Thermal degradation behaviors of polypropylene with novel silicon‐containing intumescent flame retardant

The N‐[3‐(dimethoxy‐methyl‐silanyl)‐propyl]‐N′‐ (9‐methyl‐3,9‐dioxo‐2,4,8,10‐tetraoxa‐3,9‐diphospha‐spiro[5.5]undec‐3‐yl)‐ethane‐1,2‐diamine/dimethoxy dimethyl silane copolymer (PSiN II), which simultaneously contains silicon, phosphorus, and nitrogen, is synthesized and incorporated into polypropylene (PP). The flame retardancy is evaluated by the limiting oxygen index value, which is enhanced to 29.5 from 17.4 with 20% total loading of PSiN II. The thermal degradation behavior of PP/PSiN II is investigated by thermogravimetric analysis under N₂ and air. The PP/PSiN II sample degrades at 400°C for different amounts of time, and the process of degradation is studied by Fourier transform IR. The morphology of the char formed at 400°C for 10 min is investigated by scanning electron microscopy. The swollen inner structure, close, and smooth outer surface provide a much better barrier for the transfer of heat and mass during fire and good flame retardancy. The thermal stability of PP is improved by incorporation of PSiN II. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2487–2492, 2005     

关于填充N115炭黑胎面胶热扩散系数的研究

对填充不同质量份N115发黑的轮胎胎面胶的热扩散系数进行了研究，实验误差小于3％。分析数据发现，胶料的热扩散系数均随温度的升高而减小，随N115发黑填充量的增加而增大。耙热扩散系数与温度和N115发黑填充质量份数进行关联，导出了一个既包含温度，又包含N115炭黑质量份数的关系式。把谈关系式的计算值与实验值进行比较后发现，总平均相对误兰为0．23％。最大相对误差为0．56％。     

磁场对CaCO3结晶过程的影响

本文利用电导率的变化,研究了磁场对CaCO3结晶过程的影响,发现当Ca^2＋浓度高于2mmol/L、磁化水的水温低于70℃时,磁场有加快碳酸钙结晶的作用;磁化水经过磁水器次数多,则促进碳酸钙结晶的作用强.     

掺纳米Al2O3的纳米ZrO2(4Y)固体电解质的电性能

以纳米ZrO2(4Y)粉和纳米Al2O3粉为原料, 单轴成型, 1 200, 1 300 ℃无压烧结. 对掺不同质量分数(0.0～5.0%)Al2O3的ZrO2(4Y)烧结体, 用XRD, SEM和TEM研究了相组成和微观结构. 在不同温度下(300～1 000 ℃)测试了交流阻抗谱, 发现掺很少量的纳米Al2O3可降低ZrO2(4Y)的晶粒电阻. 但随着Al2O3掺入量的增加, 晶界电阻增大, 晶粒电阻也有所回升. 晶粒和晶界电导活化能则随Al2O3掺入量的变化不大. 对1 200 ℃,2 h烧结样品, 在1 000 ℃时, 掺0.5% Al2O3的ZrO2(4Y)样品有最大电导率, 为3.8×10-2Ω-1·cm-1.     

阻燃硅橡胶的研制

通过测定硅橡胶试片的离火熄灭时间及燃烧速率来判定热硫化硅橡胶的阻燃性。结果表明，氢氧化铝对热硫化硅橡胶具有良好的阻燃效果；随着氢氧化铝用量的增加，硅橡胶的物理机械性能下降。通过对氢氧化铝进行表面处理，并与氯铂酸等阻燃剂配合，可制得符合美国UL-94V-0阻燃标准的硅橡胶制品。在本实验条件下的最佳配比为：100份混炼硅橡胶，45份氢氧化铝，50份氯铂酸(以铂质量计／10^-6)，2份乙炔炭黑及铁锡复合氧化物，制品拉伸强度大于5MPa。     

Synthesis of Thermally Stable χ-Alumina by Thermal Decomposition of Aluminum Isopropoxide in Toluene

Thermal decomposition of aluminum isopropoxide in toluene at 315°C resulted in χ-alumina that had high thermal stability, whereas the reaction at lower temperatures resulted in formation of an amorphous product. The χ-alumina thus obtained directly transformed to α-alumina at ∼1150°C, bypassing the other transition alumina phases, whereas the amorphous product transformed to γ-alumina and then to θ-alumina before final transformation to α-alumina. When the χ-alumina, solvothermally synthesized at 315°C, was recovered by the removal of the solvent at the reaction temperature, thermal stability of the product was improved further. This procedure is convenient because it avoids bothersome work-up processes that yield large-surface-area and large-pore-volume alumina.     

再生高含盐水景观河道生态修复工程水质净化效果

通过对天津经济技术开发区泰达再生高盐水景观河道生态修复工程实际水体水质变化情况进行研究，分析了滨海盐碱地区高盐再生水景观河道水体生态修复工程的水质净化效果以及河道盐份动态变化规律。研究结果表明：水体中主要污染物COD浓度在54．15～94．15mg／L范围内变化，几乎没有去除；氖磷净化效果非常明显，它们的最大去除率分别为TN69．35％、NH3-N50．75％、NO3^--N71．89％、TP56．97％、po^3-4-p81．02％；河道水体全盐量（TDS）浓度在4300～5200mg／L范围内波动，TDS浓度有所升高，增加量不大，只有850mg／L左右，表明洗盐基本结束。由此说明生态修复工程对泰达再生高盐水景观河道水环境质量改善效果明显。     

Study of stability of high‐temperature polyimides using TG/MS technique

The oxidative stability of the carbon fiber‐reinforced composite of polyimide was examined, in real time, using the evolved gas analysis techniques. Off‐gas degradation products suggested the onset temperature for chain scissions to be fairly low at about 190–220°C. Based on the off‐gas products present and the trend of their release, the composite degradation mechanism appeared to be similar between 190 and 371°C, thereby marking 371°C to be the highest accelerated aging temperature for its long‐term lifetime prediction. Beyond 371°C, different degradation mechanisms would apply. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1219–1227, 2002     

水泥基复合材料纳米化改性的研究

水泥基材料中70％为纳米尺度的C—S—H凝胶,因此对水泥基材料进行纳米改性具有很好的基础,我国有一些关于纳米基材料在混凝土中应用的研究,但目前还不可能在实体工程中采用这种混凝土。纳米在水泥科技中的应用应首先是纳米技术与一些技术含量高的水泥基复合材料的结合。研制具有超高性能(力学)以及特定功能的纳米水泥基复合材料是目前水泥基材料纳米化改性的研究方向。     

煤矸石热活化及相变分析

系统研究了不同温度下热处理活化煤矸石的物相组成和活性组分溶出的变化规律.用差热分析、X射线衍射、红外光谱、核磁共振、电感耦合等离子原子发射光谱和扫描电镜等仪器测试分析煤矸石原矿和不同煅烧温度制备的样品的矿物组成、分子结构、29Si和27Al化学位移、活性Si4 和Al3 溶出量及微观结构.结果表明:煤矸石的活化程度随不同温度下矿物相组成及铝配位情况的变化而改变.连续性的相转变与活性硅、铝的溶出量相对应.