有机氟硅共改性水性聚氨酯乳液的合成及其性能

将异佛尔酮二胺(IPDA)和甲基丙烯酸十二氟庚酯(DFMA)进行Micheal加成反应,合成端仲胺基的有机氟化合物(DFMA-IPDA)。以该化合物为扩链剂、聚醚改性聚二甲基硅氧烷(PDMS)为二元醇,与异佛尔酮二异氰酸酯(IPDI)、聚氧化丙烯二醇(PPG)、二羟甲基丙酸(DMPA)聚合制备了有机氟和硅改性的水性聚氨酯(WPU),研究了有机氟和/或硅用量对WPU乳液性能和胶膜性能的影响。结果表明:用该方法合成的DFMA-IPDA纯度达99.2%,和一定量的PDMS共改性可合成稳定的WPU乳液。随两者用量的增加,WPU乳液的平均粒径增大,胶膜的热稳定性、耐水性提高,表面水接触角增大。PDMS可提高WPU胶膜的柔性,而DFMA-IPDA可提高胶膜的韧性。用PDMS和DFMA-IPDA共改性能获得综合性能优异的WPU,当扩链剂完全采用DFMA-IPDA,PDMS用量为4%时,WPU胶膜的吸水率为4.5%,水接触角达到102.3°。     

不同封端结构聚二甲基硅氧烷改性水性聚氨酯研究

用4种不同封端结构的聚二甲基硅氧烷(PDMS)制备改性水性聚氨酯(WPU),研究了在软段中引入不同结构PDMS和不同Si(CH3)2O含量对WPU性能的影响。结果表明,羟基硅油PDMS1(Mn=1000)由于生成易水解的Si—O—C结构,与聚氨酯相容性最差,降低了WPU的透明度和光泽度。羟烷基封端的PDMS2(Mn=1000)与聚氨酯具有良好的相容性,能够明显地提高WPU的耐水性、光泽度和力学性能;羟烷基封端的PDMS3(Mn=2000)由于Si(CH3)2O链节长度和含量最大且在聚氨酯结构中分布较为集中,与聚氨酯相容性较差,使WPU的透光率和光泽度明显降低;羟基聚氧化乙烯亚丙基封端的PDMS4(Mn=2200)引入Si(CH3)2O链节含量最低,能赋予WPU较高的光泽,但聚醚链段的引入使其改性样品力学性能和硬度较差,耐水性低于其他3种。     

PDMS改性水性聚氨酯消光树脂的制备及性能

以聚四氢呋喃二醇(PTMG)、端羟丙基聚二甲基硅氧烷(PDMS)、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)为预聚物反应单体,三乙胺(TEA)为中和剂,乙二胺(EDA)为后扩链剂,制备了有机硅改性水性聚氨酯(WPU)消光树脂乳液及胶膜。采用FTIR、激光粒度分析仪(LPSA)、SEM、X射线色散能量谱仪(EDS)、60°光度计对样品的结构和性能进行了表征。考察了R值(反应原料中—NCO和—OH的物质的量比)、PDMS用量(用PTMG和PDMS的物质的量比来表示)对WPU胶膜光泽度的影响,测定了有机硅改性水性聚氨酯消光树脂的性能。结果表明,当R=2.3,n(PTMG)∶n(PDMS)=1∶2.0时,WPU乳液粒径为300.8 nm,SEM显示WPU胶膜表面形成致密的微米级球状凸起。此时WPU胶膜的综合性能最佳,60°光泽度达到最低值10.9,吸水率为23.0%。     

