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制备了两种聚合型碳化二亚胺抗水解剂A和B,通过红外光谱、热重分析等对其进行了表征;并研究了抗水解剂A、抗水解剂B和市售单体型碳化二亚胺Stabaxol I对聚己二酸对苯二甲酸丁二醇共聚酯(PBAT)抗水解性能的影响。采用聚合型碳化二亚胺抗水解剂A和B改性的PBAT比采用Stabaxol I改性的PBAT具有更加优越的抗水解性能;添加质量分数0. 1%的聚合型碳化二亚胺的PBAT材料的抗水解性能与添加质量分数0. 6%Stabaxol I的PBAT材料的抗水解性能相当,同时抗水解剂A和B均能显著降低高熔体质量流动速率(MFR) PBAT的初始MFR。 相似文献
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聚氨酯胶粘剂水解问题的有效解决途径 总被引:1,自引:0,他引:1
聚合物有几种主要的降解机理:热降解、化学物降解、氧化降解、微生物降解以及水解降解。其中,水解是缩聚反应生成的聚合物最致命的弱点,聚氨酯粘合剂也不例外。水解使聚合物的力学性能在一段时间后丧失殆尽,严重影响了其使用性能和应用范围。碳化二亚胺(Stabaxol~(?))是为解决酯类聚合物水解问题而研制的高效抗水解剂。文章描述了碳化二亚胺抗水解剂在聚酯型聚氨酯粘合剂中的水解保护机理及效果。 相似文献
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混炼型聚氨酯橡胶的稳定性 总被引:1,自引:0,他引:1
高强度、高耐磨的聚氨酯橡胶一直是橡胶制品领域用途极大的一类品种,对其研究也在不断深入。针对聚酯型聚氨酯的抗水解问题和聚醚型透明聚氨酯的抗紫外、抗褪色问题进行了研究,指出分别将碳化二亚胺作为抗水解剂和将AO-10(或AO-15)、HALS-65、UV-28的组合作为抗紫外、抗褪色剂,能较好地解决上述两个问题。 相似文献
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合成纤维产业现状和未来发展方向 总被引:1,自引:0,他引:1
叙述了国内外合成纤维工业的发展现状,指出世界范围内正在展开的新一轮竞争的主要特点,合成纤维的生产和消费中心已转移至中国,中国合成纤维市场消费持续增长,未来受到制约。分析了合成纤维技术进步的主要进展状况,生产趋向于大型化和柔性化,品种开发向高新技术纤维领域发展。提出了未来符合可持续发展方向的生产工艺和产品品种。 相似文献
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我国聚氨酯工业现状和发展展望 总被引:13,自引:3,他引:13
概述了我国聚氨酯工业发展的历史和现状、国外聚氨酯工业发展趋势及对国内的影响,对国内聚氨酯产品的需求进行了预测。经初步行业调查表明,我国聚氨酯制品产量2000年已达92.2万t,2005年将达约150万 t。对异氰酸酯、聚醚多元醇、聚氨酯泡沫制品、弹性体制品、涂料、胶粘剂等聚氨酯分支领域在“十五”期间的发展趋势提出了详细的规划,并提出了一些措施和政策性建议。还对聚氨酯工业2015年的远景发展提出了设想。 相似文献
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概述了世界聚酰胺原料及其纤维的生产现状和发展趋势;世界己内酰胺的生产能力稳步增长,新增生产能力主要集中在亚洲,己二酸新增产能主要来自中国大陆,己二胺的生产主要集中在北美和西欧,世界聚酰胺纤维的增长主要源自于亚洲,正朝多功能、高性能、生物基等方面发展;我国己内酰胺生产能力和产量均保持两位数的年均增长率,己二酸的生产发展迅速,呈现供过于求,聚酰胺纤维生产主要集中在浙江省、江苏省、福建省;指出我国应加强聚酰胺纤维的改性研究,加快产业链及产品结构调整,实现聚酰胺纤维规模化及原料国产化生产,以促进我国聚酰胺纤维工业的持续稳步发展。 相似文献
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超临界水直接液化褐煤是高湿低阶褐煤高效转化与资源化利用的一个重要的发展方向。阐述了超临界水液化制油的优势,总结了液化过程中的热解反应、脱杂反应、缩聚反应等关键反应;重点论述了操作条件(温度、停留时间、压力、溶剂等)对反应过程的影响机理;针对油品质的升级,总结了催化剂在液化油升级中的应用,分析了煤本身所含的铁系催化剂的催化特点,总结了贵金属在催化升级中的研究现状及部分过渡金属合金的高效催化特性;强调了煤与生物质共同液化的协同作用。对液化过程中存在的问题进行了总结,并展望了未来的工业放大应用。 相似文献
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María F. Gayol Diana O. Labuckas José Aparicio Juan C. Oberti Nelson R. Grosso Carlos A. Guzmán 《Journal of the American Oil Chemists' Society》2009,86(1):65-70
The objective of the research was to characterize the quality of damaged and undamaged jojoba seeds. The study was performed
on jojoba seeds grown in La Rioja, Argentina. Proximal composition, fatty acid composition, acid value, peroxide value, conjugated
dienes and trienes and protein electrophoresis profiles were determined in undamaged (JS) and damaged jojoba seeds (DJS).
