磺化聚苯硫醚砜的制备和性能表征

以浓硫酸为溶剂,发烟硫酸为磺化剂对聚苯硫醚砜的磺化过程,通过改变温度、反应时间、浓硫酸的用量和发烟硫酸的用量这四个因素来探究磺化反应的条件。利用FTIR、热重分析(TGA)、磺化度、比浓黏度和溶解性测试对其结构和性能进行了表征。结果表明,采用磺化时间为2 h,反应温度15℃,浓硫酸8 mL,发烟硫酸与聚苯硫醚砜的质量比为9.5时,可得到磺化度为62.2%,比浓黏度为0.964 mL/g的磺化聚苯硫醚砜。磺酸基的主要分解温度为346℃,主链的分解温度为534℃。其溶解性得到提高,可溶解在介电常数大于20.7的有机溶剂中。     

磺化聚醚砜质子交换膜的制备及性能研究

以浓硫酸为溶剂、氯磺酸为磺化剂对聚醚砜（PES）进行了磺化，采用氢核磁共振谱（^1H NMR）、傅立叶变换红外光谱（FTIR）及热重分析（TGA）对磺化聚醚砜（SPES）进行了表征，证实PES得到了磺化。制备了一系列不同磺化度的SPES膜，测试了膜的接触角、含水率和电导率。试验结果表明，SPES具有良好的热稳定性；随着磺化度的增加，膜的亲水性能增加，膜的电导率增加。当SPES膜的磺化度达到37．0％（摩尔分数）时，SPES膜在室温下的电导率与商业化的Nafion 112膜的电导率相当。     

聚醚砜的磺化与热性能

以浓硫酸为溶剂 ,氯磺酸为磺化剂对聚醚砜 (PES)进行了磺化 ,制备了不同磺化度的磺化聚醚砜 (SPES)。探讨了反应的影响因素 ,分析了 SPES的热稳定性。结果表明 SPES的 Tg较 PES升高 ,随着磺化度的增加 ,SPES的降解温度降低。     

磺化聚砜/黑磷复合质子交换膜制备及性能研究

以聚醚砜(PES)为原料，采用氯磺酸(CSA)为磺化剂，通过控制反应温度和时间制备系列磺化聚砜(SPES)，并以SPES为基质，二维黑磷(BP)为功能填料，采用溶液铸膜法制备了复合质子交换膜。采用红外光谱分析仪(FTIR)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)等对材料结构进行表征，研究了复合膜的吸水率、质子交换性、阻醇性等。结果表明，SPES的磺化度随反应温度、时间、磺化剂浓度的升高而增大。BP的添加增强了复合膜的热稳定性、氧化稳定性、质子交换性、阻醇性等综合性能。在相同测试条件下SPES基膜的甲醇渗透率为1.185×10^-6 cm²/s，而5%(质量分数，下同)SPES/BP复合膜的甲醇渗透率仅为2.88×10^-7 cm²/s。     

3,3'-二磺化-4,4'-二氟二苯砜二钠盐的合成与表征

以工业级4,4'-二氟二苯砜(DFDPS)为原料,利用升华方法进行纯化处理后,采用发烟硫酸直接磺化,通过改变反应物计量比、反应温度、反应时间等参数,系统研究了3,3'-二磺化-4,4'-二氟二苯砜二钠盐(SDFDPS)的制备方法.采用HPLC、UV、~1H NMR 及FTIR对磺化产物结构及纯度进行了表征,由此得到最佳的磺化条件为:反应物摩尔比(SO_3∶DFDPS)为3.0∶1,在110℃下反应20 h.在此反应条件下的磺化产物中未发现单磺化产物以及未磺化的原料DFDPS.经过乙醇/水两次重结晶后,总收率达到75%.以合成的SDFDPS为原料合成了磺化度60%的磺化聚芳醚砜聚合物,该聚合物具有较高的相对黏度,同样也表明了SDFDPS的高纯度.     

