Reactive & Functional Polymers最新文献

{"title":"OG-POSS synergistically enhances the corrosion resistance and adhesion property of primer for silicone resin thermal protective coating","authors":"Ting Pan ,&nbsp;Hao Wu ,&nbsp;Zhiqiang Guan ,&nbsp;Xiaofei Zhu ,&nbsp;Yingqian Hu ,&nbsp;Linxuan Fang ,&nbsp;Yongbing Pei ,&nbsp;Lianbin Wu","doi":"10.1016/j.reactfunctpolym.2024.106066","DOIUrl":"10.1016/j.reactfunctpolym.2024.106066","url":null,"abstract":"<div><div>Octaglycidyldimethylsilyl polyhydric silsesquioxane (OG-POSS) in coordination with tetraethyl orthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate mixed solution was applied to the bonding of metal substrate and silicone resin thermal protective coating. The influence of OG-POSS addition on the interface of primer was systematically investigated by means of scanning electron microscope (SEM), salt spray test, thermogravimetric infrared spectroscopy (TGA-IR) and back temperature test. Results showed that the addition of OG-POSS favored the formation of a silane film of the primer, resulting in a more compact and continuous film. At the same time, the silane film had excellent corrosion resistance and adhesion, with a maximum adhesion strength of about 1.42 MPa. In addition, OG-POSS provided a unique Si-O-Si cage structure in the primer, which improved the ablation resistance of the interface layer, preventing the degradation and peeling of the coating in harsh environments.</div></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106066"},"PeriodicalIF":4.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation and performance study of thermo-responsive P(NIPAM-AM-ABP)/keratin composite nanofiber membrane for bio-application","authors":"Yaya Feng ,&nbsp;Tongda Lei ,&nbsp;Shiyang Chen ,&nbsp;Mengli Jin ,&nbsp;Qian Zhang ,&nbsp;Fenge Li ,&nbsp;Xipeng Li ,&nbsp;Jie Fan","doi":"10.1016/j.reactfunctpolym.2024.106065","DOIUrl":"10.1016/j.reactfunctpolym.2024.106065","url":null,"abstract":"<div><div>This paper describes a temperature-responsive composite nanofibrous membrane by blending of the P(NIPAM-AM-ABP) (PNAA) nanofiber and the wool keratin (WK) nanofiber. The photo crosslinkable PNAA with the LCST value of 38.1 °C was obtained by free radical copolymerization of the temperature sensitive N-Isopropylacrylamide (NIPAM) monomer, the hydrophilic monomer Acrylamide (AM), and the photo crosslinkable monomer 4-Acryloyloxybenzophenone (ABP). Keratin was extracted from waste wool fiber by reduction method. The PNAA nanofiber (PNAA-NF) and the keratin nanofiber (WK-NF) were electoral spun separately by two-needle parallel spinning, and the obtained composite nanofiber membrane was then crosslinked by UV irradiation and heat treatments to prepare the PNAA/WK nanofiber membrane (PNAA/WK-NFM) with good water tolerance. The result indicated that the photo cross-linkable temperature sensitive PNAA with the LCST of 38.1 °C was successfully synthesized. The obtained PNAA/WK-NFM has a good fibrous morphology and excellent water tolerance. The composite nanofiber membrane showed good reversible temperature sensitivity and temperature responsive drug releasing property due to the PNAA. By combining of the PNAA-NF and WK-NF, the mechanical property of the PNAA/WK-NFM was greatly enhanced in both dry and wet states, and the slow drug releasing property of the membrane was further improved. In-vitro cell culture experiments indicated that the PNAA/WK-NFM has a good biocompatibility with no cytotoxicity. These findings suggested that the PNAA/WK-NFM has a potential application in temperature responsive drug releasing biomaterials.</div></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106065"},"PeriodicalIF":4.5,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“Click”able monomer and polymers based on Azide-functionalized 3,4-Propylenedioxythiophene with tunable processibility","authors":"Junmo Kang ,&nbsp;Kyukwan Zong ,&nbsp;Youn-Sik Lee","doi":"10.1016/j.reactfunctpolym.2024.106063","DOIUrl":"10.1016/j.reactfunctpolym.2024.106063","url":null,"abstract":"<div><div>This research introduces 3,3-bis(azidomethyl)-3,4-dihydro-2<em>H</em>-thieno[3,4-<em>b</em>][1,4]dioxepine (ProDOT-AM2) as a versatile building block monomer for the synthesis of variously functionalized monomers and copolymers via “click”able 1,3-dipolar cycloaddition. The efficiency of this building block as a precursor to a wide range of ProDOT-based monomers is demonstrated by click reaction with various alkynes. The 1,3-dipolar cycloaddition of ProDOT-AM2 with different alkynes in the presence of a catalyst yields a novel class of ProDOT derivatives via a “triazole-locker” mechanism. Depending on the bases utilized, two distinct types of functionalized monomers, namely