有机硅丙烯酸酯改性水性聚氨酯的合成与性能

以异佛尔酮二异氰酸酯(IPDI)、g-氨丙基三乙氧基硅烷(KH550)、甲基丙烯酸甲酯(MMA)、g-(甲基丙烯酰氧基)丙基三甲氧基硅烷(KH570)为原料,分别合成了水性聚氨酯预聚体(WPU)、聚丙烯酸酯(PA)、有机硅改性的水性聚氨酯预聚体(Si WPU)和有机硅改性的聚丙烯酸酯(Si PA),然后以WPU、SiWPU、PA、Si PA为原料,采用互穿网络聚合法合成了有机硅-丙烯酸酯双重改性水性聚氨酯。通过测定吸水率和水接触角考察了PA、Si PA、Si WPU含量对胶膜耐水性能的影响并分析了反应机理。结果表明:SiWPU-40%-SiPA-37.5%〔40%为Si WPU的含量(以WPU和SiWPU总质量为基准,下同);37.5%为Si PA占膜总质量百分数〕胶膜吸水率从改性前样品WPU的37.8%降低至改性后的6.8%,接触角从56.8°增至86.4°,铅笔硬度从改性前的2B提升至H。热重分析显示,T_(max)(样品热分解速率最大时的温度)从改性前的340.2℃提升至412.4℃;TEM表明,改性后的乳胶粒形成了核壳结构;XRD和断面SEM显示,PA和有机硅改性均增加了聚合物的交联度。     

交联剂种类对水性聚氨酯性能的影响

以异佛尔酮二异氰酸酯(IPDI),聚醚多元醇N210、N220为主要原料,分别采用聚醚三元醇N330,蓖麻油(C.O),三羟甲基丙烷(TMP),季戊四醇(PER)为交联剂,合成了一系列状态稳定的水性聚氨酯乳液,探讨了不同种类的交联剂对胶膜力学性能、胶膜耐水性以及耐热性能的影响。实验表明,用TMP交联改性的水性聚氨酯(WPU)胶膜力学性能和耐水性较为优异,用N330和C.O.交联改性的胶膜手感很好,耐热性能也较好,用PER交联改性的胶膜力学性能有所提高,但耐水性能和耐热性能较未改性前反而有所降低。     

羟烷基聚二甲基硅氧烷改性水性聚氨酯的制备及性能研究

以羟烷基封端聚二甲基硅氧烷(PDMS)、聚氧化丙烯二醇N220、异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)和1,4-丁二醇(BDO)为主要原料,制备了改性水性聚氨酯(WPU)乳液,研究了PDMS用量对其乳液性能、固化膜机械性能和表面性能的影响。结果表明,随PDMS用量的增加,WPU乳液粒径先增大后减小,而其粘度先降低后增加。PDMS改性WPU能明显改善固化膜的性能,增加PDMS的用量,固化膜的拉伸强度、硬度和耐水性及光泽度提高,透光度、耐热性和断裂伸长率降低。当软段中PDMS质量分数为20%时,WPU的综合性能最优,在光泽度、耐水、透光率和力学性能方面明显优于羟基硅油改性样品。     

有机硅改性磺酸/羧酸型水性聚氨酯的研究

以聚醚多元醇(N-210)和2,4-甲苯二异氰酸酯(TDI)为原料,以自制的磺酸型亲水单体1,2-二羟基-3-丙磺酸钠(DHPA)和二羟甲基丙酸(DMPA)为扩链剂,采用氨丙基三甲氧基硅烷和氨乙基氨丙基三甲氧基硅烷对纯水性聚氨酯(WPU)进行改性,并对有机硅改性WPU胶膜的性能进行了研究。结果表明:WPU分别经两种不同结构的有机硅改性后,其胶膜的力学性能略高于未改性WPU,但耐水性和耐热性则明显高于未改性WPU。     

羟基硅油改性水性聚氨酯的制备与性能研究

以羟基硅油（PDMS）、二苯基甲烷二异氰酸酯（MDI）、聚醚多元醇为主要原料,合成了有机硅改性的水性聚氨酯（WPU）材料,探讨了PDMS用量对WPU乳液和胶膜性能的影响,并采用FT—IR和DSC对其进行了表征。结果表明,随着PDMS加入量的增加,乳液粒径增大,粘度升高,胶膜的吸水率降低,力学性能和热稳定性提高。当PDMS质量分数为11．8％时,制备的有机硅改性聚氨酯材料性能最佳,其吸水率下降至5．6％,拉伸强度达到14．74MPa,断裂伸长率为462％,胶膜的初始分解温度提高了36℃。     