磺化聚醚砜纳滤膜性能研究

本文主要研究了磺化聚醚砜 (SPES)复合纳滤膜的性能。详细讨论了纳滤膜对不同溶质的分离特性 ;探讨了无机盐浓度 ,操作压力 ,溶液 p H值及磺化聚醚砜的离子交换容量(IEC)与膜性能的关系 ;并对纳滤膜的电性能进行了初步研究。研究结果表明 ,磺化聚醚砜复合纳滤膜为一荷负电性纳滤膜 ,对无机盐有较好的选择分离性能。磺化聚醚砜的离子交换容量 ,无机盐浓度以及操作压力对膜性能影响较大 ,且对于两性溶质 ,膜的脱除性能与溶液 p H值有关     

磺化聚苯醚质子交换膜的制备与性能研究

以氯磺酸为磺化剂制备了一系列不同磺化度的磺化聚苯醚(SPPO)膜,通过热重-红外联用分析、差示扫描量热分析、含水率测试、力学性能和电导率测试,探讨了SPPO膜作为质子交换膜用于燃料电池的可能性。结果表明,SPPO存在3个阶段的失重,分别归属于吸收的水分、磺酸基团及主链的降解,磺化之后热稳定性虽有所下降,但主链的降解温度基本保持不变,玻璃化转变温度明显升高;SPPO的含水率随着磺化度和温度的增加而增加;膜的拉伸强度则随着磺化度的增加而降低,且膜在湿态时的强度较干态时的要低,但与商业化的Nafion 112膜相比仍具有较高的强度;磺化度为40.1%的SPPO膜在室温下的电导率为1.16×10-2S/cm,与Nafion 112膜为同一数量级。     

磺化PS及其离聚物的合成及性能研究

用乙酸硫酸作为磺化试剂合成了一系列低磺化度磺化聚苯乙烯(SPS),并将其离子化得到锌、镧离聚物。考察了反应温度、磺化试剂用量对磺化反应的影响。同时通过溶解测试、热分析、红外光谱法研究了系列SPS及其离聚物的溶解性、玻璃化转变温度(t_g)值、热稳定性及吸水性。实验表明:随着反应温度的提高及磺化试剂用量的增加,产物磺化度有不同程度的增加;随磺化度提高,产物在非极性溶剂中溶解性下降,t_g值增大,吸水性提高,离聚物比相应磺化物具有更好的热稳定性。     

3,3′-二磺化-4,4′-二氟二苯砜二钠盐的合成与表征

以工业级4,4′-二氟二苯砜(DFDPS)为原料,利用升华方法进行纯化处理后,采用发烟硫酸直接磺化,通过改变反应物计量比、反应温度、反应时间等参数,系统研究了3,3′-二磺化-4,4′-二氟二苯砜二钠盐(SDFDPS)的制备方法。采用HPLC、UV、¹H NMR 及FTIR对磺化产物结构及纯度进行了表征,由此得到最佳的磺化条件为：反应物摩尔比(SO₃∶DFDPS)为3.0∶1,在110℃下反应20 h。在此反应条件下的磺化产物中未发现单磺化产物以及未磺化的原料DFDPS。经过乙醇/水两次重结晶后,总收率达到75%。以合成的SDFDPS为原料合成了磺化度60%的磺化聚芳醚砜聚合物,该聚合物具有较高的相对黏度,同样也表明了SDFDPS的高纯度。     

磺化聚苯并咪唑/磺化聚醚砜酸碱复合质子交换膜的制备与表征

为提高膜的尺寸稳定性和阻醇性能,以磺化聚苯并咪唑(S-PBI)与高磺化度聚醚砜(ABPS)两种聚合物为原料,采用溶液共混的方法,制备了系列酸碱复合质子交换膜。研究了复合膜的甲醇溶胀性、吸水率、甲醇渗透系数、质子传导率随S-PBI含量的变化规律。研究表明,随着S-PBI含量的增加,膜的阻醇性能和尺寸稳定性明显提高;同时,复合膜具有较好的质子传导率,有望应用于直接甲醇燃料电池。     

