Materials
·
2024
·Vol. 17
·期 17
·4411
·
IF 3.1
Cong Peng,Tao Luo,Zhanjun Wu,Shichao Li
The bisphenol A-type phthalonitrile (BAPH) was blended with the classic epoxy system E51/DDS to prepare the epoxy/phthalonitrile thermoset. The curing kinetics were investigated by differential scanning calorimetry (DSC) using the isoconversional principle, and the average activation energy (Eα) of the E51/DDS curing reaction was found to decrease from 87 kJ/mol to 68.6 kJ/mol. Combining the results of the rheological study, the promoting effect of phthalonitrile on the crosslink of epoxy/amine is confirmed. The curing reaction of the blended resin was characterized using FTIR, and the results showed that BAPH could react with DDS. The thermal behaviors of the thermosets were investigated via DMA and TGA. The glass transition temperature (Tg) is found to increase from 181 °C to 195 °C. The char yield increases from 16% to 59.6% at 800 °C in a N2atmosphere, which is higher than the calculated value based on the proportional principle. The AFM phase images show that there is no phase separation in the cured thermoset. The results imply that the cured epoxy/amine/phthalonitrile blend is probably a kind of copolymer. The real-time TG-MS indicated that the pyrolysis of the thermoset can be divided into two relatively independent stages, which can be assigned to the cleavage of the E51/DDS network, and the phthalocyanine/triazine/isoindoline, respectively.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 20
·48682
·
IF 2.188
Yue Liu,Jinwei Zhang,Wuyong Chen,Didier Astruc,Haibin Gu
Given the toxicity of chrome tanning in leather industry, ecologically compatible alternatives are intensively researched, in particular on the side of aluminum tanning. Herein, the tanning reaction of aluminum with collagen was investigated using microwave irradiation as a new heating method, and the traditional water bath heating (WBH) was used as control. Results from dynamic light scattering and very-positive differential scanning calorimetry (DSC) analysis reveal that, microwave heating led to larger particle size and increased main denaturing transition temperature of collagen clusters crosslinked by aluminum sulfate. The aluminum-tanned collagen products obtained under microwave and WBH methods were further compared and characterized using many techniques including circular dichroism, fluorescence spectroscopy, atomic force microscope, and Fourier transform infrared spectroscopy, DSC, and thermogravimetry. Results verified that both heating methods accelerate the crosslinking reaction of aluminum with collagen and increase the crosslinking degrees. The crosslinked products exhibited improved thermal stability, but no change was observed concerning the binding mode of aluminum with collagen. However, compared to WBH microwave heating has a more positive effect on the aluminum-tanning processes for the improvement of collagen crosslinking processes and product performances, probably due to both thermal and nonthermal effects of microwave irradiation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137 , 48682.
研究领域:
生物化学
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材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2020
·Vol. 221
·期 11
·2000071
·
IF 2.335
Xiuxiu Wang,Nan Zhao,Ban Qin,Jiaojiao Xu,Wenlong Yang,Chensha Li,Liguo Sun,Jianqi Zhang
For the first time, an ultrasonics sonochemistry method is developed to promote the one-pot hydrosilylation polyaddition polymerization and crosslinking reaction in the preparation of polysiloxane main-chain liquid-crystalline elastomers (MC-LCEs). Due to the extraordinary effect of acoustic cavitation, the polyaddition polymerization and crosslinking reaction can be successfully carried out in an ordinary laboratory ultrasonic cleaner at room temperature, and generates the LCE matrix network in about 30 min. The prepared MC-LCEs demonstrate good quality, good properties, and stimuli-actuation performances. Compared to the traditional thermal processing methods for preparing polysiloxane MC-LCEs, this method exhibits superior properties rapidly, with high convenience and efficiency, and can be a path for batch fabrication at low cost. The work also demonstrates that the ultrasonics sonochemistry method is effective in generating linear main-chain liquid crystal polymers through hydrosilylation polyaddition and polysiloxane side-chain LCE matrix through hydrosilylation crosslinking reaction, thus confirming the high availability of ultrasonics sonochemistry in the processes of hydrosilylation polymerization, crosslinking reactions, or synchronous polymerization and crosslinking reactions.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2025
