最新刊期
卷 54 ， 期 4 ， 2023
- 摘要：Cyclic polymers exhibit unique properties in comparison with their linear analogs. However, it remains challenging to develop highly efficient and controllable strategy for synthesis of cyclic polymers. Recently, Prof. Zhang group from the State Key Laboratory of Supramolecular Structure and Materials at Jilin University, designs and synthesizes an intramolecularly, covalently tethered B-P-B trifunctional frustrated Lewis pair catalyst/initiator, composed of two acidic B sites and one basic P sites. Through both the intramolecularly-and intermolecularly synergistic effect, such B-P-B system exhibits "one plus one is greater than two" effect, thus successfully polymerizing γ-methyl-α-methylene-γ-butyrolactone (MMBL) into an authentic cyclic polymer c-PMMBL composed entirely of acrylate monomer units. Compared with traditional strategies, this method exhibits good generality and can be employed for rapid synthesis of cyclic polymers, suggesting its potential application in the scalable synthesis of cyclic polymers in the future.关键词：Cyclic polymer;Frustrated Lewis pair;Trifunctional catalyst;Intramolecular synergistic effect;Intermolecular synergistic effect
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发布时间：2023-03-08
Highlight
- 摘要：Metal-backboned polymers (MBPs) are a new class of materials with metal atoms for backbones, which offer excellent electronic properties for promising applications in a variety of fields such as optoelectronics, sensing, and energy storage. However, it remains challenges to synthesize MBPs with high molecular weights for practical applications. Here, the structures of nickel-backboned polymers (NiBPs) with increasing molecular weights were optimized by density functional theory (DFT) method, based on which their stabilities were further studied. It was found that the energies of NiBPs gradually decreased with the increasing molecular weight, indicating that NiBPs with higher molecular weights showed stable molecular configurations. However, with the further increase of molecular weights, it was difficult for NiBPs to converge by DFT method. To this end, these structures were further studied by Hartree-Fock method. Similar results had been concluded as DFT calculation did, and it also proved that an NiBP with molecular weight exceeding 1×104 was also stable. In addition, the unique metal-metal interaction of the electron delocalization on the whole metal backbone is conducive to the efficient transmission of charge. As polymers with repeating metal atom units, MBPs are expected to have combined properties of metal and polymer materials, and may demonstrate high thermal weight loss temperatures and entropy elasticities. This work provides a theoretical basis for the synthesis of MBP materials.关键词：Metal-backboned;Nickel;Polymer;Molecular simulation
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发布时间：2023-03-08
Rapid Communication
- 摘要：As emerging high-tech and intelligent display technologies allowing for real-time human-computer interactions, virtual reality (VR) and augmented reality (AR) can provide completely immersive virtual scenes to users or offer users the perfectly merged scenes of real world with virtual objects. Their unique capabilities are primarily ascribed to the predesigned optical elements in the VR/AR setups. Since multifunction integration, weight reduction and customization of VR/AR setups are in urgent needs for developing advanced VR/AR technologies, it is critical to develop novel optical elements using advanced materials. To this end, holographic polymer materials can play a central role. In this feature article, the VR/AR near eye display systems and key parameters are firstly overviewed, followed by the discussion of the application of holographic polymer materials in VR/AR display. Subsequently, the relationship of VR/AR performances to the properties of holographic polymer materials is discussed, and strategies to improve the refractive index modulation, decrease the scattering loss and volume shrinkage of holographic polymer materials are highlighted. Finally, the shortage and future directions of current holographic polymer materials are pointed out, respectively, for advancing the VR/AR technologies.关键词：Virtual reality;Augmented reality;Holographic optical elements;Holographic polymer materials
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发布时间：2023-03-08
Feature Article
