最新刊期
卷 37 ， 期 12 ， 2024
- 摘要：Papermaking is one of the four great inventions of ancient China. Traditional Chinese paper is an important carrier of the long history and culture of the Chinese nation, and its development has spanned thousands of years. The invention of paper has played a great role in promoting the development of human civilization. This review begins with the historical evolution of human writing materials, and focuses on paper, the most important and common writing medium for human beings. In detail, this review first briefly looks back the history about the spreading of traditional Chinese papermaking technology, and accordingly comments on its far-reaching impact on human cultural communications and the development of world civilization. On this basis, this review discusses a series of issues such as the estimation of paper lifetime, the settling of fibers, the production of curtains, etc., in the light of many scientific problems related to traditional Chinese papermaking technology and paper properties, combined with the application of paper relics conservation. Furthermore, this review also focuses on the use of polymers and other related materials in the conservation of paper-based cultural relics. It provides a fresh perspective and new solutions for the long-term preservation and scientific restoration of paper-based cultural relics.关键词：Traditional Chinese paper;Papermaking craft and paper properties;Durability and paper-lifetime estimation;Paper relics conservation
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发布时间：2024-12-12 - 摘要：Semiconducting polymers, especially π-conjugated donor-acceptor (D-A) copolymers with defect-free alternating structures, are essential materials for plastic electronics and optoelectronics owing to their tunable chemical structures, tunable bandgaps and optical absorptions, excellent charge transport mobility, mechanical flexibility, and solution processability for printing. However, traditional synthesis methods may cause homocoupling structural defects, resulting in large batch variations, thus hindering the large-scale commercial application of polymer semiconductors. This study reviews the effect of homocoupling structural defects of conjugated polymers on their photoelectric properties, aiming to reveal the importance of precise synthesis on the performance of conjugated polymers. We believe this review will guide the precise and large-scale production of high-performance polymers, potentially catalyzing advancements in their industrial applications.关键词：Polymer semiconductor material;Homocoupling structural defects;Optoelectronic property
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发布时间：2024-12-12 - 摘要：Thermosetting adhesives have the characteristics of excellent bonding properties, electrical insulation properties, chemical resistance, heat and high temperature resistance, and are widely used in automotive, electronics, power generation, aerospace and other fields. However, the three-dimensional cross-linked networks make thermosetting adhesives insoluble and non-melting, thus leading to the difficulties of rapid disassembling, maintaining and even recycling the bonded components or parts. Dynamic covalent bonds can be introduced into the cross-linked networks of adhesives to form covalent adaptable networks, which can result in reversible fracture of cross-linked networks under specific conditions, thereby achieving controllable debonding. Many studies have been carried out in the field of controllable debonding adhesives based on dynamic covalent bonds, and a series of new adhesives based on dynamic covalent bonds have been developed. This review mainly introduces the current research progress of controllable debonding adhesives based on dynamic covalent bonds, especially focuses on the basic principle of the design and preparation of these adhesives, summarizes the relationship between covalent adaptable network structures and properties of different types of controllable debonding adhesives, and looks forward to their development trends and challenges.关键词：Adhesives;Adhesive properties;Dynamic covalent bond;Covalent adaptable networks;Controllable debonding
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发布时间：2024-12-12 - 摘要：Polyurethanes are among the most commonly used polymeric materials in daily life and industry due to their excellent combined properties. Conventional polyurethanes are mainly prepared by the reaction of polyols and highly toxic diisocyanates or polyisocyanates. In the current context of sustainable development, functional non-isocyanate polyurethanes are highly valued because they are prepared without the use of toxic isocyanate raw materials, and at the same time, they can meet the growing demand and market variety. In this review, the preparation routes of non-isocyanate polyurethanes with application prospects were summarized, and reaction routes based on cyclic carbonate and dimethyl carbonate, as well as their advantages and disadvantages, were discussed in detail. The application progress of functional non-isocyanate polyurethanes in fields of self-healing materials, shape memory materials, reprocessable materials and adhesion was also discussed in detail, and the future development direction and trend were prospected.关键词：Non-isocyanate;Polyurethane;Functionality;Environmentally friendly