·
IF 4.1
JianZhang Niu,JiaYao Cheng,ZongLin Yi,ChangJun Wang,XiaoMing Li,JingPeng Chen,LiJing Xie,YongGang Chang,XiuChun Li,FangYuan Su,ChengMeng Chen
Cross-linking of coal is an effective method for the preparation of modified coal-derived hard carbon (HCs). However, the complex molecular structure and the lower reactivity of coal hinder its cross-linking, which is not beneficial to the preparation of high-performance coal-derived hard carbon. Herein, a swelling strategy is proposed to improve the reactivity of coal molecules with their cross-linking mechanisms with sucroce. It is found that swelling destroys the hydrogen bonding network in coal molecules, producing aliphatic structures and carboxyl functional groups. Therefore, it improves coal molecular reactivity which is conducive to the formation of an abundant C=O/O=C–O three-dimensional structure and a stable cross-linking structure during the high temperature carbonization procedure. The swelling treatment further enlarges the layer spacing of the carbon material, leading to a greater disorder in the carbon structure, and facilitates the development of pore structure. The HCs with optimal structure exhibit a high initial coulombic efficiency of 88.4 %, a reversible capacity of 304.7 mAh g −1 , and a excellent rate performance (192 mAh g −1 at 1 A g −1 ). This work provides a molecular structure modulation strategy for the modification of coal-derived HCs with potential application in advanced sodium ion batteries.
研究领域:
材料科学
·
能源化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 17
·7887-7898
·
IF 2.302
Lian Qingsong,Li Yan,Yang Tao,Li Kai,Xu Yifen,Liu Liang,Zhao Jingbo,Zhang Junying,Cheng Jue
Allyl-based epoxy resin/Sulfur (S) system is a facile and novel dual-curing system which conducts a unique curing mechanism. In this paper, Bisphenol-A diglycidyl ether (BADGE) and 2-Allylphenol (OAP) cured by S were comparatively investigated to clarify the dual-curing mechanism of Epoxy (EP)/Allyl Compound (AC)/S system. When the temperature was above 170 °C, DSC and FTIR data showed that S could cleave to form thiyl radicals, and FTIR, NIR, and 1 H NMR measurements proved the disappearance of allyl groups and the generation of thiol groups by the thiyl radicals abstracting α-H atoms of allyl groups in the OAP/S reaction system. Real-time infrared spectroscopy (RT-FTIR) results showed that the
reaction of the generation of thiol groups is the dominant reaction in the two possible pathways of the OAP/S system; allyl groups and epoxy groups disappeared sequentially in the OAP/S/BADGE system. DSC curve also revealed the one-stage reaction for OAP/S system and two-stage reaction for OAP/S/BADGE system. These data were used to develop a detailed, experimentally validated pathway for the dual-curing of EP/AC/S system, in which thiol groups are important intermediate, and the dual-curing process included the crosslinking of double bonds that initiated by thiyl radicals and the ring-opening reaction of epoxy groups with thiol groups. Besides, the dual-curing mechanism of EP/AC/S system shares a close resemblance to the classical rubber vulcanization mechanism and the recent thiol-ene radical addition mechanism.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2017
·
IF 6.035
Limei Jin,Zhongying Wang,Sunxiang Zheng,Baoxia Mi
A novel polyamide-graphene oxide (PA-GO) membrane was synthesized on a polyethersulfone support by first intra-crosslinking GO aggregates via m-xylylenediamine (MXDA) and then inter-crosslinking GO aggregates via trimethyle chloride (TMC). This method allows for the use of hydrophilic, more porous supports in forward osmosis (FO) membranes, thereby lending much flexibility to membrane synthesis and also potentially reducing internal concentration polarization in FO. The elemental composition, morphology, and hydrophilicity of the synthesized PA-GO membrane were characterized to confirm intra- and inter-crosslinking reactions and understand membrane properties. It was found that the mixing temperature of MXDA and GO should be controlled below 20 ℃ to avoid the formation of large GO aggregates and hence reduce membrane heterogeneity and defects. The performance of the PA-GO membrane was compared with that of a commercial FO membrane using trisodium citrate (TSC), Na 2 SO 4 , and MgCl 2 , respectively, as draw solutes. Under the same osmotic pressure , the water flux of the PA-GO membrane was the highest with TSC as draw solute, moderate with Na 2 SO 4 , and almost zero with MgCl 2 , while the ranking of solute fluxes followed a reverse order, revealing that an effective solute barrier plays an important role in making FO membranes with high water flux and low solute flux.
