Synergistic flame retardancy of ZnO and piperazine pyrophosphate/melamine cyanurate in polypropylene

In order to improve the flame retardant efficiency and smoke-suppression of piperazine pyrophosphate/melamine cyanurate (PPAP/MCA) in PP, the synergism of ZnO and PPAP/MCA was investigated by limiting oxygen index (LOI) determination, UL-94 test, and cone calorimetry test (CCT). It is found that ZnO performs an exceptional synergism in flame retardant effect and inhibition on the flame propagation. Besides, ZnO can significantly inhibit the production of the smoke and CO. The TGA of the PP composites, the component and structure analysis of the heated composites and CCT residues reveal that ZnO performs the synergism primarily by the following modes: ZnO promotes obviously the charring of the composite, and improves the thermal stability as well as the strength of the intumescent layer, which brings about an improved flame retardant property and inhibiting ability on the flame propagation.     

大麻/黄麻交织物的焦磷酸钠与复合酶联合处理工艺

针对当前大麻/黄麻交织物粗糙刚硬,刺痒感明显及碱煮氯漂过程污染环境等问题,采用焦磷酸钠和复合酶(漆酶/酸性木聚糖酶复配)联合工艺对大麻/黄麻交织物进行处理,以织物质量减少率、织物断裂强力(经向)、弯曲长度、芯吸高度为指标进行单因子和正交优化试验,并进行了方差分析。得出最佳处理工艺方案:焦磷酸钠质量浓度为9 g/L,处理时间为90 min,处理温度为80 ℃,漆酶质量浓度为7.5 g/L,酸性木聚糖酶质量浓度为6.0 g/L,处理时间90 min,处理液pH值5.0。此时织物质量减少率为18.26%,织物断裂强力(经向)为780 N,织物弯曲长度较未经处理下降了24.82%,芯吸高度提高了46.4%,该工艺可达到碱煮氯漂(或碱氧一浴)效果,生态环保。     

汽车刹车片用改性酚醛树脂的生产

在原有的酚醛树脂生产设备上，用腰果壳油和三聚氰胺对酚醛树脂进行改性，制得的改性树脂具有较好的软化点、聚合速度、挥发度和游离酚等性能；并且热分解温度较普通酚醛树脂大大提高。用它作胶粘剂生产的汽车刹车片，冲击强度增大：磨损率降低、摩擦性能提高、产品成本也大为降低。     

Infrared characterization of the surface intermediates in the oxidation of toluene on vanadyl pyrophosphate catalysts

The adsorption and reaction of toluene on vanadyl pyrophosphate catalysts was studied by in situ infrared spectroscopy. Strongly adsorbed benzaldehyde and physically adsorbed cyclic anhydride species were observed at temperatures above 523 K. Water formed during reaction generates acid hydroxyl groups which cause a stronger adsorption of benzaldehyde and consecutive oxidation reactions. By co-adsorption of pyridine the acid sites are blocked and the deeper oxidation is suppressed. This revised version was published online in August 2006 with corrections to the Cover Date.     

三聚氰胺产需现状与发展

对国内外三聚氰胺的生产与消费现状、发展历史、生产工艺、产需能力分布等进行了分析,并对国内外市场进行预测。     

UHT产品三聚氰胺检测方法中前处理改进方法

研究TUHT产品三聚氰胺检测过程中前处理的检测方法,样品前处理利用透析纸或透析袋的热熔性和透析度,通过分子隔断筛选,使三聚氰胺分子自由穿入并溶于水中。此方法与国标方法比较：透析方法的前处理省时省事,并且所用消耗品较少,总体成本较现用方法便宜,但是在使用透析纸密封样品时必须小心包扎,不能漏样。     

Synthesis of the melamine-formaldehyde polycondensate and its thermal stabilization effect on polyoxymethylene

Melamine (MA) was polymeric modified by condensation reacting with formaldehyde (FA) to form the melamine formaldehyde polycondensate (abbreviation: MF) with high molecule-weight and comparatively high processing thermo-stability. The effect of the reacting molar ratio of MA and FA, and the types and concentrations of the dispersion agents on the structure and properties of MF were discussed, and the finely divided, cross-linked, and thermo-stable MF polycondensates were obtained. The thermal stabilization effect of MF on POM was studied by the isothermal weight loss analysis at 220 °C, isothermal weight loss rate analysis at 222 °C, thermal gravity analysis (TGA) and balance torque analysis, which showed that MF has almost the equal thermal stabilization on POM to MA. The multiple processing and long-term thermal stability at high temperature measurements indicated that MF showed even higher thermal stabilization on POM than MA. Moreover, the impact strength was improved after five times of extrusion, due to the better dispersion of MF in POM matrix and better nucleation effect of MF on POM.     

焦磷酸盐滚镀铜工艺研究与应用

为提高产品质量和生产效率,降低生产成本,研究开发了焦磷酸盐滚镀铜生产工艺,研究了镀液的组成及工艺条件对镀层性能的影响,确定了镀液配方及工艺务件。生产应用结果表明,焦磷酸盐滚镀铜工艺稳定,可明显提高产品质量和生产效率,解决了原镀铜工艺存在的问题,具有较好的经济效益和社会效益。     

焦磷酸盐低锡青铜合金电镀工艺及辅助配位剂的功能

为了提高焦磷酸铜．焦磷酸亚锡电镀低锡青铜合金工艺的性能,在其镀液中加入辅助配位剂柠檬酸盐。用电化学、X射线衍射、腐蚀膏试验等方法对镀液及镀层性能进行分析。结果表明：合金镀液具有良好的分散能力,可在较宽的电流密度范围内获得色泽一致、锡含量约为10％的低锡合金镀层;电镀初始过程可实现钢铁表面的电位活化,提高了镀层与铁基体的...     

ATR—IR和固体NMR法分析鉴别仿瓷餐具的材质

目前,市场上存在着用脲醛树脂代替密胺树脂为原料生产的仿瓷餐具。为有效地鉴别这2种不同原料的制品,本文采用衰减全反射红外（ATR—IR）和固体核磁共．撩（S-13CNMR）方法,分析市售的仿瓷餐具。ATR—IR实验结果表明：810cm^-1处为密胺餐具的特征峰,1630cm^-1处为脲醛餐具的特征峰。同时,S-13CNMR实验表明：δc159为脲醛中羰基的特征化学位移,δc166为密胺的氮杂环上碳的特征化学位移。2种方法均可以有效地对仿瓷餐具的材质进行分析鉴别,但前者实用性更强。