目前生物可降解塑料主要采用堆肥降解测定其生物降解性能的方法进行鉴别,其检测周期长、费用较高。材料的组成基本决定了其生物降解特性,为了快速鉴别生物可降解塑料,采用热裂解-气相色谱-质谱法(PY-GC-MS)对以聚对苯二甲酸-己二酸丁二醇酯(PBAT)与不同质量比的其他成分包括生物可降解聚乳酸(PLA)、难降解材料聚苯乙烯(PS)或聚对苯二甲酸乙二醇酯(PET)混合样的裂解特征进行了研究。结果显示,PBAT的裂解特征峰明显,未受到PLA的影响;若在PBAT中添加质量分数1%的非降解材质PS和PET也可被检出。方法用于市场上收集到的标识为可降解塑料购物袋样品的分析,结果表明,采用PY-GC-MS可以快速对可降解塑料进行初步鉴别。

Biodegradable platics were mainly identified by the method of compost degradation to determine their biodegradability, which had long detection cycle and high cost. The composition of the material basically determined its biodegradation characteristics. In order to identify quickly biodegradable materials, the pyrolysis characteristics of mixed samples of poly(butylene adipate-co-butylene terephthalate) (PBAT) and other components at different mass ratios, including biodegradable polylactic acid (PLA), and non-biodegradable material polystyrene (PS) or polyethylene terephthalate (PET), were studied by pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS). As shown by the results, the characteristic peak of PBAT decomposition was obvious and was not affected by PLA. If non-degradable materials PS and PET with 1% of mass fraction were added to PBAT, they could also be detected. This method was used for the analysis of samples of degradable plastic shopping bags collected in the market. It was shown that PY-GC-MS could be used for rapid preliminary identification of degradable plastics.