Pfäffli P, Zitting A, Vainio H
Scand J Work Environ Health. 1978;4 Suppl 2:22-7.
Polystyrene without additional compounds was treated in a laboratory oven at elevated temperatures (200 degrees, 350 degrees, 500 degrees C) under slight air flow (0.7 l/min). The thermal degradation products appearing in different phases (gases, vapors, aerosols) were collected and analyzed by methods of chromatography. Thermogravimetric analysis showed the thermal degradation of the polymer to begin at 270 degrees C in air and stop at 425 degrees C. The main groups of vaporized compounds generated were monoalkyl-substituted aromatic hydrocarbons and their oxidized products, of which styrene monomer and benzaldehyde were the most abundant. Only trace amounts of carbon monoxide and aliphatic compounds (hydrocarbons, aldehydes, and acids) were produced. The aerosol produced, the amount of which increased as the temperature rose, contained mainly fragments of the polymer chain (e.g., dimers and trimers of styrene). The traces of styrene, cumene, and ethylbenzene that appeared at 200 degrees could represent residual compounds in the initial polymer and indicate the beginning of the thermal degradation. If proportional concentrations are kept as a criterion, the important products, from the point of view of industrial hygiene, were styrene, benzaldehyde, styrene oxide, acetophenone, and l-phenylethanol. The large amount of aerosol that appeared may also be of practical importance.
不含其他化合物的聚苯乙烯在实验室烘箱中于高温（200℃、350℃、500℃）及轻微气流（0.7升/分钟）条件下进行处理。收集不同阶段（气体、蒸汽、气溶胶）出现的热降解产物，并通过色谱法进行分析。热重分析表明，该聚合物在空气中于270℃开始热降解，并在425℃停止。产生的主要汽化化合物组为单烷基取代芳烃及其氧化产物，其中苯乙烯单体和苯甲醛含量最高。仅产生痕量的一氧化碳和脂肪族化合物（烃类、醛类和酸类）。产生的气溶胶量随温度升高而增加，主要包含聚合物链片段（如苯乙烯二聚体和三聚体）。在200℃出现的痕量苯乙烯、异丙苯和乙苯可能代表初始聚合物中的残留化合物，并表明热降解的开始。若以比例浓度为标准，从工业卫生角度来看，重要产物为苯乙烯、苯甲醛、氧化苯乙烯、苯乙酮和1-苯乙醇。出现的大量气溶胶也可能具有实际重要性。
