FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Ye Zi,Cuiping Shi,Guangyi Kan,Jiawei Peng,Huan Gong,Xichang Wang,Jian Zhong
The development of genipin modification methods has attracted much attention to improve the functional properties of proteins in the fields of food science . In this work, two types of pH-responsive genipin-crosslinked bovine bone gelatin conjugates with high surface hydrophobicity were developed for emulsion stabilization. One was genipin molecule-crosslinked gelatin conjugates prepared at acidic pH and the other was genipin macromer-crosslinked gelatin conjugates prepared at neutral and basic pH. The degrees of crosslinking increased with the increase of preparation pH. They increased with the increase of genipin-to-gelatin mass ratios at acidic pH, whereas decreased with the increase of genipin-to-gelatin mass ratios at neutral and basic pH. The surface hydrophobicity values, molecular weights, and emulsifying properties (creaming stability, emulsion activity index, and emulsion stability index) of the obtained conjugates increased with the increase of both preparation pH and genipin-to-gelatin mass ratios. This work provided useful knowledge to understand how the preparation parameters (preparation pH and genipin-to-gelatin mass ratio) and genipin structures (molecule and macromer) affect a protein's degrees of crosslinking, physicochemical properties, and emulsifying properties.
研究领域:
食品科学
·
高分子化学
·
胶体与界面科学
·
生物技术
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Zeyu Qin,Xiwen Jia,Qian Liu,Baohua Kong,Hao Wang
In this study, electrospun chitosan/pullulan composite nanofiber films were crosslinked by two green methods (heating and cinnamaldehyde). With the increase of chitosan content, the morphology results indicated that the nanostructures of thermal crosslinking chitosan/pullulan (TCP) and cinnamaldehyde crosslinking chitosan/pullulan (CCP) nanofiber films became more stable. The decreases in weight loss (83.65 % to 43.85 % for TCP and 23.42 % to 15.58 % for CCP) and the increases in water contact angle (31.8° to 54.1° for TCP and 83.65 % to 43.85 % for CCP) confirmed the improved water stability. The decreases in water vapor permeability indicated that the crosslinking processes significantly improved the barrier properties of the films. Mechanical and thermal properties of TCP and CCP films were enhanced respectively. Furthermore, the corresponding properties of CCP films were more excellent than TCP films. FTIR results indicated the occurrence of Maillard reaction during the thermal crosslinking process and Schiff base reaction during the cinnamaldehyde crosslinking process.
研究领域:
材料科学
·
生物医学工程
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DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2022
·
IF 9.879
Qianqian Wang,Pengwu Xu,Weijun Yang,Tianxi Liu,Martin Hoch,Piming Ma
The current cross-link method in rubber industry is suffering from the utilization of toxic curing packages and the release of volatile organic compounds (VOCs). In this work, we propose a green cross-link route to make robust rubber materials. To prove this concept, ethylene-vinyl acetate-glycidyl methacrylate copolymer (EVM-GMA) functionalized with silane groups, i.e., EVM-Si(OC 2 H 5 ) 3 as a model rubber was firstly designed by solvent-free compounding. Then, the silane groups of EVM-Si(OC 2 H 5 ) 3 rubber are hydrolyzed and cross-linked with water molecules. The cross-link density, tensile strength and hardness of the EVM-Si(OC 2 H 5 ) 3 rubber increased gradually with temperature up to 200 °C. Subsequently, the water cross-linked EVM-Si(OC 2 H 5 ) 3 rubber was reinforced with silica (SiO 2 ) that created a secondary network via an in situ interfacial reaction between the –OH groups of SiO 2 and the silane groups of EVM-Si(OC 2 H 5 ) 3 . As a consequence, the SiO 2 nanoparticles could be evenly dispersed in the rubber matrix with strong interfacial bonding . The tensile strength and elongation at break of the EVM-Si(OC 2 H 5 ) 3 /SiO 2 nanocomposites reached to 10.0 MPa and 800%, respectively at a SiO 2 loading of 30 phr. Thus, the new cross-link strategy addressed here may promote the development and application of rubber industry in some environmental-friendly domains.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