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发布时间：2024-12-12 - 摘要：Urea formaldehyde (UF) resin is widely used as an adhesive in the production of artificial boards because of the advantages of low cost and easy preparation. However, the UF resin adhesive can undergo chemical bond breakage and release formaldehyde under the attack of water molecules, which reduces the performance of UF resin. By adding nanomaterials to the UF resin adhesive, the nanoparticles can physically or chemically interact with the UF resin, thereby modifying and improving the resin. This article summarizes the methods for modifying UF resin adhesives by nanomaterials. The nanomaterials applied in recent years are classified into elemental, metal oxide, non-metal oxide, inorganic salt, and organic macromolecule nanomaterials. The reaction mechanism, production process, and modification effects are summarized. Nanomaterials modify UF resin through mechanisms such as photocatalytic oxidation, intermolecular forces, and hydrogen bonding. For different nanomaterials, selecting the suitable reaction raw material ratios, the time and amounts of nanomaterials additive and the temperature of chemical reaction can optimize production processes, reduce formaldehyde emissions, and enhance resin bonding properties. After being modified, nanomaterials can be better applied to modify UF resin. They are expected to increase new reaction sites and improve the compatibility between nanomaterials and UF resin, which has certain research and application prospects.关键词：Urea formaldehyde resin;Adhesive;Nanomaterials;Modification
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发布时间：2024-12-12 - 摘要：With the rapid advancement of industrialization and urbanization, the issue of heavy metal pollution in water resources has been increasingly exacerbated, posing significant threats to both human health and ecosystems. This paper provides a detailed discussion on applying four principal methods for modifying nanocellulose for heavy metal ion adsorption: oxidation modification, esterification modification, etherification modification, and graft copolymerization modification. These methods significantly enhanced the adsorption capacity of nanocellulose for heavy metal ions by increasing the functional groups on its surface. Finally, future research directions for modified nanocellulose in heavy metal ion adsorption are explored, emphasizing the importance of selectivity, reducing costs, improving adsorption efficiency, and ensuring sustainability.关键词：Nanocellulose;Heavy metal ions adsorption;Oxidative modification;Esterification modification;Etherification modification;Graft copolymerisation modification
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发布时间：2024-12-12 - 摘要：Cyanate ester resins (CE),which have excellent mechanical properties, good thermal stability and very small dimensional shrinkage, are widely used in electronic packaging and other fields. In this study, the synthesized phenolic hydroxyl-substituted spirofluorene-xanthene-type fully rigid polyimide (PI-OH) was used to modify bisphenol A-type cyanate ester resin (BADCy). It was found that the phenolic hydroxyl groups on the side chain of PI-OH could significantly reduce the curing temperature of BADCy, and the peak exothermic temperature of curing was reduced by about 142 ℃ compared with that of the unmodified resin. At room temperature, the energy storage modulus and Young’s modulus of PI-OH(10%)/BADCy were 2614 MPa and 5010 MPa, respectively, which were increased by 34% and 10.2%, respectively, compared with those of pure BADCy. In addition, the tensile strength and tensile modulus of PI-OH(8%)/BADCy were increased by 63.9% and 128.4%, respectively, and its thermal degradation temperature (Td5%) and statistical heat resistance index (Ts) were enhanced, although the glass transition temperature (Tg) was slightly decreased. Meanwhile, the water absorption of the PI-OH(10%)/BADCy system was only 0.73%, which was reduced by 47.9%, due to the large number of hydrophobic trifluoromethyl groups in the side chain of PI-OH. This progress is of great importance for the production of low-temperature curable cyanate ester resin materials with good thermal stability and mechanical properties.关键词：Phenol hydroxyl polyimide;Bisphenol A cyanate ester;Curing temperature;High temperature resistance
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发布时间：2024-12-12 - 摘要：Electrochromic energy storage devices have both electrochromic and energy storage functions, and can indicate the energy storage status through real-time color changes. They have attracted attention in the fields of energy-efficient buildings and intelligent electronics. Polyaniline (PANI) has rich color changes and a high theoretical specific capacitance, and occupies a place in the fields of electrochromism and energy storage. In this study, in order to improve the capacitance of polyaniline, reactive blue 19 (RB19) with redox activity was added when the polyaniline film was prepared via galvanostatic method, and polyaniline was doped by electrostatic interaction. The effects of the ratio of aniline to reactive blue 19 and the deposition time on the morphology and electrochemical performance of the polyaniline film were analyzed. The electrochromic energy storage device was assembled using indium-tin oxide (ITO) conductive glass with polyaniline film as the working electrode, ZnCl2 as the electrolyte, and zinc flake as the counter electrode, and the performance was studied. The results show that the doping of reactive blue 19 greatly enhances the capacitance of polyaniline film. At a scan rate of 50 mV/s, the capacitance (C) of PANI-RB19100:1(20min) can reach 3.29 times that of PANI(20min). At a current density of 0.1 mA·cm−2, an area capacitance (Ca) of 32.41 mF·cm−2 can be obtained, and a ten fold increase in current density results in a capacitance retention rate of 78.06%. The electrochromic energy storage device can generate 56.22% spectral modulation amplitude at 750 nm, and connecting the two devices in series can light up a red LED lights more than 3 h.