APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Li Dong,Xiangdong Liu,Zhengrong Xiong,Dekun Sheng,Yan Zhou,Changhong Lin,Yuming Yang
Herein, PVDF membranes with excellent UV-absorbing property were first synthesized through grafting the polymerizable low-molecular-weight organic UV-absorber 2-hydroxy-4-(3-methacryloxy-2-hydroxylpropoxy) benzophenone (BPMA) onto α-bromoester-functionalized PVDF membranes via the surface-initiated activator generated by electron transfer atom transfer radical polymerization (SI-AGET ATRP). The surface initiators were immobilized by the reaction between 2-bromoisobutyryl bromide (BIBB) and the hydroxylated PVDF membranes. PVDF-g-PBPMA membranes with different grafting densities were obtained by tuning the polymerization time and the modified membranes were characterized by 1 H-NMR, FT-IR, XPS, SEM, UV–vis Spectrophotometer, TGA and DSC. The experimental results indicated that PBPMA chains were successfully introduced onto PVDF membranes. Most importantly, the PVDF-g-PBPMA membranes exhibited outstanding UV-shielding property. UV–vis transmittance spectra showed that most UV light below 360 nm could be absorbed by PVDF-g-PBPMA membranes and the whole UV light region (200–400 nm) can be blocked with the reaction time increased.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2022
·Vol. 41
·期 6
·637-643
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IF 5.56
Yin Zhang,Yu Wang,Wei You
Comprehensive Summary Polymer functionalization is a powerful tool to prepare polymers with diverse structures without the need of synthesizing monomers or performing polymerization reactions. Polymers that are difficult to be synthesized using direct polymerization reactions can be accessed using polymer functionalization. We herein present Mitsunobu derivatization of poly(vinyl alcohol) (PVA) to convert the hydroxyl groups into diverse functional groups. Partial acetalation strategy is applied to improve solubility of the PVA derivatives in tetrahydrofuran, and more importantly, the acetals can act as protecting groups so that functionalized copolymers are produced. Diverse functions can be introduced into PVA derivatives by installing different functional groups. Transparent, colorless, flexible, and scalable UV-shielding membranes are conveniently prepared in one step using this method.
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2022
·
IF 6.449
Xiao-Li Zhao,Yi-Dong Li,Yunxuan Weng,Jian-Bing Zeng
Biobased epoxy covalent adaptable networks (ECANs) with renewability, recyclability, and reprocessability are thought as ideal alternatives to petroleum-based epoxy thermosets with respect to sustainable development. In this study, biobased ECANs based on dynamic imine bonds were prepared from glycerol triglycidyl ether (GTE), vanillin (VA), and diamines via a facile two-step solvent-free procedure. In detail, a trialdehyde monomer was first synthesized via ring-opening reaction of GTE with VA and then cured with diamines to obtain imine-based ECANs with a carbon biobased content of > 50.0%. The biobased ECANs had an excellent tensile strength (> 70 MPa), Young’s modulus (> 2500 MPa), and T g (> 90 °C) due to the introduction of rigid imine bonds, several aromatic groups, and the conjugated systems formed between imine bonds and benzene rings. Meanwhile, the incorporation of C N structure endowed ECANs with UV shielding properties. Based on the topology rearrangement induced by exchange reaction of imine bonds, ECANs exhibited excellent malleability with a stress relaxation time < 30 s at 120 °C. Thus, they showed reprocessability without sacrificing the mechanical and thermal performance. Moreover, biobased ECANs could be used as high-performance recoverable adhesives for aluminum with an original and recovered lap shear strength of > 53.9 MPa and > 40.0 MPa, respectively.
研究领域:
材料科学
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可持续发展
·
化学工程
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Feiyu Tang,BinWang,Jinpeng Li,Jun Xu,Jinsong Zeng,Wenhua Gao,Kefu Chen
There is an emerging quest for fabrication of water-soluble fluorescent silver nanoclusters (AgNCs) with long-lasting fluorescent properties and dimensional stability while being sustainable and functional. Thus, a well-known seed-mediated growth strategy has been developed to manufacture AgNCs supported onto carboxyl and aldehyde modified cellulose nanofiber (DATCNF) with ultra-small and intense fluorescence. The DATCNF acts as a reductant, template, and stabilizer while the protective ligand, 2-Mercaptonicotinic Acid (2-H 2 MA), provides AgNCs with luminous characteristic and constrained size of 4.47 nm. The structural feature of 2-H 2 MA also governs the formation and stability of AgNCs, imparting them with hydrophobic nature and steady fluorescence emission in water. This aqueous colloidal suspension (DATCNF-AgNCs) is highly dispersed, photobleaching resistant, and hardly agglomerates. Even after two months of exposure to the sun, the fluorescence intensity had only fallen by 20 %. Furthermore, the aqueous colloidal suspension exhibits outstanding antibacterial property and UV shielding capability, making it suitable as an additive for the production of TCNF films with high UV blocking capacity and high tensile strength. This strategy opens the door to design and fabricate mechanically robust DATCNF-AgNCs composites for luminescent, antimicrobial, and UV protection applications.
研究领域:
材料科学
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纳米技术
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生物医学工程
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产品关联
DOI
PubMed
高影响因子
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