- 摘要：The physical properties of polymer glasses are closely related to their structure and dynamics. A deep understanding of the microscopic physical mechanism of polymer glass formation is crucial for the structural control and molecular design of polymer glasses. However, various molecular characteristics associated with complex segmental structures and chain topology of polymers impose significant challenges for the development of a fully predictive theory to describe their glass formation in a quantitative way. Hence, it is highly desired to develop more advanced approaches to better understand and predict polymer glass formation. In recent years, growing efforts have been made to shed new lights on polymer glass formation based on the data-driven informatics approaches, such as machine learning, and important progresses have been made towards this direction. The present review first introduces common polymer databases and machine learning algorithms, followed by a summary and review of the representative progresses on the applications of machine learning methods in the studies of polymer glass formation. In particular, the focus is placed on the prediction of the glass transition temperature, the research and development of novel glassy polymer materials, the investigation of structure-dynamics relationships of glass-forming liquids, and the determination of phase transitions of glasses. Finally, the present review discusses challenges and opportunities in the applications of machine learning methods to polymer glass formation and provides a perspective on glass informatics.关键词：Informatics;Polymer glass formation;Machine learning;Theory and simulation
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发布时间：2023-03-08 - 摘要：Protein drugs have a wide range of applications in the treatment of many diseases. However, the poor cell membrane penetration of protein drugs often leads to low bioavailability. In recent years, a series of nanocarriers have been developed to improve the efficiency of intracellular delivery of protein drugs. Among them, nanocarrier based on phenylboronic acid and its derivatives have shown good application prospects. This paper reviews the latest research progress of phenylboronic acid-functionalized polymer nanocarriers for intracellular delivery of protein drugs. Firstly, the chemical properties of phenylboronic acid and its responsiveness to diols, pH and ROS are briefly introduced. Secondly, from the perspective of different binding modes of phenylboronic acid and protein drugs, this review focuses on the typical research examples of phenylboronic acid-functionalized polymer nanocarriers constructed by dynamic covalent bonds and non-covalent interactions such as N→B coordination in the intracellular delivery of protein drugs. The compositions, construction method, and responsive release mechanism of these nanocarriers are analyzed and summarized. Finally, the research progress of phenylboronic acid in enhancing cell uptake and drug permeation through blood brain barrier is introduced. It is hoped that this paper can provide a reference for the design and preparation of novel intracellular delivery systems of protein drugs based on phenylboronic acid.关键词：Protein drugs;Intracellular delivery;Phenylboronic acid;Responsive release;Nanocarriers
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发布时间：2023-03-08
Review
- 摘要：Thiopolyesters is a new type of materials that combine the advantages of polyester materials (degradability, biocompatibility, thermal stability, etc.) and sulfur-containing polymer materials (optical properties, metal adsorption properties, etc.). In this study, the sulfur-containing carboxyanhydride (5-methyl dithiolane-2,4-dione, MDTD) was synthesized and polymerized by Schiff base-manganese (Salen-Mn). The formation of small-molecule by-products was inhibited and the active homopolymerization of MDTD was realized under the condition of low feed ratio (50:1) using 4-dimethylaminopyridine (DMAP) as cocatalyst, at lower temperature (60 ℃). Based on the reversible insertion of carbon oxysulfide (COS) by Salen-Mn, a new monomer controlled self-switchable polymerization route was developed by sequentially addition of the MDTD and the removal of COS. Chemoselective ring opening between MDTD and lactide (LA) was explored with DMAP as cocatalyst. The monomer controlled switchable copolymerization reaction process and the formation of polyblock polyester/polythioester (p(LA-b-MDTD-b-LA)) were confirmed by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). Eventually, a two-step switchable copolymerization was realized by sequential addition of MDTD and degassing, a five-block polyester/polythioester (Mn = 12.4 kg/mol, Đ=1.20) copolymer was obtained. This emerging polymerization strategy could synthesize the corresponding multi-block polyester/polythioester by changing the structure of the Sulfur-containing carboxyanhydride monomer, which lays a foundation for improving physical and chemcial properties of the thiopolyesters.关键词：Switchable copolymerization;Sulfur-containing Carboxyanhydride;Polythioseters;Ring-opening copolymerization (ROCOP);Multi-block copolymer