The fat content (wax) was lower in DJS (39.11%) than in JS (50.82%). The values of acid, peroxide, conjugated dienes and trienes
were higher in DJS than in JS. No difference in fatty acid composition was observed between DJS and JS. The protein content
was not significantly different between JS and DJS. However, DJS had lower soluble protein values. In the electrophoresis
profiles, the band located at 50 kDa disappeared in DJS and the intensity of the band located at 25 kDa decreased. The deterioration
process in jojoba kernels significantly affects the chemical quality of their proteins and waxes. 相似文献
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Abdorreza S. Mesgar Zahra Mohammadi Fariba Rasouli‐Disfani 《Journal of the American Ceramic Society》2017,100(10):4719-4733
The aim of this work was to develop bioactive chitosan scaffolds reinforced with monetite‐containing whisker‐like fibers. The fibers synthesized by homogeneous precipitation were characterized as monetite/hydroxyapatite short fibers (MAFs), using XRD, FTIR and SEM. The pure chitosan and MAFs/chitosan composite scaffolds were produced by freeze‐drying, and characterized with respect to porosity, pore size, swelling behavior, compressive strength and modulus, and in vitro bioactivity. The incorporation of MAFs in chitosan matrices led to increase the pore size, according to the evaluation by FE‐SEM, and decrease the porosity of composite scaffolds. The swelling ratio decreased as MAFs content of scaffolds increased. The compressive strength and modulus of scaffolds were improved by an increase in MAFs content. The noncross‐linked scaffolds with a chitosan: MAFs weight ratio of 1:1 (CW3) showed a porosity of 75.5%, and the strength and modulus of 259 kPa and 2.8 MPa in dry state, respectively. The crosslinking by glutaraldehyde resulted in improved mechanical properties. The strength and modulus of cross‐linked CW3 scaffolds in wet state reached to 345 kPa and 1.8 MPa, respectively. The in vitro bioactivity of the reinforced scaffolds, evaluated by FE‐SEM/EDS, XRD, and ATR‐FTIR, was confirmed by the formation of a carbonated apatite layer on their surfaces when they soaked in simulated body fluid (SBF). The results of this initial study indicate that the monetite‐containing whisker‐like fibers may be an appropriate reinforcement of chitosan scaffolds. 相似文献
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锦纶66微纤维活性染料染色条件探讨 总被引:3,自引:0,他引:3
采用毛用和棉用活性染料对锦纶66微纤维染色,详细讨论了染色温度、染浴pH值、染色和皂洗方法对染色深度和固色率的影响,分析了不同类型的活性染料对染色条件的敏感性。活性染料对锦纶66微纤维的染色深度、固着率和固着效率受温度、pH值、染料母体结构和活性基的影响很大。毛用活性染料更适合于锦纶66微纤维的染色,普通乙烯砜硫酸酯及乙烯砜硫酸酯/一氯均三嗪染料可有选择性地加以使用,毛用活性染料合适的染色pH值约为4,其它染料适用的pH值因品种而异。采用酸性染色或先酸性后碱性的染色条件均可,后者的优点是固着效率高,但染色深度未见提高染色后采用碱性条件皂洗有利于染色深度的提高。 相似文献
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Solids motion and holdup profiles in liquid fluidized beds 总被引:1,自引:0,他引:1
Non-invasive gamma rays-based techniques, computer tomography and computer-aided radioactive particle tracking, were used to measure solid holdup and solid velocity profiles in liquid-solid fluidized beds. The time averaged velocity measurements indicated that multiple circulation cells exist in the column. The solid motion was upward in the center and downward near the walls in the fully developed part of the column. The flow pattern is reversed in the entry region of the column. The solid holdup values increase slightly with the increase in radial position in the fully developed region. The average values of holdup in the column were in agreement with other measurements and with the modified Richardson-Zaki equation. The solids mean velocities and eddy diffusivities increase with increase in liquid superficial velocity, column size, particle size and density. Distributor-type affects the mean velocity and turbulence parameters while the column height has a relatively minor effect. The solids motion and turbulence parameters presented here are useful for validation of CFD models. 相似文献