bistriazole and triazole, are obtained. The resulting polymers from the oxidative polymerization of selected monomers exhibit high solution processability and stability under multiple chemical redox processes, demonstrating potential applications in chemical chromics. Additionally, a conjugated copolymer containing ProDOT-AM2 is synthesized via Stille reaction conditions and subsequently post-functionalized with alkynes via a “triazole-locker” mechanism. Characterization studies via IR and ¹H NMR confirm the successful post-functionalization of the polymer. Electropolymerization of ProDOT-AM2 yields an electroactive polymer (PProDOT-AM2), indicating its potential utility in conducting polymers to be further post-functionalized. Overall, this methodology presents a straightforward approach for synthesizing a new class of monomers for conducting polymers and polymer modification using click chemistry.</div></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106063"},"PeriodicalIF":4.5,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and chemical recycling investigations of polythioureas","authors":"Rafael N.L. de Menezes ,&nbsp;Olga Gordivska ,&nbsp;Tran Tam Nguyen ,&nbsp;Niklas Warlin ,&nbsp;Nicola Rehnberg ,&nbsp;Baozhong Zhang","doi":"10.1016/j.reactfunctpolym.2024.106062","DOIUrl":"10.1016/j.reactfunctpolym.2024.106062","url":null,"abstract":"<div><div>There is currently intensive research on the development of biobased polymers as potential alternatives to the environmentally hazardous isocyanate-based polyurethanes. In this context, polythioureas (PTUs) form a particularly attractive target because they can be synthesized by using isothiocyanates, a class of molecules that can be found in nature with expected low toxicity. Herein, a series of 16 PTUs with varied chemical structures, mostly being new polymers, have been synthesized and their possible chemical recycling pathways via thermally induced and acid-catalyzed depolymerizations have been investigated. The obtained PTUs showed a varied range of molecular weights (up to M_n ∼ 69.5 kDa), intrinsic viscosity (up to ∼6 dL/g), and glass transition temperatures (T_g ∼ 59–128 °C). Notably, we observed that the presence of aromatic segments lowered the thermal stability of the polymers, so they were generally easier to depolymerize (compared to those without aromatic groups), forming oligomers with controlled end-groups (i.e. telechelic polymers) that could be repolymerized. The obtained aliphatic PTUs were generally resistant against thermochemical depolymerizations, but they could be effectively depolymerized by sulfuric acid. The repolymerization methods depended on the end groups of the depolymerized products, which in this work included direct repolymerization of polythioureas (if the end groups contain ∼1:1 of isothiocyanates and amines) and copolymerizations with another monomer terephthaldehyde (if the end groups contain only amines). Our results provided a first comprehensive molecular insight into the synthetic and recycling possibilities of using isothiocyanates and polythioureas in the exploration of potential alternatives for isocyanates and polyurethanes.</div></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106062"},"PeriodicalIF":4.5,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rh nanoparticles confined in triphenylphosphine oxide-functionalized core-crosslinked micelles with a polyanionic shell: Synthesis, characterization, and application in aqueous biphasic hydrogenation","authors":"Chantal J. Abou-Fayssal ,&nbsp;Leonhard Schill ,&nbsp;Rinaldo Poli ,&nbsp;Anders Riisager ,&nbsp;Eric Manoury ,&nbsp;Karine Philippot","doi":"10.1016/j.reactfunctpolym.2024.106061","DOIUrl":"10.1016/j.reactfunctpolym.2024.106061","url":null,"abstract":"<div><div>Core-crosslinked micelles (CCMs) with a hydrophilic polyanionic shell made of poly(sodium styrene sulfonate) chains, P(SS⁻Na⁺), a triphenylphosphine oxide-functionalized polystyrene core (TPPO@PSt) and crosslinked at the inner end of the polystyrene chains by diethylene glycol dimethacrylate (DEGDMA) were synthesized by reversible addition-fragmentation chain-transfer (RAFT) polymerization as a stable TPPO@CCM-A latex. One-pot synthesis of rhodium nanoparticles (RhNPs) by the reduction of [Rh(COD)(<em>μ</em>-Cl)]₂ in the aqueous TPPO@CCM-A latex yielded a stable RhNP-TPPO@CCM-A latex without the need of additional stabilizer or base. This Rh-loaded latex was applied to the catalytic biphasic hydrogenation of styrene under mild conditions with complete selectivity towards ethylbenzene and corrected turnover frequencies (<em>c</em>TOFs) ranging from 3250 to 10,010 h⁻¹ based on the surface atoms of the RhNPs. Importantly, the catalytic phase proved recyclable after product extraction, owing to the efficient retention of the RhNPs by the core TPPO ligands.