研究领域:
材料科学
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环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS
·
2019
·Vol. 108
·期 4
·1725-1737
·
IF 2.674
Ping Li,Ailing Zhang,Shuxue Zhou
Polysiloxane-based artificial skins are able to emulate the mechanical and barrier performance of human skin. However, they are usually fabricated in vitro , restricting their diverse applications on human body. Herein, we presented one-component waterborne cross-linkable polysiloxane coatings prepared from emulsified vinyl dimethicone, emulsified hydrogen dimethicone, and Karstedt catalyst capsules that were first synthesized by solvent evaporation method. The coating had good storage stability and meanwhile could form an elastic film quickly through merging of silicone oil droplets and subsequent hydrosilylation reaction. It was found that the mass ratio of vinyl dimethicone emulsion/hydrogen dimethicone emulsion (V/H), and the dosage of Karstedt catalyst capsules (K/(V + H)) were critical to the curing time, morphology, and mechanical properties of the coatings. With appropriate values of V/H and K/(V + H), the polysiloxane film had the mechanical performance comparable to that from solvent-based one. The coating could be topically applied to human skin in vivo and in situ turned into an elastic, invisible thin film with good water resistance. In contrast to those reported polysiloxane materials, the one-component waterborne polysiloxane coating was nontoxic and convenient for in vivo application on human body, making it be a promising candidate as artificial skin in the fields of cosmetics, medical treatment, and E-skin.
研究领域:
材料科学
·
生物医学工程
·
化妆品科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Engineering Materials
·
2023
·
IF 0
Xue Han,Ruisheng Xue
Hypercross-linked porous polymer materials have good stability and can be used as needed by adjusting the hydrophobic/hydrophilic degree of its functional groups/ions and surface, and they can achieve high gas adsorption. In this study, a series of hypercross-linked porous polymer materials with a rich pore structure and excellent gas adsorption ability were synthesized from polynaphthalene and dimethoxymethane by adjusting the added amount of the catalyst and cross-linker. The sample prepared under the optimized conditions of adding 18 mmol catalyst and 9 mmol cross-linker gained the specific surface area of 786 m2 g–1 and 0.58 nm ultramicropores taking up 80% of total pores. In addition, its CO2 uptake was up to 2.75 mmol g–1 at 273.15 K/1.0 bar. After carbonization at 800 °C, this sample had a 710 m2 g–1 specific surface area and a monodisperse pore structure with a pore diameter of about 0.4 nm, and its CO2 uptake increased to 3.81 mmol g–1 at 273.15 K/1.0 bar. The adsorption selectivity coefficients of CO2/N2 and CO2/CH4 for the carbonized sample were 8.5 and 2.3, respectively, by using Henry’s law initial slope method.
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
DOI
Polymer Chemistry
·
2015
·Vol. 7
·期 3
·625-632
·
IF 5.52
Lingxiao Gu,Qingquan Xue,Shusen Peng,Gang Wang,Jin Han,Xuedong Wu
Small molecule inhibitors only form thin films that are composed of a single molecule layer or multiple molecule layers. Polymer inhibitors also cannot form thick or stable films due to the lack of crosslinking. Thus, these inhibitors are unable to provide robust protection for copper against corrosion. Inspired by the “skinning” phenomenon that is often met during the use of polythiol curing agents, we developed a novel and facile strategy that involves the skinning of polythiols on copper to form super thick protective films. Three types of polythiols, named SPT, TPT and LTPT, were prepared via thiol-click chemistry. Upon immersing bare copper into the solutions of the polythiols, Cu–S bonds immediately form to anchor the polythiol chains firmly on the copper surface, and the following Cu2+ catalysed S–S bond formation reaction leads to crosslinking and film formation. For SPT, TPT and LTPT, the film thicknesses were 2.03, 1.16 and 2.88 μm, and a very high inhibition efficiency of 99.81%, 99.96% and 99.68%, respectively, was achieved in 60 min. Neutral salt spray experiments demonstrated that the polythiol films provide excellent protection for over one week, whereas the control copper samples employing benzotriazole and 1-dodecanethiol suffered from severe corrosion in only 4 h. SPT and TPT have a storage problem due to their instability in air, but this problem was solved by using stable LTPT containing latent thiol groups.
