Thermogravimetric and Kinetics of Thermal Degradation of Powdered Laboratory Examination Gloves: 1. Analysis of Thermal Scan Traces from 310-455ºC
Nasrollah Hamidi *
Department of Biological and Physical Sciences, South Carolina State University, Orangeburg, SC 29117, USA.
Ruhullah Massoudi
Department of Biological and Physical Sciences, South Carolina State University, Orangeburg, SC 29117, USA
Sujan Shrestha
Department of Mathematics and Computer Sciences, South Carolina State University, Orangeburg, SC 29117, USA.
Marketa Marcanikova
Department of Biological and Physical Sciences, South Carolina State University, Orangeburg, SC 29117, USA.
Sihan Chang
Department of Civil and Mechanical Engineering, South Carolina State University, Orangeburg, SC 29117, USA
Louis Whitesides
1890–Research, South Carolina State University, Orangeburg, SC 29117, USA.
*Author to whom correspondence should be addressed.
Abstract
The aim of this study was to develop an energy efficient method to decompose powdered laboratory safety examination gloves (PLEG). This paper reports on the results of thermogravimetric analysis (TGA) of PLEG without a catalyst. The study was conducted in the Department of Biological and Physical Sciences at South Carolina State University (SCSU), Orangeburg, SC, USA, during the spring of 2014. Twelve samples of PLEG were studied under three types of operating conditions. First a sample was scanned from 50°C to 800°C with a heating rate of 10°C/min while it was purged with 10 mL/min argon. The results of this study determined the thermal stability of PLEG and the temperature of highest weight loss rate (~410°C). The second approach used two sequential dynamic thermal scans with a linear and fast (200°C/min) increase of the temperature over time, and two sequential isothermal steps for 30 minutes; one below 410°C and the other at 410°C. The third approach used a dynamic thermal scan and a sequential isothermal step for 30 minutes at a temperature over 410°C. From the thermal scans and isotherms, the highest rate of weight loss, the temperature at the maximum weight loss, the acceleration of weight loss by thermal scan, the deceleration of weight loss at the isotherms, the rate constant and the activation energy of weight loss (Ea) were estimated. The experimental results confirmed that Ea of weight loss of the PLEG samples depended on the temperature of operation. At temperatures below 430°, the amount of Ea for the weight loss of sample were higher than those above 430°C temperatures. Also, internal reactions of the sample of PLEG at 340°C resulted on thermally stable materials, which slowed down the thermolysis rate of the sample at higher temperatures.
Keywords: Thermogravimetric, latex-gloves, kinetics, environment, pollution, pyrolysis, thermolysis, neoprene, activation-energy, rate-constant