely accessed. In this work, we have synthesized poly(OEGMA) polymer chains at various grafting densities by tuning the surface concentration of initiating groups in the range of 0.1–4.8 Br-atoms/nm². We thoroughly examined the chemical and physical structure of the poly(OEGMA) chains through various surface-sensitive techniques. To probe the viscoelastic response of the poly(MEOGMA) brushes of various grafting densities, we combined ex- and in-situ acoustic quartz crystal microbalance with dissipation monitoring (QCM-D) and variable angle spectroscopic ellipsometry (VASE) measurements. The detailed analysis in wet state points to similar relaxation times for the swollen poly(OEGMA) chains of various densities, i.e. similar stretched polymer brush chain conformation irrespectively of their density. The concomitant QCM-D-VASE analysis provided insights of the scaling behavior of the end-tethered poly(OEGMA) brushes with an exponent <em>n =</em> 0.54 throughout the whole studied density region, i.e. <em>σ</em> ranging from 0.04 to 0.27 chains/nm². The attained brush state of the polymer chains was further corroborated by the reduced grafting density parameter. The observed scaling behavior with an exponent specific to polymer brushes in the high-density region is governed by the strong perpendicular swelling of the chains from the tethering substrate, which is further assisted by the bulky MeOEG side chains, which sterically limit the coiling of the main polymer chain.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128569"},"PeriodicalIF":4.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144097285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel electrochromic polymers based on benzo[1,2-c:4,5-c']dithiophene-4,8-dione acceptor by varying different π-bridges and terminal active groups","authors":"Pengjie Chao ,&nbsp;Qicheng Su ,&nbsp;Yuqing Liao ,&nbsp;Daize Mo ,&nbsp;Lanqing Li ,&nbsp;Donghua Fan ,&nbsp;Yizhong Shi ,&nbsp;Dongling Shen","doi":"10.1016/j.polymer.2025.128557","DOIUrl":"10.1016/j.polymer.2025.128557","url":null,"abstract":"<div><div>In this work, we designed and synthesized a series of donor (D)-π-acceptor (A)- π-donor (D) type monomers, namely ETBD, EEBD, TTBD and TEBD, by varying the different π-bridges and terminal active groups in monomeric backbone based on the benzo [1,2-c:4,5-c']dithiophene-4,8-dione acceptor. And then their corresponding polymers PTEBD, PETBD, PEEBD and PTTBD were synthesized by electrochemical polymerization. EEBD exhibited the most red-shifted absorption peak at 487 nm and the lowest <em>E</em>_onset of 0.44 V among these monomers. Notably, in comparison with PTEBD, polymers PETBD, PEEBD and PTTBD achieved much higher optical contrast of 50.93 % at 830 nm, 39.94 % at 660 nm and 45.65 % at 1100 nm, respectively. In addition, PTTBD possessed the best electrochromic performance and displayed a color transition from dark purple in the neutral state to grey in the oxidation state with the best coloration efficiency (<em>CE</em>) value of 570.84 cm² C⁻¹ at 1100 nm among these polymers. These results demonstrated that the strategy of varying the different π-bridges and terminal active groups in polymer backbone based on the benzo [1,2-c:4,5-c']dithiophene-4,8-dione acceptor could improve the electrochromic performance, offering a promising approach to the design of high-performance electrochromic polymers.</div></div>","PeriodicalId":405,"journal":{"name":"Polymer","volume":"332 ","pages":"Article 128557"},"PeriodicalIF":4.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144097004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}