</div></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106061"},"PeriodicalIF":4.5,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retraction notice to “KCl nanoparticles-loaded octaphenylsilsesquioxane as an efficient flame retardant for polycarbonate” [Reactive and Functional Polymers 177 (2022) 105284]","authors":"Xiaolu Wu,&nbsp;Zhaolu Qin,&nbsp;Wenchao Zhang,&nbsp;Rongjie Yang","doi":"10.1016/j.reactfunctpolym.2024.106060","DOIUrl":"10.1016/j.reactfunctpolym.2024.106060","url":null,"abstract":"","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"204 ","pages":"Article 106060"},"PeriodicalIF":4.5,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoactive fluorenyl-functionalized polypropylene for high-performance dielectrics","authors":"Angélica Martín-Lorenzo,&nbsp;Enrique Blázquez-Blázquez,&nbsp;José Manuel Gómez-Elvira,&nbsp;Mario Hoyos-Núñez","doi":"10.1016/j.reactfunctpolym.2024.106059","DOIUrl":"10.1016/j.reactfunctpolym.2024.106059","url":null,"abstract":"<div><p>Reducing the impact of polyolefins on the environment is a difficult task not only because of its ubiquity in everyday items, but also because these polymers are used on a massive scale as high-performance materials, for example in electronics and automotive applications. This is the case for polypropylene that behaves as a robust and efficient dielectric in capacitors as a result of its high melting temperature and very low dielectric dissipation factor. The current challenge is to increase its low permittivity, in order to improve energy density and, at the same time, to contribute to the reduction of production, thus progressively increasing the miniaturization of devices.</p><p>Low content functionalisation has been found to be an efficient route to rise the polypropylene (PP) permittivity, without compromising the mechanical and thermal stability of the material. Recent work has shown that decreasing chain mobility in the amorphous phase is key to maintaining dielectric loss into the low level of PP. This has been achieved by inserting carbazole or N-alkyl pyrrole groups. The former increases the T_g due to their characteristic π-π stacking interactions and both enable tailored crosslinking, UV and thermally activated respectively.</p><p>The present study analyses the synthesis and thermal and dielectric stabilities of poly-(propylene-<em>co</em>-9-(undec-10-en-1-yl)-9<em>H</em>-fluorene), with fluorene contents up to 3 mol%, as another example of PP grade that has both enhanced T_g and crosslinking potential under UV radiation. Initial results reveal that these materials have a relative permittivity (ɛ_r) up to 3 and dielectric losses under 0.005. As in the case of carbazole, the strong π-π stacking between fluorene units improves the thermal, mechanical and dielectric responses and also, that further improvement in stability would be possible under appropriate post-processing irradiation conditions.</p></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106059"},"PeriodicalIF":4.5,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1381514824002347/pdfft?md5=4ebd53de6e578a43d49ddeb9a8186238&pid=1-s2.0-S1381514824002347-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tough, high-strength, flame-retardant and recyclable polyurethane elastomers based on dynamic borate acid esters","authors":"Tiantian Zhang ,&nbsp;Siqi Huo ,&nbsp;Guofeng Ye ,&nbsp;Cheng Wang ,&nbsp;Qi Zhang ,&nbsp;Zhitian Liu","doi":"10.1016/j.reactfunctpolym.2024.106056","DOIUrl":"10.1016/j.reactfunctpolym.2024.106056","url":null,"abstract":"<div><div>With the wide application of polyurethane elastomers, it is necessary to develop recyclable, fire-retardant polyurethane elastomers with great mechanical properties to comply with industrial requirements. Herein, we fabricated a flame-retardant, recyclable, strong yet tough polyurethane elastomer (PIDB-1) based on dynamic borate acid esters. The introduction of phosphaphenanthrene and boron-containing groups endow PIDB-1 with great flame retardancy, as reflected by it achieving the vertical burning (UL-94) <em>V</em>-0 rating. The PIDB-1 film shows high visible light transmittance, and its transmittance reaches 90 % at the wavelength of 800 to 900 nm. The tensile strength of PIDB-1 is 54.9 MPa, and its toughness reaches 207.8 kJ/m³, indicative of superior mechanical properties. Meanwhile, the dynamic borate acid esters allow the PIDB-1 elastomer to possess physical and chemical recyclability. When using PIDB-1 as a polymer matrix for carbon fiber-reinforced polymer composites, the carbon fibers can be fully recycled. This work provides an integrated design strategy for creating transparent, flame-retardant, recyclable polyurethane elastomers combining high strength and toughness based on dynamic borate ester bonds, which is expected to find wide applications in different industries.