JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 35
·
IF 1.866
Yuanzhu Long,Fuhua Sun,Chao Liu,Dong Huang,Xingyi Xie
To explore a new blowing agent for polyurethanes (PUs), palmitic acid was grafted onto a branched polyethyleneimine (bPEI; weight-average molecular weight = 25,000 Da) via N,N ′-carbonyldiimidazole condensation to form a hydrophobically modified bPEI [palmitic acid grafted branched polyethyleneimine (C 16 –bPEI)] with a grafting rate of 12%. A CO 2 adduct of C 16 –bPEI, which trapped 16.8% CO 2 in it, was synthesized from C 16 –bPEI. The long alkyl chain grafting improved the dispersibility of the CO 2 adduct in the PU raw materials and favored a homogeneous release of CO 2 to blow PUs during the exothermic foaming process. The preliminary results show that the foams possessed a density of 72.0 kg/m 3 and a compressive strength of 246 kPa; this matched the required values of foams for the thermal insulation of underground steel pipes. This new blowing agent emitted nothing but CO 2 to the atmosphere, so it will not promote ozone depletion and will avoid global warming problems that are associated with traditional blowing agents such as chlorofluorocarbons and hydrochloroflourocarbons. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43874.
研究领域:
高分子化学
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材料科学
·
绿色化学
·
能源与环境材料
·
工业催化
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 23
·52314
·
IF 3.057
Xiangrong Chen,Zelin Hong,Chao Dai,Muhammad Awais,Fan-Bo Meng,Ashish Paramane,Hao Li
This paper investigates the influence of voltage stabilizer and nanofiller addition on the insulation performance of the cross-linked polyethylene (XLPE). The test samples of XLPE/stabilizer blends consisting of 1 wt% m-aminobenzoic acid, XLPE nanocomposites consisting of 0.5 wt% nano MgO and XLPE hybrid composite consisting of both voltage stabilizer and nanofillers were prepared. Various physicochemical and electrical properties were measured to analyze the performance of prepared samples. The obtained results show that the addition of nanofillers deteriorates the electrical insulation performance of the XLPE. On the other hand, the voltage stabilizer addition proves to be suitable for enhancing the electrical insulation performance of the XLPE. Meanwhile, the hybrid XLPE composites have shown medium behavior. The voltage stabilizer addition reduces, but the nanofillers increase the space charge density inside the XLPE compared to pure XLPE. It is also found that the dispersion of the voltage stabilizer in the material is uniform, whereas the nanofillers are aggregated. Furthermore, both additives slightly improve the thermal stability of the XLPE. The trap level theory based on quantum chemical calculation is proposed to explain the influence mechanism of the additives on the XLPE.
研究领域:
高分子材料科学
·
电气工程
·
绝缘材料
·
介电物理
·
材料化学
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聚合物纳米复合材料
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 133
·期 1
·
IF 1.768
Yao Zhou,Jinliang He,Jun Hu,Bin Dang
Polypropylene (PP)/polyolefin elastomer (POE) blends and MgO/PP/POE nanocomposites were fabricated by melt blending. The morphology, mechanical, and electrical properties of the nanocomposites were investigated. Scanning electron microscopy showed that the surface-modified MgO nanoparticles were well dispersed in the polymer matrix at low loadings of less than 3 phr. X-ray diffraction demonstrated that the crystalline phases of PP in the composites were changed and that the β phase significantly increased. An examination of the electrical properties revealed that the direct-current (dc) electric breakdown strength and space-charge suppression effect were remarkably improved by the introduction of the surface-modified MgO nanoparticles. In addition, obvious enhancements in the tensile modulus and strength were obtained as a result of the synergistic toughening of the POE and MgO nanoparticles. Thus, MgO/PP/POE nanocomposites with enhanced mechanical and electrical properties have great potential to be used as recyclable insulation materials for high-voltage dc cables with large transmission capacities and high operating temperatures. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132 , 42863.
研究领域:
高分子材料科学
·
电气工程材料
·
纳米复合材料
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介电物理
·
绝缘材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 86
·45930-45938
·
IF 3.708
Mengmeng Zhang,Hongxia Yan,Xiaowei Yang,Chao Liu
In this paper, graphene oxide (GO) was functionalized with a hyperbranched cyclotriphosphazene polymer, which was synthesized by the repeated reactions of hexachlorotriphosphazene with hexamethylenediamine. Subsequently, the resultant functionalized GO was incorporated into dicyclopentadiene bisphenol dicyanate ester (DCPDCE) to prepare composites. Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron spectroscopy were employed to examine the surface functionalization of GO. The effects of functionalized GO on the curing reactivity, mechanical, dielectric, thermal and water resistent properties of DCPDCE resin were investigated systematically. Results show that the addition of modified GO can facilitate the curing reaction of DCPDCE. Meanwhile, the appropriate content of modified GO can enhance the mechanical properties including impact and flexural strengths of DCPDCE resin. When modified GO content is 0.6 wt%, the corresponding composite exhibits slightly higher dielectric constant but lower dielectric loss than pure DCPDCE resin over the testing frequency from 10 to 60 MHz. In addition, the thermal stability and moisture resistance of modified GO/DCPDCE nanocomposties are also superior to that of pure DCPDCE resin.
研究领域:
高分子化学
·
复合材料科学
·
材料物理与化学
·
纳米材料
·
绝缘材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）