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发布时间：2023-03-08 - 摘要：The copolymerization product of epichlorohydrin (ECH) and carbon dioxide (CO2) has the modifiable C―Cl bond, which is an effective way to functionalize polycarbonate. However, the reaction has been limited by a long induction period. Herein, we propose a strategy to enhance the copolymerization activity induced by trace anhydride, i.e., introducing trace cyclic anhydride into the CO2/ECH copolymerization system to shorten the induction period and improve the reaction activity. Taking zinc-cobalt cyanide complex (DMC) catalyst as an example, the ECH conversion reached 23.6%-83.6% (40 ℃, 24 h) with 0.1 mol% of different cyclic anhydrides in the CO2/ECH copolymerization, and the reactivity was significantly enhanced compared to the low conversion (2.6%) in the system without the addition of anhydride. In particular, the CO2/ECH copolymerization system induced by 5-norbornene-2,3-dicarboxylic anhydride showed the highest activity-enhancing effect, achieving 98.8% ECH conversion in 28 h with a catalytic efficiency of 430 g polymer/g cat. and maintaining 91.3 wt% polymer selectivity. Meanwhile, CO2-based polycarbonate with a CU content of 68.2% and molecular weight of 16.7 kg/mol was effectively prepared. Further, it was confirmed that the preferential copolymerization of cyclic anhydride with ECH to produce polyester active species was the root cause of the shortened induction period and the enhanced activity effect by using online infrared and other spectroscopic techniques. In summary, this paper presents a practical method of anhydride-induced activity enhancement to achieve efficient copolymerization of CO2 and ECH, which provides a new idea for the efficient synthesis of functionalized CO2-based polycarbonate.关键词：Carbon dioxide;Epichlorohydrin;Cyclic anhydride;Induction period;Activity-enhancing
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发布时间：2023-03-08 - 摘要：By integrating the microphase separation and hydrogen-bonding complexation, here, triblock copolymer polystyrene-b-poly(acrylic acid)-b-polystyrene (SAS) and homopolymer poly(ethylene oxide) (PEO) were used to construct the elastomer (SA/E) with different hierarchical structures. Poly(acrylic acid) (PAA) and PEO can form flexible and stretchable hydrogen-bonded complex. Polystyrene (PS) is neither compatible with PAA nor PEO, and the microphase separation structure will be formed when SAS is associated with PEO. The vitrified PS domains acted as physical cross-link points for soft PAA/PEO hydrogen-bonding complex domains. Compared with PAA/PEO homopolymer hydrogen-bonding complex, the SA/E elastomer shows higher modulus and strength, while maintain the considerable breaking elongation. By changing the PS molecular weight fraction, the SA/E can assemble to various microphase structures and present different mechanical and elastic properties. In addition, the SA/E shows excellent humidity adaptable behavior. The SA/E has different mechanical strengths at different relative humidity conditions. The moisture absorbed in SA/E can serve as plasticizer to enhance the flexibility of PAA/PEO hydrogen-bonding complex domains. Moreover, by cyclic stretching-releasing training, the elastic recovery ratio of SA/E is significantly improved, up to 98%. The elastomer has potential application in smart sensors, flexible devices, and advanced medical materials. This research also provides new methods and ideas for constructing new elastic materials.关键词：Elastomer;Polymer complex;Block-copolymer;Microphase separation;Hydrogen-bonding association
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发布时间：2023-03-08 - 摘要：A series of high molecular weight ordered and disordered block sulfonated polyaryle ether sulfone (SPAES) were synthesized using phenyl-containing p-bis(phenylene-tetrafluorobenzene) as a linking agent, with 4,4'-difluorodiphenyl sulfone and 4,4'-dihydroxydiphenyl sulfone and 4,4'-biphenyl sulfone as hydrophobic and hydrophilic block precursors, respectively. The 1H-NMR showed that the sulfonation site of the prepared block SPAES was consistent with the prediction, and the titration value of the ion exchange capacity (IEC) was more than 95% of the theoretical value, indicating that the sulfonation position and sulfonation degree were precisely controllable. The Young's modulus, tensile stress and elongation at break of the SPAES proton exchange membrane in this work are as high as 1.92 GPa, 75 MPa and 58%. The TGA results show that the block SPAES in this work has two stages of weightlessness, namely sulfonated group detachment at about 320 ℃ and polymer skeleton decomposition above 500 ℃. Similar to IEC, the water absorption rate of SPAES with benzene ring large side linker varies significantly less with temperature than that of linkless SPAES, and the rate of change in the size of the membrane surface direction is comparable, both of which are about 8%. The proton conductivity of ordered blocked SPAES with linking agents with similar IEC, such as MB9 (IEC = 1.68 mmol·g-1), is more than 1.2 times that of linkless blocked SPAES B2 (IEC = 1.70 mmol·g-1). This is due to the benzene ring side chain structure of the linker so that the free volume in the membrane increases favors proton conduction. Similarly, the proton conductivity of ordered blocked SPAES PEM is higher than that of the same IEC type of disordered block.关键词：Sulfonated polyaryle ether sulfone;Linking agent;Proton exchange membrane;Post-sulfonating;Controllable degree of sulfonation
