共查询到11条相似文献,搜索用时 68 毫秒
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考察了4种增刚成核剂对抗冲共聚聚丙烯性能的影响,分析了成核剂用量对中熔体流动速率(MFR)高抗冲聚丙烯力学性能的影响,确定了最佳成核剂用量.结果表明:随着成核剂用量的增加,抗冲共聚聚丙烯的冲击强度稍有降低,刚性逐渐提高,随后趋于平缓.工业化应用后,成核剂的加入使产品的弯曲模量提高了约28%,拉伸屈服应力、结晶度及熔融结... 相似文献
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为改善山梨醇类成核剂在使用过程中分散性差、增透效率有限等缺点,将六种硬脂酸盐(锂、钠、钾、钙、锌、铝)作为润滑剂与山梨醇类成核剂复配协同改性聚丙烯(PP)。通过万能试验机、冲击试验机、熔体流动速率仪和雾度仪等设备对试样的光学性能、力学性能和流动性能进行表征。通过扫描电子显微镜(SEM)、偏光显微镜(POM)对改性PP的球晶形态和结晶形貌进行表征。结果表明:与硬脂酸锂、硬脂酸钠和硬脂酸钾相比,硬脂酸钙、硬脂酸锌和硬脂酸铝对PP的增透效果更好。硬脂酸钙、硬脂酸锌和硬脂酸铝在低含量下(≤0.03%),PP的光学性能、力学性能和流动性得到明显改善。硬脂酸钙、硬脂酸锌和硬脂酸铝的加入可以提升山梨醇类成核剂在PP基体中的分散性,从而提高PP的综合性能。 相似文献
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研究了HBP系列成核剂对聚丙烯性能的影响,并与NA-21成核剂进行了比较。结果表明,对于均聚聚丙烯,HBP-32,HBP-33成核剂具有较好的增刚和增透作用,其效果与NA-21成核剂相当;对于共聚聚丙烯,HBP-34成核剂具有优异的增刚效果,明显好于成核剂NA-21,HBP-32和HBP-33的。 相似文献
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钻井液增黏剂的反相乳液制备及性能评价 总被引:1,自引:0,他引:1
以丙烯酰胺和丙烯酸为共聚单体,过硫酸铵-亚硫酸氢钠为氧化还原引发体系,Span 60/Tween 80为复合乳化剂,在白油中进行反相乳液聚合,制备出了稳定的“油包水”型乳液,并初步评价了其在不同的钻井液中的性能.结果表明:该乳液在淡水、盐水以及饱和盐水钻井液中随着质量分数的增加具有较明显的增黏性能,但其在高温下的老化性... 相似文献
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Rumyana Simeonova Mariyana Atanasova Georgi Stavrakov Irena Philipova Irini Doytchinova 《International journal of molecular sciences》2022,23(23)
Oxidative stress is an essential factor in the development and progression of Alzheimer’s disease (AD). An excessive amount of reactive oxygen species (ROS) induces the peroxidation of lipid membranes, reduces the activity of antioxidant enzymes and causes neurotoxicity. In this study, we investigated the antioxidant and cholinesterase inhibitory potential of a novel galantamine–curcumin hybrid, named 4b, administered orally in two doses (2.5 mg/kg and 5 mg/kg) in scopolamine (SC)-induced neurotoxicity in mice. To evaluate the effects of 4b, we used galantamine (GAL) (3 mg/kg) and curcumin (CCN) (25 mg/kg) as positive controls. Ex vivo experiments on mouse brains showed that the higher dose of 4b (5 mg/kg) increased reduced glutathione (GSH) levels by 46%, catalase (CAT) and superoxide dismutase (SOD) activity by 57%, and glutathione peroxidase (GPx) activity by 108%, compared with the SC-treated group. At the same time, 4b (5 mg/kg) significantly reduced the brain malondialdehyde (MDA) level by 31% and acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities by 40% and 30%, respectively, relative to the SC-impaired group. The results showed that 4b acted as an antioxidant agent and brain protector, making it promising for further experimental research in the field of neurodegenerative diseases. 相似文献