基于变活化能模型的T800/环氧树脂预浸料固化反应动力学研究

为了深入了解某新型高温固化T800/环氧树脂预浸料的固化行为,借助差示扫描量热仪(DSC),采用非等温DSC法研究了T800/环氧树脂预浸料的固化反应过程。基于唯象模型,系统研究了该预浸料的固化反应特征温度及固化动力学参数,确定该预浸料中环氧树脂的固化反应动力学模型为自催化模型。采用等转化率法,分析了预浸料中环氧树脂的反应活化能随固化度的变化情况,结果表明在整个固化反应过程中,树脂固化反应活化能变化较大,传统模型法基于全固化过程活化能不变的假设无法准确描述该固化反应。采用变活化能自催化模型,利用粒子群全局优化算法,得到了T800/环氧树脂预浸料的固化动力学方程,结果表明该模型能较好地描述实验现象,可为进一步研究该预浸料的热力学性能及其成型过程中的质量控制提供理论基础。     

中温固化碳纤维／环氧复合材料研究

本文详细介绍了中温固化的ＥＭ环氧基体及其复合材料的性能,固化工艺及应用情况,对ＥＭ环氧体系在湿法预浸料制造过程中的“现象进行了分析探讨。研究了５９４硼巡固化剂在丙酮中的溶解性,筛选出了助溶剂,解决了湿法预浸料制作时５９４固化剂在丙酮中的溶解发白现象。     

中温固化环氧树脂基体研究进展

阐述了在降低复合材料成本和提高复合材料性能方面,中温固化环氧树脂基体研制的重要性和必要性.根据用途的不同,从预浸料和湿法成型两个方面综述了中温固化环氧树脂基体的研究概况,并设想了该类基体在未来可能的研制途径.     

热固性碳纤维预浸料用环氧类基体树脂

综述了碳纤维预浸料用环氧树脂体系,介绍了国内外环氧树脂及其固化体系的发展现状;从碳纤维预浸料对基体树脂的要求,对环氧树脂固化体系的选择以及如何在树脂调配工艺上防止环氧树脂的爆聚等几个方面进行了详细的概述。     

环氧树脂/玻璃纤维模压预浸料固化反应动力学研究

采用非等温DSC方法研究了一种模压预浸料（环氧树脂/玻璃纤维）的固化动力学,应用Kissinger和Crane方程拟合求得固化动力学参数,并建立了该预浸料固化动力学唯象模型。通过无转子硫化仪测试预浸料在不同温度下的凝胶时间,通过线性拟合得到固化温度与凝胶时间的函数关系,并对预浸料的固化工艺进行优化。结果表明,通过Kissinger和Crane方法算得该预浸料的固化反应动力学表观活化能为89.9 kJ/mol,指前因子为1.17×10¹¹ min^-1,反应级数为0.93;预浸料在模具温度为150 ℃下预热40 s,环氧树脂具有一定的流动性,并在2 MPa压力下固化300 s,可制备综合性能良好的复合材料制品。     

预浸料用中温固化环氧树脂体系的研究

对一种中温固化并适用于热熔法制备预浸料的环氧树脂体系进行了研究。主要介绍了该树脂体系的工艺性能、贮存性能,并通过DSC和IR探讨了双氰胺固化环氧的固化机理。结果表明,当双氰胺和取代脲比例为6∶3时,预浸料用环氧树脂能实现中温固化,且在室温时有较长贮存期。     

一种无色透明环氧树脂复合材料的制备及其性能研究

本文选择适合无色透明环氧树脂/酸酐树脂的促进剂,对无色透明环氧树脂体系的流变性、凝胶时间、热性能等进行分析,确定了树脂的固化工艺。采用热熔胶膜法制备玻璃布预浸料,用模压法制备层合板,对预浸料和复合材料的物理性能、力学性能、耐热性和透光率进行测试,结果表明,无色透明环氧树脂预浸料在135℃/2h完全固化,复合材料层压板力学性能耐热性和透光率较好。     

一种OOA成型中温固化环氧树脂芳纶纤维预浸料研究

研制一种OOA(非热压罐)成型中温固化环氧树脂芳纶纤维预浸料,对树脂进行流变性能和DSC分析,确定树脂的固化工艺。采用热熔法制备OOA成型芳纶纤维预浸料,通过真空袋法成型复合材料层压板,进行性能测试。结果表明,OOA成型中温固化环氧树脂芳纶纤维预浸料适合真空袋法成型复合材料,层压板孔隙率低,力学性能满足要求,复合材料玻璃化转变温度高,具有较好的耐热性。     

