INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
·
IF 4.784
Tao Zheng,Dingming Zhong,Dafeng Zheng,Fengli Bao,Jianmin Zheng,Xueqing Qiu
In order to develop a biomass-based superplasticizer, kraft lignin (KL) was grafted with isopentenol polyoxyethylene ether (TPEG) to prepare a novel macromonomer (KL-TPEG). It was shown that the retention ratio of the aliphatic C C bond increased from 81.07% to 90.20% with the increase of m(TPEG)/m(KL). When the grafting ratio was increased, the average number of TPEG grafted on one KL molecule was approximately 1.4, 3.1, 4.6, 6.2 and 7.6. The star-like structure was also confirmed by FT-IR, 1 H NMR and GPC. KL-TPEG had favorable surface activity and dispersion stability on the cement particles. It was illustrated that the shear stress and shear viscosity of the cement slurries with KL-TPEG were significantly less than that of blank slurry. The dispersion-retention ability of KL-TPEG on the slurry was also gradually enhanced with the increase of the grafting ratio of TPEG. It was seldom reported on the biomass-based TPEG. Through modified with KL, the rheology behavior and the dispersion-retention ability of TPEG was greatly improved, and the cost of TPEG was also reduced, thus this study not only promoted the development of biomass-based macromonomer, but also helped for the high value utilization of lignin.
研究领域:
材料科学
·
生物质化学
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产品关联
DOI
PubMed
高影响因子
POLYMER
·
2014
·
IF 3.766
Weichun Huang,Sheng Wang,Chengxin Guo,Xiaoming Yang,Yaowen Li,Yingfeng Tu
Two simple and effective methods, “click” chemistry and supramolecular interactions, are demonstrated here to synthesize well-defined poly( l -lactide) (PLLA) functionalized graphene oxide (GO) sheets. We provide a simple method to introduce azide groups on GO sheets by the ring opening reaction of sodium azide with the epoxide groups of GO. The GO-N 3 sheets can easily undergo “click” reaction with alkyne-terminated PLLA by “grafting onto” method to produce GO/PLLA composites with high grafting ratio and exfoliated structure. Interestingly, GO-N 3 can be grafted with oxygen-containing polymers such as PLLA, polymethyl methacrylate (PMMA) or polyethylene oxide (PEO) via supramolecular interactions between the azide groups and these oxygen atoms on polymers, producing GO/polymer composites with low grafting ratio and intercalated structure. These “grafting onto” methods are useful to produce a variety of GO/polymer composites with different structure via “click” reaction or supramolecular interactions, which have potential applications in material science.
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
POLYMER JOURNAL
·
2016
·Vol. 49
·期 2
·263-271
·
IF 1.629
Li Weiwei,Jiang Xue,Wu Ronglan,Wang Wei
We report a study on synthesizing fast, recoverable polyurethane/montmorillonite–poly(methyl methacrylate) (PU/MMT–PMMA) composites and understanding the influence of the grafting ratio of PMMA on the shape memory effect. PMMA was grafted on an exfoliated MMT surface via surface-initiated atom-transfer radical polymerization, which rendered a homogeneous dispersal of MMT in the PU matrix. The morphology and structure of the composites were characterized by scanning electron microscopy, transmission electron microscopy and powder X-ray diffraction. The mechanical, thermal and shape memory properties were characterized by dynamic mechanic analysis and temperature-modulated differential scanning calorimetry. Both tensile strength and strain at break for the composites increased with the introduction of MMT–PMMA, exhibiting 35 and 44% higher strength and strain than those of pure PU, respectively. The PU/MMT–PMMA composites showed high performance on shape memory behavior, with a shape fixity ratio of 100% and a shape recovery ratio of 99% in the first shape memory cycle. The composites also presented a higher shape recovery speed than both PU and PU/MMT. The best performance was obtained with a grafting ratio=3, with a recovery rate of 21.1° per second at 60 °C.
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
ACS Applied Bio Materials
·
2024
·
IF 4.6
Guohao Chen,Xiao Liu,Hui Liu,Shuhan Liang,Shuhong Sun,Miaomiao Han,Shengxiang Ji
Multidrug-resistant (MDR) Gram-negative bacteria infections have gradually become a more serious health problem recently, and antibacterial drugs are urgently needed to tackle MDR Gram-negative bacteria. Herein, we synthesized a series of quaternary ammonium salt derivatives of hyperbranched polylysine (HPL-Cm-n) with different alkyl chain lengths (m = 4, 8, 12, 16) and grafting ratios (n = 5.8–21.0) of alkyl quaternary ammonium salts (Cm). HPL-Cm-ns exhibited excellent antibacterial activities against drug-sensitive E. coli and P. aeruginosa, and specifically, HPL-C12-ns were also highly active against MDR E. coli and P. aeruginosa. The cytotoxicity and hemolytic activity of HPL-Cm-ns increased with the increase in the alkyl chain length and the grafting ratio of Cm. The killing study proved that HPL-C12-9.5 had fast killing kinetics and was bactericidal toward both drug-sensitive and MDR E. coli. The mechanistic studies showed that, similar to hyperbranched polylysine (HPL), HPL-C12-9.5 killed bacteria by disrupting the cell membranes and causing leakage of the cytoplasmic contents. HPL-C12-ns might have potential as an antibacterial agent to combat MDR Gram-negative bacteria.
研究领域:
药物化学
·
微生物学
·
材料科学
·
生物技术
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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）