Foods
·
2022
·Vol. 11
·期 22
·3722
·
IF 5.561
Hongbin Wang,Yuanfu Zhang,Zhaoting Yuan,Xiaotong Zou,Yuan Ji,Jiayi Hou,Jinfang Zhang,Fuping Lu,Yihan Liu
Until now,Streptoverticillium mobaraensetransglutaminase (TG) is the only commercialized TG, but limited information is known about its selection tendency on crosslinking sites at the protein level, restricting its application in the food industry. Here, four recombinantBacillusTGs were stable in a broad range of pH (5.0–9.0) and temperatures (<50 °C), exhibiting their maximum activity at 50–60 °C and pH 6.0–7.0. Among them, TG ofB. cereus(BCETG) demonstrated the maximal specific activity of 177 U/mg. A structural analysis indicated that the Ala147-Ala156 region in the substrate tunnel of BCETG played a vital role in catalytic activity. Furthermore, bovine serum albumin, as well as nearly all protein ingredients in soy protein isolate and whey protein, could be cross-linked by BCETG, and the internal crosslinking paths of three protein substrates were elucidated. This study demonstratedBacillusTGs are a candidate for protein crosslinking and provided their crosslinking mechanism at the protein level for applications in food processing.Keywords:transglutaminase;enzymatic characterization;structural analysis;crosslinking properties;protein substrate crosslinking mechanism
研究领域:
食品科学
·
生物化学
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2020
·Vol. 12
·期 9
·1989
·
IF 3.426
Saiqi Tian,Yinyan Chen,Yifan Zhu,Haojun Fan
Rhodamine derivatives (RDs) with three reactive hydrogens were synthesized and well characterized by Fourier transform infra-red spectroscopy (FTIR),1H nuclear magnetic resonance (1H NMR) and electrospray ionization mass spectra (ESI mass). Then, the obtained RD was covalently cross-linked into polyurethane (PU) matrix through chemical linkages to fabricate a network structure, and the fluorescent properties, mechanical properties, thermal stability, and emulsion particle size were systematically investigated. Results demonstrate that PU-RD maintains initial fluorescent properties and emits desirable yellow fluorescence under ultraviolet irradiation. Moreover, compared with linear PU without fluorescers, PU-RD shows clearly improved mechanical properties and thermal stability, on account of the formed network structures.Keywords:fluorescent;polyurethane;crosslink;rhodamine
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Zhen Li,Anqi Li,Liang He,Jianbin Min,Shanshan Guan
Endowing rubber with recyclability represents a critical advance for energy conservation. Herein, we report a sustainable and commercially feasible strategy for developing recyclable ethylene-propylene-diene monomer (EPDM) rubber via exchangeable ionic cross-links. Maleic anhydride (MAH) was grafted onto EPDM to produce EPDM-g-MAH, introducing reactive carboxyl moieties; subsequently, bio-derived zinc phytate (ZnPA) was employed as a green cross-linker to form reversible ionic bonds. After the first recycling cycle, the EPDM-g-MAH@ZnPA rubber retained 96% of its tensile strength and more than 99% of its elongation at break. Even after three recycling cycles, the tensile strength remained at 82%. To balance mechanical performance and recyclability, zinc dimethacrylate (ZDMA) was incorporated to construct a dual dynamic cross-linking network. The EPDM-g-MAH@ZnPA/ZDMA-50 composite achieved a tensile strength of 5.86 MPa and a tear strength of 34.2 N/mm. After recycling, it retained 96.8% of its tensile strength and 86% of its elongation at break, exhibiting excellent structural stability during repeated processing. This work presents a bio-inspired, sustainable strategy for designing high-performance recyclable rubber materials by integrating bio-based cross-linkers into dynamic network architectures.