混杂纤维复合材料性能研究

对碳纤维织物、玻璃纤维织物和芳纶织物的性能进行测试,采用热熔法分别制备了一种增韧中温固化环氧碳纤维织物预浸料、玻璃纤维织物预浸料和芳纶织物预浸料。预浸料以单种预浸料铺层和不同纤维织物预浸料混合铺层方式铺贴组合,通过模压法成型复合材料层合板,进行性能测试并对比。结果表明,增韧中温固化环氧树脂的不同纤维织物预浸料混合铺层成型的层压板力学性能可以根据铺层设计优化,并不损失不同纤维铺层之间的界面性能。     

碳纤维预浸料用中温固化环氧树脂体系

针对碳纤维预浸料常用环氧树脂体系的一些基本特点,以常温下为固体状态的环氧树脂混合物为基体,采用双氰胺为中温固化剂的固化体系,研究了双氰胺固化剂用量对环氧树脂体系黏度、力学性能、热学性能、溶胀性能的影响,对碳纤维预浸料用环氧树脂体系的研发及应用具有一定参考意义。     

Preparation of a high-temperature-resistant lightening agent and its application in a cement slurry system

With an organic–inorganic polymer lightening material (EL) based on epoxy resin and an aromatic amine curing agent, through addition reaction, we synthesized an epoxy-cured resin coupled with an inorganic activation filler, microsilicon. First, epoxy resin bisphenol A 2-glycidyl ether (E-51) and the curing agent, m-phenylenediamine, were selected as the materials for the epoxy-curing system. The thermal stability of the epoxy-cured compound (EM) was studied by differential scanning calorimetry and thermogravimetric analysis. The glass-transition temperature (T _g) of EM reached 131 °C, and the results show that T _g and the thermal stability was raised when EM was kept at 150 °C for 12 h. Second, the inorganic active filler was modified with a titanate coupling agent and characterized by contact angle measurement and Fourier transform infrared spectroscopy, and the results show that the titanate coupling agent was successfully applied to the modification of the inorganic active filler. Finally, the performance of EL in a cement slurry system was also studied. The macroscopic data showed that the compressive strength of the cement stone increased from 8.6 MPa for the EM cement stone system to 13.2 MPa for the EL cement stone system. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 136, 47292.     

循环水系统中特种粘泥菌的有效控制

扬子化工厂对苯二甲酸（PTA）的生产过程中时常发生严重泄漏，导致循环冷却水系统中产生大量难以杀灭的特种粘泥菌。我们研制了一种新型微生物生长调节剂（WB－1EM），较好地控制了粘泥菌的生长繁殖，达到了理想的处理效果。WB－1EM的成功应用对发生类似情况的厂家也具有很好的指导意义及借鉴价值。     

Microemulsion of erythromycine for transdermal drug delivery

The aim of this work was to prepare an erythromycin (EM) microemulsion (EM‐ microemulsion) for transdermal EM delivery using isotropic mixtures of oil and aqueous phases. The prepared EM‐microemulsion is a white dispersion, with a suitable viscosity for transdermal delivery. In stability experiments, the EM‐microemulsion showed no marked change in appearance for up to 3 weeks at 25°C. In accelerated stability experiments at 37 and 60°C, however, precipitated crystalline EM particles were observed in the EM‐microemulsion. Diffusion of EM into the skin exhibited a first order release profile. Fluorescein (FL)‐microemulsion penetrated to the dermis layer of skin. In conclusion, we confirmed that EM‐microemulsion could serve as an excellent transdermal carrier of EM. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

EM菌剂对河道污水的去除效果研究

为了寻求一种快速有效的黑臭河道水质净化技术,以新圳河水作为试验对象,考察EM菌剂对河道污水的净化效果。通过投加不同浓度的菌液,考察曝气对去除效果的影响。研究结果表明:投加EM菌剂后会降低水中DO浓度;投加EM菌剂22 d后,对CODCr、NH3-N、TN、TP的最大去除率分别达到52.4%、42.6%、41.6%、22.1%;曝气条件有助于提高CODCr的去除率;增加菌剂投加量有助于提高CODCr和NH3-N的去除率。EM菌剂对河道污水具有较好的净化效果。     