短链和长链交联剂对水性聚氨酯性能的影响

采用不同链长的交联剂三羟甲基丙烷(TMP)、蓖麻油(CTO)和改性蓖麻油(MCO),通过预聚体混合法合成了3种内交联的水性聚氨酯(WPU)分散液。借助激光粒度分析仪、电子拉力试验机和热失重分析详细研究了不同链长交联剂对WPU乳液和胶膜性能的影响。研究结果表明:TMP交联的WPU具有较小的平均粒径和较窄的粒度分布,其胶膜具有较好的力学性能和耐热性;CTO交联的WPU则具有较大的粒径和较宽的粒度分布,但其胶膜具有更好的耐水性;MCO交联的WPU胶膜具有更高的相混合程度和最高的吸水率。     

有机硅改性水性聚氨酯膜处理温度对性能的影响

采用聚四氢呋喃二醇(PTMG)和异佛尔酮二异氰酸酯(IPDI)为主要原料,端羟基聚二甲基硅氧烷(HTPDMS)为改性剂,通过改变HTPDMS的含量合成一系列改性的水性聚氨酯(WPU)乳液。乳液室温成膜后,在不同温度下进行热处理。采用核磁共振(NMR)测试、粒径测试、X射线光电子能谱(XPS)、耐水性能和力学性能等测试对样品进行了表征,考察了不同HTPDMS含量及不同后处理温度对WPU乳液及涂膜性能的影响。结果表明,Si元素在胶膜表面的显著富集,使胶膜耐水性能提高;随着乳胶膜后处理温度的升高,Si元素迁移能力明显提高,拉伸强度也明显提高。采用扫描电子显微镜观察了WPU膜的断面形貌,当HTPDMS引入到聚氨酯分子链中,聚氨酯基质出现了不同程度的相分离。     

关于逆流冷却塔雨区阻力计算的探讨

在逆流式冷却塔的空气阻力计算中,常常忽略了雨区阻力的计算,包括国标规范与高等教育的教科书等权威文献也未提及,根据工业塔的实测,这部分阻力占全塔空气阻力的1/6左右。本文根据冷却塔设计与运行的实践,并结合国内外学者对此的实验研究成果,经分析总结,给出了一个较为系统可行的计算方法,经验证与工业塔实测基本吻合,可供冷却塔设计中参考使用。     

耐高温尼龙聚邻苯二甲酰胺的研究进展

综述了聚邻苯二甲酰胺(PPA)的特性和应用,对部分PPA新品种制备方法及表征测试作了介绍,还介绍了PPA在耐热性、吸水性、尺寸稳定性、耐焊锡性等方面的研究进展。     

Improving the bending and corrosion resistance of an enamel by the addition of β-Si3N4 whiskers

Enamel–metal composite materials with high strength and corrosion resistance are often used for fabricating enameled pressure vessels for pharmaceutical and chemical production. However, the low bending resistance of the enamel can result in the cracking and delamination of the enamel layer, leading to the loss of corrosion resistance of the enameled pressure vessel, which can result in accidents. Here, based on the goal of increasing the bending resistance of the enamel to prolong its service life, the effect of β-Si₃N₄ whiskers on the mechanical properties of enamel was studied by three-point bending tests. The effect of β-Si₃N₄ whiskers on the acid and alkali corrosion resistance of enamel was studied using aqueous H₂SO₄ and NaOH solutions, respectively. A sudden change in the force of an enameled sample under the three-point bending test was used to evaluate the bending resistance of the enamel–metal samples, and can also be used to evaluate the mechanical properties of other comparable materials. With the addition of 0.5 wt% β-Si₃N₄ whiskers, the bending resistance was significantly improved, along with the acid and alkali corrosion resistance. These findings are expected to provide guidance for the design and production of enamel-metal vessels with improved performance that can significantly lengthen the service life of enameled pressure vessels and reduce the occurrence of accidents.     