</div></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106056"},"PeriodicalIF":4.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1381514824002311/pdfft?md5=bd05a46010363b5a2b88d6f61dedc2b8&pid=1-s2.0-S1381514824002311-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel bio-based propylene-derived phthalonitrile compounds: Synthesis, curing behavior and thermal properties","authors":"Zhiyi Guo,&nbsp;Qiufei Chen,&nbsp;Zhicheng Wang,&nbsp;Athar Ali Khan Gorar,&nbsp;Jun Wang,&nbsp;Wenbin Liu","doi":"10.1016/j.reactfunctpolym.2024.106058","DOIUrl":"10.1016/j.reactfunctpolym.2024.106058","url":null,"abstract":"<div><p>Bio-based bisphenol compounds were prepared using eugenol from biomass as the initial raw material. A reaction of nucleophilic substitution takes place with 4-nitrophthalonitrile in an environmentally friendly solvent to produce bio-based propenyl-derived phthalonitrile monomers. The effective preparation of compounds was proven using hydrogen and carbon nuclear magnetic resonance and fourier transform infrared spectroscopy (FT-IR). By employing the process of free radical catalysis, it is possible to directly cure the novel phthalonitrile monomers without the need for a specific small molecule curing agent. The cured resin was reported to have high glass transition temperature, good thermal stability, and processing properties by FT-IR, differential scanning calorimetry, thermogravimetric analyzer, dynamic mechanical analyzer, and rheometer techniques. The flexural test and scanning electron microscopy results show that both resins have a consistent, flawless structure and improved mechanical properties. Eugenol is derived from sustainable biomass, offering an environmentally friendly approach to utilizing biological monophenols effectively. It provides the benefits of carbon reduction and renewability, making it a valuable and eco-conscious resource.</p></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106058"},"PeriodicalIF":4.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical stable, self-healing and reprocessable multifunctional polymer with dynamic piperazine-hindered urea bonds","authors":"Jingjing Qin ,&nbsp;Jiaming Liu ,&nbsp;Dingsong Wang ,&nbsp;Wanyan Li ,&nbsp;Youwei Zhu ,&nbsp;Liyan Liang ,&nbsp;Chaolong Yang","doi":"10.1016/j.reactfunctpolym.2024.106057","DOIUrl":"10.1016/j.reactfunctpolym.2024.106057","url":null,"abstract":"<div><p>In order to address the relative brittleness and non-recyclability defects of traditional cross-linked epoxy resins, a novel self-healing and reprocessable epoxy resin based on dynamic piperazine-hindered urea bonds (PA-HUBs) was synthesized. Piperazine is a cheap cyclic diamine, which can regulate the skeleton stiffness of epoxy network and control the mechanical properties of epoxy materials. The tensile strength of cured epoxy resin reaches 103 MPa. In addition, the piperazine monomer contains two methyl substituents and an asymmetric aliphatic ring structure, which provides sufficient chain mobility to activate dynamic exchange reactions, and imparts highly dynamic properties to the conventional urea bond, allowing the urea bonds to possess both stability and dynamic properties. Consequently, the synthesized epoxy resin exhibits not only the excellent mechanical performance but also the remarkable self-healing, reprocessable, shape memory and shape reconfiguration capabilities. The epoxy samples with scratches can basically achieve self-healing within 10 min, and the mechanical properties recovery rate of welded splines is as high as 80 %. Furthermore, we also regulated the content of dynamic PA-HUBs and the cross-linking density of the resin network to examine their impact on the dynamic properties and mechanical performance. Further analysis showed that the higher dynamic bond content and lower cross-linking density increase the free volume of dynamic bond exchange and the stress relaxation rate, which further improves the exchange efficiency of dynamic bonds and endows the resin with better self-healing ability. This kind of piperazine-hindered urea bond, which is dynamically adjustable and has both mechanical stability and dynamic properties, introduces a novel approach for solving the balance problem between the mechanical and dynamic performance of thermosets and preparing dynamic polymer materials with excellent performance.</p></div>","PeriodicalId":20916,"journal":{"name":"Reactive & Functional Polymers","volume":"205 ","pages":"Article 106057"},"PeriodicalIF":4.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}