回收利用聚酯醇解废液降解PET聚酯研究

Study on the degradation of PET polyester by using the waste polyester alcoholysis liquid

采用减压蒸馏法处理乙二醇降解PET聚酯所产生的废液,并将处理后的废液用于再降解PET聚酯,通过红外光谱(FT-IR)对回收废液降解聚酯所得产物的结构进行表征;用热重分析(TG)和差示扫描量热法(DSC)测定降解产物的熔点和热稳定性;并通过酸值羟值测定和质谱(MS)分析对降解产物的平均分子量进行表征。结果表明:回收废液降解聚酯所得产物的主要成分是对苯二甲酸二乙二醇酯(BHET),还含有少量的二聚体和对苯二甲酸聚乙二醇酯,平均分子量为267g/mol,产物产率为82.40%。

The vacuum distillation was used to process waste liquid which was from glycol degradation of the waste polyester（PET）,and the processed waste liquid was used for re-degradation of polyester.Characterization of the recovered product from waste liquid was investigated through infrared spectroscopy（FT-IR）.The melting point and thermal stability of degradation product were measured by thermogravimetry analysis（TG）and differential scanning calorimetry（DSC）.The average molecular weight of product were characterized by measuring the acid value as well as hydroxyl mass spectrometry（MS）analysis.The results showed that the recovered product from waste liquid had a major component of ethylene glycol terephthalate（BHET）,a minor amount of dimer acid and polyethylene glycol.Its average molecular weight was 267g/mol and the product yield was 82.40%.