聚氯乙烯(PVC)类医疗废物的热解特性研究

为研究含聚氯乙烯医疗废物的热解特性,选取输液管和尿样盒为对象,利用差热热重分析仪,在氮气气氛下进行热重实验,探讨了二者热失重行为和机制,分析了反应过程中热量变化及热解剩余物性状,建立了反应动力学模型.结果表明,输液管和尿样盒的降解过程以主要成分PVC的热解机制为主导,分别在约200～390℃和约390～550℃区间内,呈现两段主要的热解过程,最大热解速率分别出现在315℃和470℃左右;增塑剂可降低样品脱氯的温度并增加失重率,样品复杂的成分导致失重峰不规则且不平滑;热解过程为吸热反应,呈现2个明显的阶段,分别对应试样的两段热解,热延迟的存在导致DTA峰温稍滞后于对应的DTG峰温;建立的"整体两步四反应模型"能很好地描述输液管和尿样盒的热解行为.

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.