pH敏感型交联微球的制备

采用铈盐-羟基氧化还原引发体系,以对苯乙烯磺酸钠(SSS)和葡聚糖(Dex)为原料,通过自由基接枝聚合将聚对苯乙烯磺酸钠(PSSS)接枝到Dex上,得到接枝共聚物Dex-g-PSSS,再通过交联反应合成C(Dex-g-PSSS)微球。利用FTIR、光学显微镜、Zeta电位仪表征了试样的结构和形态,研究了反应条件对PSSS接枝度的影响,考察了C(Dex-g-PSSS)微球在模拟胃液和结肠液中的溶胀率。表征结果显示,C(Dex-g-PSSS)微球为交联微球,其Zeta电位为绝对值较大的负值。实验结果表明,在适宜的反应条件(硫酸铈铵浓度12 mmol/L、H+浓度0.08 mol/L、Dex 5 g、SSS 5 g、50℃,6 h)下,可得到接枝度为11.86 g(基于100 g Dex-g-PSSS)的PSSS。C(Dex-g-PSSS)微球有较明显的p H敏感性,它在模拟胃液中的溶胀率仅有134%,在模拟结肠液中的溶胀率可达到678%,是潜在的口服结肠定位给药系统基质材料。     

Polymerelektrolytmembranen für Hoch‐ und Niedertemperatur‐Brennstoffzellen aus strahlungsinduzierter Pfropfcopolymerisation

Radiation‐induced graft copolymerization of hydroxyethyl methacrylate with hydroxyethyl acrylate, acrylic acid or glycidyl methacrylate on ethylene tetrafluoroethylene (ETFE) films allow for tailor‐made synthesis of membranes for high and low temperature fuel cell applications. According to the operating temperatures proton conductivity may be achieved via doping with phosphoric acid or a two‐step sulfonation of the functional monomers. Fuel cell tests provide power densities and internal resistances, which indicate that the membranes are suitable for high and low temperature fuel cells.     

偕胺肟螯合树脂的合成研究及铀吸附性能测定

采用悬浮聚合的方法成功地合成了以二乙烯苯（DVB）交联丙烯腈（AN）共聚物为骨架的胺肟大孔螯合树脂。较详尽地研究了DVB－AN珠体胺肟化反应的影响因素：反应介质、反应比、反应温度、反应时间等，成功地制备了不同物理性能和不同单体组成的共聚物及胺肟螯合树脂，并且探讨了交联剂、致扎利、极性单体等因素对树脂的化学交换容量的影响。在本文描述的实验条件下，胺肟螯合树脂（干）的化学交换容量达到4．0mmol／g以上，经初步测定铀吸附性能取得了理想结果。     

悬浮态磁化焙烧菱铁矿及冷却条件对产品的影响

针对传统的堆积态菱铁矿焙烧工艺具有气固接触面积小、能耗大、矿石质量不均匀、容易产生"过烧"和"欠烧"的缺点,开展了悬浮态磁化焙烧细粒菱铁矿的试验,研究了不同冷却条件对焙烧产品的影响.研究结果表明,冷却速度是影响焙烧矿质量的重要因素,将焙烧矿在空气中快速冷却可跳过500～400℃相变激烈区,减小氧化程度,获得良好指标.     

微波辐射法在多糖接枝共聚中的应用

多糖是一种可用于合成高性能高分子材料的天然可再生资源,在自然界中蕴藏丰富。天然多糖接枝合成聚合物是制备多糖基材料的一种简便通用的方法。对目前天然多糖研究中存在的问题,接枝共聚的概念和目的,微波辐射法原理进行了介绍。同时对微波辐射法在壳聚糖、藻酸钠、纤维素、淀粉、黄原胶、瓜尔胶等多糖分子接枝中的实际应用进行了综述。     

超低密度聚乙烯的开发及应用

对在线型低密度聚乙烯(LLDPE)装置上开发生产的超低密度聚乙烯TJVL-1210的工艺参数、生产切换过程以及产品性能进行了分析。TJVL-1210采用两种α-烯烃与乙烯共聚合,使LLDPE密度从0.920 0 g/cm3降至0.912 0 g/cm3,突破了气相流化床反应器的生产技术瓶颈。TJVL-1210可应用于聚丙烯改性、热收缩膜、冷冻包装膜等领域,能够取代部分市场上的茂金属聚乙烯和聚烯烃弹性体等高端树脂。     

Suspension stability and sintering influence on yttria-stabilized zirconia fabricated by colloidal processing

The stability of nano-zirconia 3YSZ powder in suspension was extensively studied by the colloidal method, and the optimum sintering temperature of the green sample fabricated through slip casting was determined. Zirconia suspensions with 10 vol% powder loading were prepared with distilled water, and HNO₃ was used to adjust the pH of the suspension to pH 1–6. All of the suspensions were subjected to sedimentation test, and the results showed that the suspensions adjusted to pH 2 had the lowest sediment volume. This finding indicates that a suspension with pH 2 produces higher packing density. Viscosity test was carried out for the suspensions added with dispersant ranging from 0.3 wt% to 0.7 wt% polyethyleneimine (PEI) with and without pH adjustment. The suspension containing 0.5 wt% PEI with pH 2 adjustment produced the lowest viscosity because of interparticle bond breakage in the aggregates, thus forming colloidally stable suspensions. The zirconia suspension containing 0.5 wt% PEI and whose pH was adjusted to pH 2 was chosen to be slip casted into cylindrical shape. Green samples were sintered at various sintering temperatures that ranged from 1100 °C to 1500 °C through a two-step sintering method. The sample sintered at 1500 °C was found to be porosite-free, and its highest relative density was 99.6% of the theoretical density. Morphological studies detected pores in the microstructure of the samples sintered at low sintering temperatures (1100 and 1200 °C). By contrast, the samples sintered at 1400 and 1500 °C were fully densified. However, the grain size of the sample sintered at 1500 °C was 230 nm, which indicated excessive grain growth. The Vickers hardness of the sample sintered at 1400 °C was found to be highest (12.9 GPa) and comparable to results found in the literature.     

环氧树脂改性硅丙乳液的制备及水性涂料的研究

采用半连续单体滴加乳液聚合法制得稳定性好,凝胶率少,转化率高,综合性能良好的环氧树脂改性硅丙乳液。通过实验确定了所需的最佳条件,即阴离子与非离子乳化剂的最佳配比是2∶1,适宜温度78~80℃,引发剂的最佳用量0.7%,有机硅的最佳用量3%,环氧树脂最佳用量7%。并且以环氧树脂E-44改性硅丙乳液为主要成膜物质,制备了水性隔热防腐涂料。经检测,涂料的各项性能均满足国家技术标准。     

球形木质素珠体接枝丙烯腈的影响因素研究

利用反相悬浮聚合技术制备球形木质素珠体,再以Fe2＋/H202为引发体系,采用正交实验综合研究了球形木质素珠体与丙烯腈的接枝共聚反应的各种影响因素对珠体的接枝率和接枝效率的影响。结果表明：当m（单体）／m（基体）=10：1,反应时间为90min,反应温度55℃,Fe2＋浓度为0．03mmol／L,H202浓度为2．97mmol／L时,可以得到最佳的接枝率和较高的接枝效率,木质素一丙烯腈接枝共聚物的接枝率为780％,接枝效率可达76．0％。