研究领域:
材料科学
·
高分子化学
·
可持续化学
·
橡胶技术
·
绿色材料工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2025
·
IF 4.3
Chenru Tian,Ganggang Zhang,Jun Liu,Liqun Zhang
The conventional curing methods pose a significant environmental threat due to the use of toxic vulcanizing agents, the release of irritating volatile organic compounds, and the difficulties in recycling end-of-life rubber products. This work demonstrates a catalyst-free, facile, and eco-friendly crosslinking strategy based on the reaction between epoxy-functionalized ethylene-propylene-diene monomer (EEPDM) and dicarboxylic acids. The EEPDM was synthesized via a reusable reaction-controlled phase-transfer catalyst. Then, EEPDM could be effectively crosslinked by dicarboxylic acids without additional additives. The increased acidity of dicarboxylic acids could be conducive to improving the crosslinking rate. Moreover, the curing mechanism and the nature of the crosslinks were investigated, which is crucial for the recyclability of rubbers. The dicarboxylic acid-cured EEPDM exhibited undesirable side reactions, the extent of which showed a positive correlation with the acidity of carboxylic groups. This phenomenon could be primarily attributed to acid-catalyzed self-polymerization via epoxide ring-opening mechanisms, which would be detrimental to the reprocessability. Due to the formation of thermally stable ether linkages, the crosslinked EEPDM exhibited enhanced thermal-oxidative aging behavior. Hence, we envision that this catalyst-free, high-efficiency crosslinking strategy may offer a promising bridge between sustainable modification and high-performance for epoxy-functionalized rubbers, holding potential application in eco-friendly, low-odor automotive sealing strips.
研究领域:
高分子科学
·
材料工程
·
绿色化学
·
橡胶技术
·
化学合成
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2024
·
IF 5.1
Falin Li,Yi Wang,Qiu Wang,Binbo Wang,Shuai Du,Fengyuan Zhang,Songqi Ma
This work discloses a new strategy based on dynamic cross-linking chemistry to achieve advanced one-component thermosets combining ultralong storage life and fast cross-linking. One-component thermosets containing resin and cross-linker in one pot have the features of simple operation, stable quality, and low waste; however, an urgently needed one with long storage life at room temperature and fast cross-linking at medium–low temperatures (≤130 °C) remains an enormous challenge. Herein, we innovatively propose a strategy of dynamic cross-linking and controlled dissolution to address this issue. As an example, a dynamic cross-linked cross-linker (DCC) is synthesized via Diels–Alder reaction to hide the high activity of a commercial amine-type cross-linker. A one-component thermoset from a DCC and a commercial diepoxy monomer can be stored for an ultralong time at room temperature and cross-linked rapidly below 130 °C. Moreover, the DCC can also serve as a latent accelerator for epoxy/anhydride thermosets with the same storage life as the control system with no accelerator at room temperature and fast cross-linking at elevated temperatures. This work is beneficial for promoting the application of dynamic cross-linking chemistry and meeting the urgent need for advanced one-component thermosets in the fields of advanced composites, coatings, electronic packaging materials, automotive and electronic adhesives, etc.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Jinghan Wu,Tianhao Yang,Peng Dong,Qin Zhang,Ke Wang
Ultrahigh-molecular-weight polyethylene (UHMWPE), with its excellent wear resistance and biocompatibility, has important application as artificial joints. The most commonly used method to improve its wear resistance is to introduce crosslinking through irradiation. However, free radicals are introduced after radiation, which are easy to cause inflammation in the human body. Some antioxidants, such as vitamin E ( V E ), need to be added. However, the addition of V E could reduce the crosslinking density of UHMWPE and worsen the wear resistance of the material. Therefore, obtaining new antioxidants that could eliminate free radicals without affecting or even improving the crosslinking density of materials during irradiation is an important subject worth exploring. In this paper, a kind of natural polyphenol substance, resveratrol (RSV), was introduced as a new antioxidant and crosslinking promoter during irradiation crosslinking of UHMWPE. RSV can better eliminate free radicals than V E and further improve the crosslinking density to obtain UHMWPE materials with excellent oxidation resistance and high wear resistance. The multi-active phenolic hydroxyl structure of RSV molecule provides its free-radical trapping ability, and the appropriate molecular size of RSV may promote the H -type crosslinking of UHMWPE, thereby increasing the crosslinking density. This work provides a new pathway for developing high-performance artificial joint prosthesis materials.