关键词：Electrochromic;Energy storage;Polyaniline;Reactive blue 19
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发布时间：2024-12-12 - 摘要：In recent years, decellularized matrix has shown great potential in tissue engineering, but how to improve its mechanical properties is still a problem. In order to explore the potential of using a composite hydrogel scaffold with silk fibroin (SF) to improve the mechanical properties of decellularized liver matrix (DLM) for liver tissue engineering, four groups of SF/DLM composite scaffolds were prepared by cross-linking the rat liver with SF solution at the same concentration and different volume proportions. The proportions of SF to DLM solution were 100:0, 75:25, 50:50, 25:75, respectively. The morphological structure, in vitro degradability, hydrophilicity, mechanical properties and cell compatibility of the scaffolds were characterized. The results showed that SF could improve the mechanical properties of the composite scaffold, the porosity, pressure resistance, degradability and hydrophilicity of the scaffold were all improved. Combined with the cell promoting function of DLM, the composite scaffold is expected to be applied in liver repair tissue engineering.关键词：Scaffold material;Decellularized matrix;Silk fibroin;Liver tissue engineering
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发布时间：2024-12-12 - 摘要：Different ionic surfactants were applied in this work to modify graphene oxide (GO). Then, a series of functionalized-graphene-oxide@polyvinylbutyral (PVB/f-GO) composites were prepared via the solution blending method. The X-ray diffractometer (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) analyses revealed that the surfactant insertion effectively prevented the aggregation of GO and improved its dispersibility in PVB. The mechanical and optical measurements showed that when 0.02 wt% sodium hexadecyl sulfonate modified graphene oxide (s-GO) was added, the tensile strength of PVB/f-GO composite material was 38.1% higher than that of pristine PVB, while the visible light transmittance was maintained at 88%. When the sodium hexadecylbenzene sulfonate modified graphene oxide (sd-GO) content was 0.03 wt%, the tensile strength of PVB/sd-GO composite materials was increased by 28.4% compared to that of pristine PVB, while the ultraviolet shielding ability was increased above 65%.关键词：Polyvinylbutyral;Functional graphene oxide;Mechanical property;Transparency
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发布时间：2024-12-12 - 摘要：Low-density polyethylene (LDPE) forms a three-dimensional mesh structure after peroxide cross-linking modification and exhibits shape memory properties. The obtained thermoset shape memory polymer (SMP) shows good structural stability and excellent shape recovery, which can maintain high shape recovery (Rr) and fixation rates (Rf) even after multiple cycles. However, thermos-responsive SMP have limited application environments that require direct contact heating to trigger the shape memory effect. By adding functional fillers, it can be endowed with a variety of response modes for applications such as remotely controllable medical devices, soft robotics, and aerospace. In this work, LDPE as a substrate and Fe3O4 as a filler, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexynyl (DTBP) was selected as a cross-linking agent, and triallyl isocyanurate (TAIC) as a co-cross-linking agent, to prepare shape-memory LDPE/Fe3O4 composites with photo-thermal and magnetic responses. By exploring the effect of DTBP content on the properties, it was found that the gel content, mechanical properties, and shape memory properties of the sample showed an increasing trend with the increase of DTBP. It was found that when DTBP content was 2 wt%, the gel content of LDPE/Fe3O4 reached a maximum value of 83.09%. And the mechanical properties had the optimal overall performance, with a tensile strength of 10.03 MPa, 28% higher than that of the uncrosslinked sample; the shape memory performance was also excellent, with a Rr of close to 100%, and Rf reaches 96.52%. At the same time, the LDPE/Fe3O4 has a strong photothermal conversion ability, and can be heated up to 105.6 ℃ within 7 s, and the flower sample returns to the original shape within 18 s.关键词：Crosslinked polyethylene;Shape memory polymer;Photothermal responsive;Magnetic responsive;Fe3O4 nanoparticle