Synthesis of LiMn2O4 from a gelled ovalbumin matrix

A simple and inexpensive route for the preparation of LiMn₂O₄ using ovalbumin (egg white) as a gelating agent is described. Gelation of freshly extracted ovalbumin was effected by changes in ionic strength brought about by the addition of nitrate precursors to an aqueous solution of ovalbumin and subsequent warming. This resulted in tiny pockets of precursor materials getting trapped in the matrix of the gelled ovalbumin. Heat treatment of the gelled mass yielded submicron-sized LiMn₂O₄ crystals at temperatures as low as 400 °C.     

EM菌液在活性污泥系统中的实验研究

有效微生物应用于活性污泥系统中,分别进行了EM复壮、EM投加及EM絮凝性能的研究。研究表明：用糖蜜、蜂蜜及高浓度污水均能有效的复壮EM;在活性污泥系统中投EM液,可以提高系统的处理效率;EM复活液具有一定的生物絮凝性能。     

道康宁润滑系在轮胎硫化中的应用及改进

介绍了采用ＤＣ３２８９润滑系作为隔离剂和脱模剂在轮胎硫化中的应用及改进情况。在双模定型硫化机硫化中，采用ＤＣ３２８９润滑系作为隔离剂，选择合理的催化剂ＤＣ６２用量及涂刷方法，可以解决钢模结垢问题。在硫化罐硫化中，采用ＤＣ３２８９稀释液作为隔离剂，可以彻底消除“白粉”现象，提高轮胎外观质量，大大降低成本。在这两种硫化方式中采用ＤＣ３２８９润滑系，可以减少圈弯损伤和胎体变形等副次品，具有明显的经济效益和社会效益。     

循环水水质恶化的原因分析及对策

对循环水系统水质恶化的原因进行分析,发现含硫含氨等排污水进入循环水系统后,若采用二氧化氯杀菌剂作主剂,则杀菌效果较差,并且药剂消耗量大,投加时间长,余氯很难合格,最终因杀菌效果差,导致微生物繁殖,水质恶化,水耗偏高,浊度不易控制。     

表面活性剂在纳米氧化铅粉体合成中的应用

在PbAc4与Na2CO3反应体系中，加入表面活性剂（SAA）作为胶团分散剂，实验结果表明：随SAA质量分数增大，产物四氧化三铅（Pb3O4）粒径逐渐变小，当SAA质量分数达到一定（临界下限）值时，就可以得到纳米级Pb3O4；当SAA质量分数达到一定（监界上限）值时，Pb3O4粒度不再变小。复配表面活性剂质量分数下限为3．0％、上限为5．2％时，红丹粒径最小，平均粒度25nm，为单分散球形粒子。非离子表面活性剂质量分数下限为4．1％、上限5．2％，可得到片状纳米Pb3O4粒子。阴离子表面活性质量分数下限3．1％，上限5．2％，纳米Pb3O4粒子为串珠状。     

Interface evolution of a C/ZnO absorption agent annealed at elevated temperature for tunable electromagnetic properties

Excellent electromagnetic (EM) wave absorption agents that attenuate EM waves by mechanisms based on impedance matching, conductive loss and polarization loss instead of destructive interference are urgently needed but remain challenging. Here, an EM wave absorption agent with a tailorable heterogeneous interface is designed and prepared by the in situ growth of ZnO nanoparticles on the surface of mesoporous carbon hollow microspheres (PCHMs@ZnO) via hydrothermal synthesis followed by annealing. A controlled interface evolution associated with abundant heterogeneous interfaces plays a crucial role in optimized impedance matching and enhanced interfacial polarization loss. With this method, targeted EM wave absorption agents with an excellent absorption ability that is derived mainly from polarization loss and conductive loss rather than destructive interference are successfully obtained. When the PCHMs@ZnO annealed at 700°C were combined with paraffin, the effective absorption bandwidth of the resultant composites covers the whole X band, and the mean value of reflection loss (RL) reaches −12 dB, exceeding those of other reported ZnO-based materials. When the thickness of the composites varies from 3.3 to 4.3 mm, the value of the RL is lower than −8 dB in the whole X band. This work provides a promising model for preparing high-performance EM wave absorption agents.