喷气燃料储存安定性的研究

对喷气燃料的储存安定性进行了探讨,对喷气燃料的氧化机理进行了详细的研究,对常用抗氧剂进行了对比,对喷气燃料的颜色安定性及蒸发损失进行了阐述,并对未来进行了展望。     

Modification of melt,light, and heat stability of polyamide 6 by hindered piperidine amine and tertiary amine

Hindered piperidine amine (HPA) and tertiary amine (TA) were introduced into hydrolytic polymerization of caprolactam, and polyamide 6 (PA 6) modified by additives [HPA/TA = 1 : 1 (w/w)] was obtained. The effects of additives on the melt, light, and heat stability of PA 6 were studied. The results showed that with an increase in additive content, the viscosity of PA 6 increased and the elastic response decreased. Thus, the drawing property of PA 6 fibers during melt spinning was improved. With the addition of 0.1%–0.2% additives, the degree of variation in amino end group content and relative viscosity decreased during the process going from resin to fiber, indicating the modified PA 6 had improved melt stability. During light and heat aging, the ratio of retained fracture strength of PA 6 filament increased after modification by 0.1%–0.4% additives. Scanning electron microscopy showed that the surface morphology of the modified fiber remained almost the same, whereas that of the unmodified fiber was seriously destroyed when exposed to xenon light for 8 days or heated to 180°C in air for 1.5 h. The degree of variation of relative viscosity of the PA 6 fiber also decreased after modification by 0.1%–0.2% additives under oxidative degradation. All these results indicate PA 6 had better melt, light, and heat stability when modified by additives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 538–544, 2007     

矿山电力系统电压稳定分析

分析了矿山供电系统的特点,对电压稳定性、系统的稳定裕度及防止发生电压稳定破坏的措施进行了阐述。     

荧光纤维的特性研究

以湿法成型制得荧光薄膜、熔融纺丝制得荧光纤维为样品,研究了荧光粉含量、凝固浴和拉伸倍数对荧光强度的影响,并对荧光牢度(耐光性)进行了研究,还从耐洗涤、耐高温、耐溶剂、耐酸碱四方面对其性能稳定性进行了研究。     

一种测定乳状液稳定性的简便有效的新方法

An innovational test method was developed on the basis of redefinition of the emulsion stability. The stability was characterized by relative volume percentage of disperse phase demulsified thoroughly from the top part and the bottom part of an emulsion sample, each weighting the same amount, after being settled for a given time at constant temperature. Three series of emulsions were prepared and tested successfully, which were emulsions of paraffin oil and water stabilized with polyoxyethylene lauryl ether series (AEO3 and AEO9) at various HLBs,and emulsions of rapeseed oil and water stablized with sorbitan monoleate (Span80) and each of polyoxyethylene(20) sorbitan carboxylic esters (Tween20, Tween40, Tween60, Tween80 and Tween85) at different HLBs. It proved that this method is especially workable while the boundaries are opaque in a wide range of HLBs and is capable of offering an accurate optimum HLB.     

Improved thermal stability and luminescence properties of SrSi2O2N2:Eu2+ green phosphor by a heterogeneous precipitation protocol for solid-state lighting applications

The SrSi₂O₂N₂:Eu²⁺ green-emitting phosphor, as a member of oxynitride phosphors, could greatly enhance the color quality of the white-light conversed by single yellow-emitting phosphor. However, SrSi₂O₂N₂:Eu²⁺ phosphors prepared by traditional solid-state ways normally consist hard agglomerates with unevenly dispersed particles and therefore suppress the luminescence properties. This research proposes a heterogeneous precipitation protocol where precipitation process is introduced, in order to produce a precursor in the first phase. And in the second phase, a high-temperature solid-state process is adopted for obtaining the final product. The main results show that, for an optimized SrSi₂O₂N₂:Eu²⁺ phosphor prepared using our protocol, (1) the SrSi₂O₂N₂:Eu²⁺ particles are faceted and with smooth faces and (2) the phosphor photoluminescence, external quantum efficiency, stability against thermal exposure, and physical stability consistently outperform the current commercially used product. This research essentially provides an economic way for production of solid-state lighting with enhanced color quality.     

