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检测红茶产品中的合成色素对确保红茶的品质以及食用安全具有极其重要的作用。目前所能找到的文献仅对红茶本身所含的天然色素进行研究,没有对红茶产品中的合成着色剂的检测方法的研究。为了确保红茶产品的食用安全,开发适合红茶产品中合成着色剂的检测方法,笔者几年来做了大量实验,对传统食品中合成着色剂检测方法中的样品前处理方法进行改进和完善。实验数据表明,改进的步骤对红茶产品中的合成着色剂的提取有很好的效果,可成功检出阳性样品,为食品安全检测提供了重要的依据。 相似文献
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常伟林池俊杰刘建艇王建伟夏宇贾利亚邢校辉张晓勤 《化学推进剂与高分子材料》2016,(4):84-86
对N,N–二甲基叠氮乙基胺(DMAZ)的合成方法进行了分析,研究了反应溶剂、反应时间对产品合成的影响和高纯度产品的分离方法。开发了具有自主知识产权的"绿色环保"生产技术,该技术具有收率高、溶剂可循环使用、三废排放少及易于工业化等优点。 相似文献
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工艺参数对动态注塑成型制品品质的影响 总被引:2,自引:0,他引:2
采用聚丙烯(PP)材料,应用Taguchi DOE技术进行振动注塑成型正交实验,研究了工艺参数对制品成型收缩率和制品质量的影响。利用各振动频率段的较优参数组合,比较了振动条件下和稳态下的制品收缩率和制品质量。结果表明:制品的成型收缩率随着熔体温度的升高而降低,随着注射速率的增加而降低;制品质量随着熔体温度的升高而减小,随着注射速率的增大而增加;振动降低了制品成型收缩率,提高了制品质量。 相似文献
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Zinc-neutralized sulfonated EPDM ionomers (Zn-SEPDM) were prepared by batch and continuous melt sulfonation processes, and the ionomer products were compared with ionomers synthesized by sulfonation of EPDM in homogeneous solution. The efficiency of a batch melt sulfonation using an intensive mixer as a reactor was comparable to that of the solution sulfonation process, but the efficiency of the melt sulfonation in a twin-screw extruder was considerably lower, which was thought to be a consequence of a relatively short reaction residence time due to limitations of the equipment. Melt neutralization was not complete, which produced a dark colored product. However, the incomplete neutralization and the color of the product did not affect the mechanical properties of the melt sulfonated ionomers, which were comparable to those of ionomers made by conventional solution sulfonation. The metal sulfonate concentration alone determined the mechanical properties of the ionomer. Melt sulfonation of Zn-SEPDM ionomers by batch or continuous melt processes appears to be a practical alternative to solution sulfonation, but further optimization of the melt sulfonation processes is needed to ensure uniform sulfonation and complete neutralization. 相似文献
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在同向双螺杆挤出机上,对聚丙烯(PP)进行硅烷交联,制得高熔体强度聚丙烯(HMSPP),然后制备高发泡倍率的PP制品。分析了改性剂用量对PP熔体流动速率、熔体黏度、熔体强度、凝胶含量、力学性能、热性能和发泡性能的影响。结果表明:自制HMSPP的熔体强度和熔体黏度分别是纯PP的5.01倍和1.52倍,力学性能和耐热性与纯PP相比均有较大提高,可用于成型高发泡倍率制品。 相似文献
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将聚丙烯与1%的滑石粉混合造粒,使用N2作为物理发泡剂,通过自行搭建的非连续超临界N2注气系统,研究发泡注塑工艺过程中注射行程、注射速度、螺杆转速、熔体温度对制品表面质量、减重和泡孔结构的影响。结果表明:注射行程引起的熔体填充量变化是影响制品减重的首要因素,随着填充量的增加,减重下降明显;高压力降速率能够得到均匀泡孔分布且泡孔密度较高的制品;螺杆转速导致停留时间改变对制品表面质量影响较大;熔体温度影响到发泡剂在聚合物熔体中的溶解,螺杆转速130~150 r/min、熔体温度200℃时,能够得到减重、制品表面质量和泡孔结构俱佳的制品。 相似文献
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使用高长径比的接枝型反应挤出机,研究了在反应挤出过程中马来酸酐接枝无规共聚聚丙烯(PPR)(PPR-g- MAH)的熔融反应规律。研究反应单体马来酸酐(MAH)用量和过氧化二异丙苯(DCP)用量对产物PPR-g-MAH接枝率及熔体流动速率的影响。结果表明,最佳配方为MAH质量分数为2.0%,DCP质量分数为0.15%,此时产物的接枝率为0.55%,熔体流动速率为4.8g/10min。通过红外光谱、差示扫描量热仪(DSC)、广角X射线衍射仪(WAXD)分析表明,接枝物有明显的酐基吸收峰,表明PPR分子链确实接枝上强极性的酐基;接枝物的熔点与原料相同;晶型和结晶度基本没有发生改变。 相似文献
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A. J. van der Goot R. Hettema L. P. B. M. Janssen 《Polymer Engineering and Science》1997,37(3):511-518
This article describes the radical copolymerization of styrene (St) and n-butyl-methacrylate (BMA) in a counter-rotating twin-screw extruder. In order to investigate the effect of the polymer melt viscosity on the working domain in reactive extrusion, the copolymer was crosslinked with different amounts of divinylbenzene (DVB). Crosslinking of the polymer resulted in a higher polymer melt viscosity. It was demonstrated that not only the product properties but also the process characteristics were strongly influenced by the addition of divinylbenzene to the reaction mixture. The product properties changed as expected: more crosslink agent led to a higher molecular weight or an increase in gel fraction, and a much higher melt viscosity of the polymer. Besides these effects on the product properties, the addition of DVB resulted in a more stable process, leading to an enlarged working domain. 相似文献