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发布时间：2024-12-12 - 摘要：The integration between industry and education is a new approach that combines the education chain, industry chain, innovation chain, and talent chain. This model provides a fresh strategy for talent cultivation in colleges and universities. Graduation internship is a crucial component of talent cultivation in the specialty of polymer materials and engineering. However, graduation internship encounters some challenges such as outdated knowledge, limited internship opportunities, insufficient quality instructors, inadequate internship platforms, and lack of enterprise engagement. The factors above have significantly impacted the actual effectiveness of the course. The specialty of polymer materials and engineering aims to cultivate applied research talents. Based on the integration of industry and education, a new “quaternity” graduation internship course system comprising curriculum, platfrom, faculty and development community was proposed. This initiative has actively promoted the construction of graduation internship course, established high-level internship platforms, formed engineering practice instructor teams, fostered a development community for education, and implemented an internship quality monitoring system. The teaching reforms and talent cultivation of graduation internships have yielded remarkable results and the internship satisfaction has significantly improved. This approach offers a new perspective on teaching reforms for graduation internships at colleges and universities.关键词：Graduation internship;Industry-education integration;Talent cultivation;Teaching reform
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发布时间：2024-12-12 - 摘要：Polymer chemistry is the primary course for undergraduate students majoring in polymer science. Combing scientific research achievements as extended reading materials is beneficial for undergraduate students to consolidate their knowledge, stimulate their scientific exploration spirit, cultivate their innovation ability, and provide new references for exploring the optimistic interaction between teaching and scientific research. This article integrates the scientific research achievement “1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) applied to verify the free radical polymerization mechanism of aromatic nitrile resin” into the teaching of the free radical inhibition/retardation chapter. As an extended reading material after class, it effectively combines the “pre class-post class” teaching mode to help students strengthen basic knowledge and inspire students to use basic knowledge to solve scientific research issues.关键词：Polymer chemistry;Free radical polymerization;Inhibition/retardation;1,1-Diphenyl-2-trinitrophenylhydrazine;Aromatic nitrile resin
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发布时间：2024-12-12 - 摘要：Polymer Physics is a core course for undergraduate majors such as materials science and engineering, and polymer science and engineering. The Polymer Physics teaching team at school of materials science and engineering of Beihang University performed a discussion-based reform. The team set the discussion themes as representative polymers such as natural polymer, high-performance structural polymer based on teachers’ research directions, establishing object mapping relations with the contents in the textbook. This essay introduces the overall design of the discussion-based reform. Focusing on the case themed of silkworm silk, it also explains in detail how to guide the thinking and discussion of students. This reform significantly raised the participation of students, and cultivated their high-level ability of analytical and problem solving. The results proved that discussion-based teaching was an effective tool to improve the teaching performance of Polymer Physics.关键词：Discussion-based teaching;Case teaching;Teaching model reform;Natural polymer
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发布时间：2024-12-12 - 摘要：Polymer physics, as a core course in the field of polymer science, focuses on the unique physical properties of polymers. The teaching content related to polymer chain structures explains the relationship between the chemical structure and physical properties of polymers, forming the foundation for understanding the macroscopic properties of polymer materials. Plastics, as a major category of important polymer materials, are diverse and complex, with performance differences even among different grades of the same type of plastic. As a precursor course, the teaching content of polymer physics plays a crucial guiding role in the study of plastic materials. This paper uses “polymer chain structure” as an example to explain how variations in the sequence structure of molecular chains, molecular weight and its distribution, and chain topology affect the physical and processing properties of plastics. The use of commercial plastic products as examples enhances the effectiveness of teaching. Students are encouraged to establish connections between the content of different courses, thus building continuity in the teaching content of polymer science. It is of great significance to cultivate students’ ability to construct a systematic knowledge framework in polymer science for their learning and mastery of the subject.关键词：Polymer chain structure;Polymer physics;Plastics
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发布时间：2024-12-12
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