电阻器专用涂料(Ⅰ)

介绍了电阻涂料底漆、面漆的种类和各类电阻涂料底漆和面漆的组成、特点及技术规格。同时,还简介了环氧型、油墨型及有机硅型标志涂料的特点和技术指标。     

Effect of partial substitution of alumina–chromium slag for Al2O3 on microstructures and properties of Al2O3–SiC–C trough castables

Alumina–chromium slag (ACS), a cheap and abundant refractory raw material comprising aluminum–chromium oxides and β-Al₂O₃, is a byproduct of ferrochrome smelting. For this reason, we investigated the relationships between composition and mechanical properties, abrasion resistance, oxidation resistance, and resistance to iron slag erosion for Al₂O₃–SiC–C trough castables in which ACS was substituted for alumina. Due to the presence of β-Al₂O₃ in ACS, the aluminum-chromium slag reacted with SiO₂ to form a low-melting phase of albite and promoted the formation of mullite, which filled the pores at high temperatures and reduced the porosity, thereby promoting densification and strengthening of the sample. The cold mechanical properties of the sample and the normal temperature wear resistance were enhanced, but the high-temperature mechanical properties and the resistance to iron slag corrosion of the sample were impaired. According to the results of the anti-oxidation experiment, the presence of β-Al₂O₃ in the ACS reduced the porosity and made the sample more dense, which remarkably improved oxidation resistance of the sample. For industrial production requirements, ACS substitution should not exceed 48?wt% due to of thermomechanical properties and anti-slag corrosion performance in Al₂O₃–SiC–C trough castables.     

Enhancement of thermal shock and slag corrosion resistance of MgO–ZrO2 ceramics by doping CeO2

The purpose of this paper was to develop ceramics materials with high thermal shock resistance and corrosion resistance for preparing gas blowing components. In this paper, MgO-rich MgO–ZrO₂ ceramics were obtained by using MgO powder and ZrO₂ powder as starting materials and CeO₂ as an additive. Changes in the properties in terms of thermal shock resistance, mechanical properties, and slag corrosion-resistance with chemical compositions were examined correlated to microstructure and phase changes. Especially, the effect of doping CeO₂ on phase transition of zirconia in MgO-rich system was discussed. The results showed that doping amount of CeO₂ significantly improved properties of MgO–ZrO₂ ceramics. Especially when doping amount of CeO₂ was 2 wt%, residual strength ratio was enhanced over 100% after thermal shock testing. In samples doped with CeO₂, ZrO₂ was stable in cubic or tetragonal form due to complete solution of CeO₂, which was important reason for the improvement of various properties of MgO–ZrO₂ ceramics.     

钢骨架塑料复合管的性能和应用

对钢骨架塑料复合管与其他管道的性能进行了比较,对比结果证明:钢骨架塑料复合管具有耐压、耐磨、耐腐蚀、抗蠕变、安装方便以及较高的性价比等特点。     

硅树脂及其涂料的研究新进展

综述了近十年来国内外耐热、耐腐蚀、耐候性硅树脂、改性硅树脂及其涂料的研究新进展；指出了硅树脂及其涂料的发展趋势。     

氧化镁-尖晶石浇注料的组成与性能的关系

以中档烧结镁砂、矾土基尖晶石和电熔白刚玉为主要原料,制备了不同基质组成的试样,并研究了浇注料的流动性、强度、永久线变化率、抗渣性和抗热震性。结果表明：基质的组成（特别是Ａｌ２Ｏ３／ＭｇＯ比）对浇注料的抗渣性、线变化率、抗剥落性和热震稳定性有显著影响,通过调整Ａｌ２Ｏ３／ＭｇＯ比可制得综合性能优良的氧化镁－尖晶石浇注料     

无醛防皱整理剂的研究进展

传统的防皱整理的发展历程及面临的新问题，阐述了多元羧酸类防皱整理剂作为棉织物理想的无甲醛防皱整理剂的防皱机理及性能，但由于它存在价格贵、织物泛黄色变、耐洗牢度差、含磷催化剂污染环境等问题，需要有效解决。最后，指出了无醛防皱整理今后的发展方向。