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发布时间：2023-03-08 - 摘要：Recently, the problem of air pollution has become more and more serious. The preparation of high-efficiency air filter materials (AFMs) is of great significance in solving the air pollution problem. In this study, the micro/nanostructured PP/ZIF-L melt-blown AFMs were prepared via in situ growth method with the PP melt-blown AFMs as the matrix. The in situ growth of ZIF-L can effectively regulate the structure and properties of PP melt-blown AFMs, and thus solve the shortcomings of PP melt-blown AFMs with poor filtration stability and non-reusability. The effects of in situ growth of ZIF-L on the structure and properties of PP melt-blown AFMs were investigated by various methods. The results showed that the in situ growth of ZIF-L can effectively improve the filtration performance of PP melt-blown AFMs. The filtration efficiency of PM2.5 increased from 55.2% to 93.2% after the growth of ZIF-L on PP melt-blown AFMs' surface. Moreover, the PP/ZIF-L melt-blown AFMs had excellent reusability. The PP/ZIF-L melt-blown AFMs still showed a higher filtration efficiency (92.4%) after washing with 75% alcohol, while that of the commercial PP melt-blown AFMs was only 56.8%. The PP/ZIF-L melt-blown AFMs showed a broad application prospect in the field of air filtration and can provide a certain reference for the preparation of high-performance PP melt-blown AFMs.关键词：In situ growth;Zeolitic imidazolate framework;PP melt-blown air filter materials;Tannic acid;Air filtration performance
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发布时间：2023-03-08 - 摘要：The hyper-cross-linked polymers (HCPs) are considered one of the most famous porous organic polymers for their great advantages of high Brunauer-Emmett-Teller (BET) surface area (SBET), abundant micropores, and tunable porosity. Furthermore, the extensive aromatic monomers, inexpensive Lewis acid catalysts, and simply construction process make the HCPs developed greatly. In this way, the Friedel-Crafts alkylation was widely used for the construction of HCPs. However, the shortage of functional groups and reaction sites make the HCPs limited in the adsorption performance. The Friedel-Crafts acylation would take ketone carbonyl to the resulting polymers, which will performed well in the adsorption performance after the post-functionalization. However, it is still difficult to construct the HCPs with high SBET through Friedel-Crafts acylation. Therefore, in this work, a series of porphyrin-based polymers with high specific surface area was constructed through the Friedel-Crafts acylation reaction by using three different acylated crosslinking agents (p-phthaloyl chloride, trimesoyl chloride, and oxalyl chloride) and 5,10,15,20-tetraphenylporphyrin. The polymers show abundant ketone carbonyl groups. Therefore, thiosemicarbazide, which has amino and thiourea structure, was used for post-functionalization through Schiff-based reaction and a series of functionalized porphyrin-based polymers were obtained. Due to the hyper-cross-linked structure of the polymer with high SBET and abundant micropores, The polymer showed remarkable CO2 adsorption performance (138 mg/g, 273 K, 105 Pa) and excellent CO2/N2 selectivity. Remarkable, the post-functionalization of thiosemicarbazide decreased the SBET and the Vmicro of the polymers, the introducing of the N and S heteroatoms greatly improved the CO2 adsorption capacity for the strong interaction between the heteroatoms and the CO2 moleculars. Especially for HTMb-TSC, the post-functionalization make the CO2 capture capacity increased from 37 mg/g to 91 mg/g (273 K, 105 Pa). At the same time, the adsorption capacity of Hg2+ was increased from 210.2 mg/g to 311.0 mg/g due to the introduction of amino and thiourea structures, and the adsorption mechanism also confirmed the coordination between N and S with Hg2+. The porphyrin-based polymers also showed good reusability. This work confirmed the advantages of the porphyrin structure in the adsorption applications and expand the application of Friedel-Crafts acylation reaction in the construction of porous organic polymers.关键词：Friedel-Crafts acylation reaction;Schiff-based reaction;Porphyrin;CO2;Hg2+
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发布时间：2023-03-08
Research Article
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