JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 138
·期 42
·51242
·
IF 3.125
Weiduo Wang,Huayi Li,Qian Li,Zhi Luo
A novel phosphorous/benzene-containing flame-retardant diphenyl phosphoryl polyethylene (PEP) is synthesized from ethylene vinyl acetate (EVA) copolymer with two steps reactions and its chemical structure is characterized by Fourier transform infrared and nuclear magnetic resonance spectroscopies. The grafted molecular dispersion is calculated by gel permeation chromatography and the phase transition is analyzed by differential scanning calorimetry. And results show its promising processability potential. High density polyethylene (HDPE) composite containing 15 wt% PEP is prepared by melt blending, and its fire performance and thermal behaviors are investigated in terms of limiting oxygen index (LOI), vertical burning (UL-94) and thermogravimetric analysis. There is a 16% increase to 20.2 in the LOI value of PEP, while it fails the UL-94 test. The char morphology is characterized by scanning electronic microscopy and observed multi-layered intumescent residue char effectively reduces the transfer of heat and oxygen. The major degradation is quantitively analyzed by the Flynn-Wall-Ozawa method. The results demonstrate that there is a catalytic effect by the phosphorous substance in char formation. Finally, the mechanical properties tests show that the loss due to the addition is small, which signifies the good compatibility between the pure HDPE and the grafted addition.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 16
·6136-6145
·
IF 3.069
Tianlu Xu,Jinrui Zhang,Lijie Qu,Xueyan Dai,Peihong Li,Yanlong Sui,Chunling Zhang
A phenyl group was introduced into the polymeric network of polysiloxane foam for the improvement of its thermal insulation capacity and thermal stability. Phenyl-containing polysiloxane was prepared via ring-opening polymerization, and phenyl-containing polysiloxane foam was fabricated through simultaneous foaming and crosslinking reactions. With increasing phenyl content, the thermal conductivity of the polysiloxane foam decreased from 0.093 W m−1 K−1 to 0.079 W m−1 K−1. When the phenyl content was 6.15 mol%, the average cell diameter decreased from 384 μm to 165 μm and the cell density increased from 0.58 × 108 cells per cm3 to 4.67 × 108 cells per cm3. When the phenyl content was 8.5 mol%, the cell morphology became imperfect and the average cell diameter and cell density reached 259 μm and 1.29 × 108 cells per cm3, respectively. TGA results revealed the improved thermal stability of the polysiloxane foam. The TGA curves under nitrogen and air conditions could be divided into three stages. Under nitrogen conditions, the mass loss of the maximum decomposition stage decreased and the residue at 800 °C slightly increased. Under air conditions, the maximum decomposition temperatures of the three stages increased. The compressive strength and specific compressive strength were measured and showed a downward trend.
研究领域:
高分子材料科学
·
热功能材料
·
复合泡沫材料
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材料化学
·
绝缘材料工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 60
·34397-34407
·
IF 2.936
Meixi Feng,Chuanhai Gu,Chaoling Bao,Xiuqiong Chen,Huiqiong Yan,Zaifeng Shi,Xiaohong Liu,Qiang Lin
TiO2 nanoparticles (nano-TiO2) as one of the most extensively used nanoscale materials easily undergo spontaneous aggregation and gravity sedimentation ascribed to their high adsorption energy, which significantly restricts their actual applications. For this reason, a benzyl-grafted alginate derivative (BAD) with good colloidal interface activity, prepared by a bimolecular nucleophilic substitution (SN2) reaction, was used as the dispersant to stabilize nano-TiO2. The structure and colloidal properties of BAD was evaluated by FT-IR spectroscopy, 1H NMR spectroscopy, thermal gravimetric analysis (TGA) and dynamic light scattering (DLS). The effects of pH and ionic strength on the dispersion stability of BAD/nano-TiO2 suspensions were also examined by DLS. To further probe its feasibility as a drug delivery system, the BAD/nano-TiO2 complex was applied as particulate emulsifiers to fabricate drug-loaded Pickering emulsions. Meanwhile, the morphology properties and the sustained release performance of the drug-loaded Pickering emulsions were also investigated. Experimental results showed that the adsorption of BAD on nano-TiO2 was achieved by an intermolecular hydrogen bond between the carboxylic functional groups of BAD and the Ti–OH of TiO2. The adsorption of BAD enhanced the electrostatic repulsion and steric hindrance between nano-TiO2 improving the dispersion stability of nano-TiO2 at different pH and ionic strength. Additionally, the obtained Pickering emulsions displayed good drug-loading capacity and sustained release performance with the release mechanism of non-Fickian transport, which exhibited great potential in the pharmaceutical field.
研究领域:
材料科学
·
药剂学
·
界面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2021
·Vol. 31
·期 26
·2101143
·
IF 18.808
Shuang Xia,Yukun Chen,Jinfeng Tian,Jinfeng Shi,Chengzhen Geng,Huawei Zou,Mei Liang,Zhibo Li
Gecko-inspired microfibrillar adhesives have achieved great progress in microstructure design and adhesion improvement over the past two decades. Space applications nowadays show great interest in this material for the characteristics of reversible adhesion and universal van der Waals interactions. However, the impact of harsh environment of space on the performance of microfibrillar adhesives, especially the extreme low temperature, is rarely addressed. Herein, microfibrillar adhesives fabricated by phenyl containing polydimethylsiloxane (p-PDMS) elastomers with superior low-temperature reversible adhesion is proposed. p-PDMS elastomers are synthesized through one-pot anionic ring-opening copolymerization, and the resulting elastomers become non-crystallizable with excellent low-temperature elasticity. Low-temperature adhesion tests demonstrate that the adhesion strength of microfibrillar adhesives fabricated by p-PDMS elastomers can be well maintained to as low as −120 °C. In contrast, the adhesion strength of pure PDMS microfibrillar adhesive reduces more than 50% below its crystallization temperature. The low-temperature cyclic adhesion tests further demonstrate that p-PDMS microfibrillar adhesives exhibit superior reversible adhesion compared to that of PDMS microfibrillar adhesives, owing to the sustainable conformal contact and even distribution of loads over repeated cycles. This study provides a new fabrication strategy for microfibrillar adhesives, and is beneficial for the practical application of microfibrillar adhesives.
研究领域:
高分子材料学
·
仿生工程
·
低温物理学
·
航天器材料
·
界面科学
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 10
·1-9
·
IF 5.3
Yang Weiqiang,Fang Qiaoling,Lv Haiming,Zhang Guiyun,Ni Jiancong,Lin Zhenyu
A phenyl-modified silica isoporous membrane (Ph-SIM) was prepared on the indium-tin-oxide (ITO) electrode using the electrochemically assisted self-assembly (EASA) method. The resulting Ph-SIM preserved vertically ordered nanochannels while exhibiting outstanding hydrophobicity due to the incorporation of phenyl groups within the nanochannels. As a result, the Ph-SIM/ITO sensor exhibited a remarkable affinity for PCNB extraction through hydrophobic interactions, leading to high detection sensitivity. The electrochemical response showed a linear enhancement with the logarithmic concentration of PCNB ranging from 0.1 to 20.0 µM, and the limit of detection was 4.64 nM. Practical results demonstrated that the Ph-SIM/ITO sensor possessed good anti-fouling capability and robust stability, making it a promising candidate for portable detection of non-polar contaminants. Graphical Abstract
研究领域:
材料科学
·
分析化学
·
环境科学
·
电化学
✓ 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）