研究领域:
材料科学
·
腐蚀与防护
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2013
·Vol. 34
·期 7
·1013-1019
·
IF 1.482
Jianjun Han,Haifeng Lu,Lin Zhang,Jie Zhang,Shengyu Feng
A novel rubber composite of acrylonitrile-butadiene rubber (NBR) filled with gadolinium salt (GS) particles was prepared for the first time and vulcanized via coordination reactions. The resulting materials exhibit good mechanical properties. Structural analyses indicate that the composite is a kind of elastomers based on coordination cross-linking interactions between the nitrile groups (–CN) of NBR and gadolinium ions. The mechanical properties of vulcanized GS/NBR rubber are altered when the cross-link density is changed in the composites. These materials show good irradiation resistance because of the introduction of GS. POLYM. COMPOS., 34:1013–1019, 2013. © 2013 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Meisheng Li,Jie Wang,Shouyong Zhou,Ailian Xue,Feiyue Wu,Yijiang Zhao
Highly water-selective poly(vinyl alcohol) (PVA)/polyacrylonitrile (PAN) pervaporation membranes were prepared by combining self-aggregation crosslinking reactions for PVA through ammonium persulfate (APS) initiations and interface physicochemical structure regulations for PAN supports. The membrane physicochemical properties were tested and the pervaporation performances were investigated by separation of 95 wt% ethanol aqueous. The results showed that the swelling degree and crystalline region of PVA membranes decreased with the increasing of APS content. On the contrary, the gel fraction of PVA membranes increased. Interestingly, the interface physicochemical structure between the PAN support and PVA separation layer played an important role in pervaporation processes. When the PAN supports were treated by sodium hydroxide (NaOH) and tannic acid (Ta), the water fraction in permeation always kept over 99.99 wt%, especially after Ta treatment. After optimization, the membrane based on PVA content of 8 g, 1.25 g self-crosslinking agent of APS and spin-coated onto H 2 -PAN (PAN modified by NaOH and Ta respectively), showed good permeability-selectivity and long-term performance stabilities. The total flux and water content ratio in permeation were 117.6 g/(m 2 h) and 99.99 wt% respectively by using the PVA 8-1.25 /H 2 -PAN membrane. After running for 120 h, the membranes still displayed a good stability for the ethanol dehydration in the pervaporation process. Importantly, the ethanol solution could be concentrated to over 99.99% using this polyacrylonitrile-based self-aggregation crosslinked poly (vinyl alcohol) pervaporation dehydration membrane.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Wen-Bo Wang,Da-Jian Huang,Yu-Ru Kang,Ai-Qin Wang
The novel granular semi-IPN hydrogels were in situ prepared in an aqueous solution by the free-radical grafting and crosslinking reactions among chitosan (CTS), acrylic acid (AA), gelatin (GE) and N , N ′-methylene- bis -acrylamide. The FTIR spectra and elemental analysis confirmed that the AA monomers were grafted onto CTS backbone, and the GE macromolecular chains interpenetrated through the CTS- g -PAA network. The hydrogels are granular, which are composed of numerous micro-spheres according to the scanning electron microscope observations. The gel strength, adsorption, reuse and recovery properties of the hydrogels for Cu 2+ ion were systematically investigated. The results indicate the hydrogel with 2 wt% GE has the highest adsorption capacity of 261.08 mg/g with the recovery ratio of 95.2%. And the incorporation of 10 wt% GE enhanced the storage modulus by 103.4% ( ω = 100 rad/s) and 115.1% ( ω = 0.1 rad/s), and the adsorption rate by 5.67%. Moreover, the adsorption capacity of the hydrogel is still as high as 153.9 mg/g, after five cycles of adsorption–desorption. It was found that the ion-exchange and complexation interactions between the functional groups ( COO − and NH 2 ) of the hydrogels and Cu 2+ ion are the predominant adsorption mechanisms.
研究领域:
材料科学
·
环境科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）