[Pyrolysis characteristics of medical waste compositions containing PVC (polyvinyl chloride)].

To obtain pyrolysis characteristics of medical waste compositions containing PVC (polyvinyl chloride), thermogravimetric study of tube for transfusion (TFT) and sample collector for urine (SCFU) was carried out using the thermogravimetric analyser (TGA) with N2. The heat change in pyrolysis process was analyzed and the properties of pyrolysis residues are reported. The mathematics model with two-step and four-reaction was established to simulate the pyrolysis process. The results show that: 1) The pyrolysis mechanism of the two samples is in agreement with that of PVC. The decomposition process appears two stages in 200 - 390 degrees C and 390 - 550 degrees C, which are clearly expressed with two prominent peaks with maximum rate of weight loss at about 315 degrees C and 470 degrees C. 2) Complex ingredients in samples result in irregular and uneven shape of DTG peaks, in which plasticizer lowers the antichloration temperature and enhances the weight loss rate. 3) The model could satisfactorily describe the weight loss and differential process of TFT and SCFU.