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991.
992.
含乙酸木素复合型聚氨酯材料的合成及其性能研究 总被引:2,自引:0,他引:2
对以乙酸木素(AL)为原料合成复合聚氨酯材料的方法及其特性进行了研究和探索。对乙酸法制浆废液的木素进行了提取和纯化,并采用红外光谱和GPC研究了乙酸木素的结构和分子质量。以乙酸木素代替部分聚乙二醇合成了AL-TDI-PEG复合聚氨酯,并对其进行了拉伸强度、最大伸长率、DSC和TGA热性能的测定和红外光谱分析,而且也对木素用量和这些物理性能之问的规律进行了研究和探索。实验结果表明,木素-TDI-PEG复合PU片具有较好的拉伸强度、伸长率和耐热性。当木素用量为20%时,强度达到最大,而超过20%时,强度有所降低,说明乙酸木素的加入对PU的强度有一定的影响。 相似文献
993.
化工设备清洗技术进展 总被引:1,自引:0,他引:1
综述了化工设备污垢的形成机理及其清除方法.包括物理清洗和化学清洗等方法.介绍了一些新型清洗技术如微生物清洗、超声波清洗、激光清洗、在线清洗以及免清洗技术等.并展望了清洗技术的发展方向。 相似文献
995.
Luca Valentini 《Polymer》2005,46(17):6715-6718
The adsorption of several types of conducting polymers on carbon nanotubes is investigated by electrical transport measurements. We report the optoelectronic properties occurring in single-walled carbon nanotubes (SWNTs) conjugated polymer, poly(3-octylthiophene), composites. Al/polymer-nanotube composite/indium-tin oxide diodes show photovoltaic behavior proposing that the main reason for this increase is the photoinduced electron transfer at the polymer/nanotube interface. Interesting results were obtained in the case of poly(o-anisidine) (POAS)-multi-walled nanotubes (MWNTs) composites where the increment of monolayers results in a significant improvement of the specific conductivity. POAS-coated MWNTs thin films demonstrated their potentiality as a new class of materials for inorganic vapors detection for environmental applications. 相似文献
996.
New extensive data are reported for the solubility of carbon dioxide in fourteen physical solvents, and compared to two other solvents widely used in industry (selexol® and sulfolane). The solubility data are expressed by Henry's law constants and have been measured at 25 °C, 40 °C and 60 °C, using an Autoclave cell. The study concludes that polyethylene glycol dimethyl ethers, and mixtures of these solvents are the best solvents for CO2 removal. 相似文献
997.
Colin?WilbornEmail author Jacqueline?Beckham Bill?Campbell Travis?Harvey Melyn?Galbreath Paul?La Bounty Erika?Nassar Jennifer?Wismann Richard?Kreider 《Journal of the International Society of Sports Nutrition》2005,2(2):4-31
Obesity and its associated disorders are a growing epidemic across the world. Many genetic, physiological, and behavioral
factors play a role in the etiology of obesity. Diet and exercise are known to play a valuable role in the treatment and prevention
of obesity and associated disorders such as hypertension, heart disease, and diabetes. Therefore, the purpose of this review
is to examine the prevalence, etiology, consequences, and treatment of obesity. 相似文献
998.
999.
"立德树人"是高等教育的根本任务,思政教育能培养青年大学生树立正确的价值观.以近三年的《物理化学》课程教学实践为基础,举例说明《物理化学》课程的思政元素提炼,讨论了如何在授课教学环节有机融入课程思政内容.结果表明,思政元素的融入不仅能有效提高教学质量,更能激发学生的爱国热情,培养学生的辩证思维,有利于培养有理想、有素养... 相似文献
1000.
Maria Cristina Righetti Patrizia Cinelli Laura Aliotta Elisa Bianchi Fabio Tricoli Maurizia Seggiani Andrea Lazzeri 《Polymer International》2022,71(1):47-56
This paper reports the thermal, morphological and mechanical properties of environmentally friendly poly(3-hydroxybutyrate) (PHB)/poly(butylene succinate) (PBS) and PHB/poly[(butylene succinate)-co-(butylene adipate)] (PBSA) blends, prepared by melt mixing. The blends are known to be immiscible, as also confirmed by the thermodynamic analysis here presented. A detailed quantification of the crystalline and amorphous fractions was performed, in order to interpret the mechanical properties of the blends. As expected, the ductility increased with increasing PBS or PBSA amount, but in parallel the decrease in the elastic modulus appeared limited. Surprisingly, the elastic modulus was found properly described by the rule of mixtures in the whole composition range, thus attesting mechanical compatibility between the two blend components. This unusual behavior has been explained as due to co-continuous morphology, present in a wide composition range, but also at the same time as the result of shrinkage occurring during sequential crystallization of the two components, which can lead to physical adhesion between matrix and dispersed phase. For the first time, the elastic moduli of the crystalline and mobile amorphous fractions of PBS and PBSA and of the mobile amorphous fraction of PHB at ambient temperature have been estimated through a mechanical modelling approach. © 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry. 相似文献