研究领域:
材料科学
·
生物医学工程
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 17
·5857
·
IF 3.748
Muneeb Ahmed,Lisheng Zhong,Fei Li,Nuo Xu,Jinghui Gao
In this research, crosslinked polyethylene (XLPE) is developed with selective content of dicumyl peroxide (DCP), and the influence of microstructural properties and chemical composition on the mechanical and direct current (DC) dielectric properties are investigated. The measurements for the microstructural analysis are taken by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), gel content test and Fourier transform infrared (FTIR). The mechanical properties of XLPE are evaluated by hot-set test. The results of microstructural and chemical composition show that the increase in DCP content increases the crosslinking degree from 74.3% to 81.6%, reduces the crystallinity/lamella thickness from 36.8% to 35.5%/7.6–7.1 nm, reduces the average molecular weight between two crosslinks by 0.01 kg/mol and reduces the oxidation level/carbonyl index. The increase in DCP in XLPE samples decreases the permanent elongation from 2.2% to 0% and elongation rate from 300% to 80% of the cable insulation. The rise in DCP content increases the crosslinking degree due to which the DC resistivity and activation energy is increased. The DC breakdown strength at 30–90 °C is increased due to the increase in crosslinking degree and reduction in carbonyl index/oxidation level. The space charge accumulation is measured at 30 °C under 20–60 kV/mm, resulting in less homo-charges and hetero-charges with the increase in DCP. It is proven that the role of appropriate DCP content is vital in increasing the DC dielectric performance, internal material characteristics and mechanical performance of XLPE.Keywords:crosslinked polyethylene;dicumyl peroxide;crosslinking degree;HVDC;resistivity;breakdown strength;space charge
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Shengyue Tang,Kun Liu,Jingsheng Chen,Yizhi Li,Mingxian Liu,Lu Lu,Changren Zhou,Binghong Luo
The liquid crystal properties and viscoelasticity of the natural bone extracellular matrix (ECM) play a decisive role in guiding cell behavior, conducting cell signals, and regulating mineralization. Here, we develop a facile approach for preparing a novel polysaccharide hydrogel with liquid crystal properties and viscoelasticity similar to those of natural bone ECM. First, a series of chitin whisker/chitosan (CHW/CS) hydrogels were prepared by chemical cross-linking with genipin, in which CHW can self-assemble to form cholesteric liquid crystals under ultrasonic treatment and CS chains can enter into the gaps between the helical layers of the CHW cholesteric liquid crystal phase to endow morphological stability and good mechanical properties. Subsequently, the obtained chemically cross-linked liquid crystal hydrogels were immersed into the desired concentration of the NaCl solution to form physical cross-linking. Due to the Hofmeister effect, the as-prepared dual-cross-linked liquid crystal hydrogels showed an enhanced modulus, viscoelasticity similar to that of natural ECM with relatively fast stress relaxation behavior, and fold surface morphology. Compared to both CHW/CS hydrogels without liquid crystal properties and CHW/CS liquid crystal hydrogels without further physical cross-linking, the dual-cross-linked CHW/CS liquid crystal hydrogels are more favorable for the adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells. This approach could inspire the design of hydrogels mimicking the liquid crystal properties and viscoelasticity of natural bone ECM for bone repair.
研究领域:
材料科学
·
生物材料
·
组织工程
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2021
·
IF 5.985
Noy Cohen,Cong Du,Zi Liang Wu
The submersion of a polymer network with a high density of hydrogen bond based cross-links in an aqueous bath results in the formation of a rubberlike hydrogel. The cross-links, which connect chains and maintain the structure of the network, can dissociate as a result of two main factors: (1) the interactions between the hydrogen bonds and the surrounding water molecules and (2) the forces that are exerted on the cross-link from the interconnected chains. We recall that these forces depend on the ratio between the end-to-end distance and the overall contour length of the chains. The application of an external loading translates into the stretching of chains in the network and, as a consequence, an increase in the forces that are exerted. Sufficiently large external loadings can break cross-links and alter the microstructure of the network. From a macroscopic viewpoint, the breaking of cross-links leads to significant microstructural changes such as a reduction in the chain density and an entropic gain. In this work, we derive a microscopically motivated and energy-based model that captures the effects of hydration and external loadings on the overall changes in properties and mechanical response of hydrogels. We provide a systematic method to estimate the percentage of cross-links that dissociate due to hydration and application of a force and provide representative examples to highlight the influence of the orientations of the interconnected chains with respect to a cross-link. To validate the model, we carry out uniaxial tension experiments on poly(methacrylic acid) hydrogels with five different water contents and fit the model parameters. We show that the model is capable of qualitatively and quantitatively capturing the experimental results. The model is also used to approximate the number of cross-links that dissociate due to the water and the externally applied uniaxial force. This work paves the way to the efficient design of multifunctional synthetic hydrogels with programmable properties and behaviors.
研究领域:
材料科学
·
生物工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）