不同碱介质对合成硅基MCM-41的影响

研究了在较高的硅与表面活性剂摩尔比(10)体系中,采用不同的碱介质(氨水、乙二胺、三乙醇胺／NaOH)来合成MCM-41。通过XRD,N2吸附-脱附等表征手段,分析了不同碱介质体系对制备MCM-41的影响,并分别与NaOH介质中合成的MCM-41进行比较。结果显示,弱碱介质(NH3,EDA)有利于提高MCM-41的热稳定性;而采用混合碱介质(三乙醇胺／NaOH),则可在一定程度上改善MCM-41的水热稳定性,但随着三乙醇胺量的增加,材料的孔径会相应的减小。     

新型非对称聚酰亚胺的合成与性能研究

通过对4,4’-双(N-甲基联苯酰亚胺)的单硝化反应、亲核取代反应、水解反应和闭环脱水反应,成功合成了2-邻甲基苯氧基4,4’,5,5’-联苯四甲酸二酐。将这种新型非对称酸酐与4,4’-二氨基二苯醚和对苯二胺进行高温聚合反应制得了非对称聚酰亚胺。聚酰亚胺的特性黏度分别为0.55dL/g和0.89dL/g,它们在有机溶剂中的溶解性能较好,同时具有优良的热稳定性和热氧稳定性。     

Stability of sodium hypochlorite in the presence of aqueous flavoring essence

The stability of NaOCl in the presence of aqueous flavoring essences (lemon, mint, osmanthus flowers, pineapple, and vanilla) at 40±1°C was studied. Data from determination of OCl⁻ showed: (i) The stability of NaOCl solution decreased in the presence of essences in the order: mint> lemon and osmanthus flowers>pineapple>vanilla (P<0.01); (ii) OCl⁻ loss with the addition of lemon after incubation for 15 d was significantly greater in solutions with initial pH of 13.50 compared with those initially at pH 12.50 (P<0.01); and (iii) OCl⁻ loss was not significantly influenced by the difference in initial pH value with or without the addition of other essences.     

PTT树脂热分解稳定性研究

研究了不同相对分子质量PTT树脂在氮气和空气 2种气氛中的热分解稳定性。结果表明 ,在氮气中 ,PTT树脂只有 1个热失重台阶 ,相对分子质量对于PTT热分解参数影响不大 ,相应的热分解温度分别为θdi为 3 82 .2～ 3 83℃ ,θmax为 3 99.3～40 3 .4℃ ,θdf为 418.1～ 419.0℃ ,总失重为 88.4%～ 88.7% ,这可以作为PTT热分解稳定性的表征。在空气中 ,PTT树脂存在2个热失重台阶 ,在第 1失重台阶中 ,θdi为 3 70 .9～ 3 75 .2℃ ,θmax为 40 3 .9～ 40 5 .5℃ ,θdf为 414 .7～ 416.0℃ ,样品的总失重为88.9%～ 89.8% ,可以作为PTT热氧化分解稳定性的表征 ;而在第 2失重台阶中 ,θdi为 461.8～ 472 .2℃ ,θmax为 473 .9～ 487.8℃ ,θdf为 480 .5～ 494.1℃ ,样品的总失重为 8.6%～ 9.7% ,第 2失重台阶是残留物进一步氧化燃烧过程的体现。在 2 60℃下 ,PTT在氮气和空气气氛中受热 60min后分别有 1.4%和 4.8%的热失重。说明PTT的热氧化分解稳定性较其热分解稳定性要差 ,但两者相差不大。