Pyrolysis gas chromatographic-mass spectrometric identification of poly(dimethylsiloxane)s
Pyrolysis gas chromatographic-mass spectrometric identification of poly(dimethylsiloxane)s
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聚二甲基硅氧烷的热解气相色谱-质谱鉴定
DOI：
10.1021/ac50058a020
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
C. Weschler
中科院分区：
文献类型：
--
作者：
J. Kleinert;C. Weschler
聚二甲基硅氧烷的热解（980℃，1秒）产生一系列环状二甲基硅氧烷，使用气相色谱-质谱法对其进行分离和检测。通过选择性监测主要热解产物六甲基环三硅氧烷的质谱中 m/e 207、208 和 209 的离子同位素簇，可以定量分析痕量聚合物。论证了该技术在10'5至10～10 g范围内聚二甲基硅氧烷测定中的应用。随着流体粘度的增加，检测到的物质的量也增加，这将精度限制在大约一个数量级。然而，如果聚二甲基硅氧烷的粘度已知，该技术允许分析精确到 10% 以内。 1978 年生产了大约 2.35 亿磅有机硅 (1)，几乎是同年生产的尼龙量的十分之一 (2)。有机硅存在于多种产品中，包括合成润滑剂、油漆树脂、抛光剂、冷却剂、定影油、塑料、制动液、密封剂、表面活性剂和电介质。聚二甲基硅氧烷无疑是生产的最大一类有机硅。这些材料的表面张力较低，约为 17-22 达因/厘米，并且
Pyrolysis of polydimethylsiloxanes (980 C, 1 s) yields a series of cyclic dimethylslloxanesthat are separated and detected using gas chromatography-mass spectrometry. Trace amounts of polymer can be quantitatively analyzed by se-lectively monitoring the isotopic cluster of ions at m/e 207, 208, and 209 present in the mass spectrum of the major pyrolysis product, hexamethylcyclotrisiloxane. Application of this technique to polydlmethylsiloxane determination in the range from 10'5 to 10~ 10 g is demonstrated. The amount of detected materials increases as the viscosity of the fluid in-creases, and this limits accuracy to about an order of magnitude. However, if the viscosity of the polydlmethylsiloxane is known, the technique permits analyses accurate to within 10%.Approximately 235 million pounds of silicones were pro-duced in 1978 (1), almost one tenth the amount of nylon produced during the same year (2). Silicones are found in a vast array of products, including synthetic lubricants, paint resins, polishes, coolants, fuser oils, plastics, brake fluids, sealants, surfactants, and dielectrics. Polydimethylsiloxanes are easily the largest class of silicones produced. These ma-terials have low surface tensions, about 17-22 dynes/cm, and