Search Results
Abstract
Organic peroxides are commonly employed as an initiator for polymerization, a source of free radicals, a hardener, and a linking agent. Due to its relatively weak oxygen-oxygen bond, di-tert butyl peroxide (DTBP) has been categorized as flammable type or Class III by the National Fire Protection Association (NFPA). The transport of dangerous goods (TDG) has published a warning against DTBP that it could potentially induce violent heat, explosion, fire and self-ignition under certain circumstances. DTBP has been recommended as an international standard sample for estimating the performance of several calorimeters, such as glass tube tests, differential scanning calorimetry (DSC), and vent sizing package 2 (VSP2). In this study, we measured the precise temperature changes and heat flow with the above-mentioned testing instruments. However, some runaway incidents caused by DTBP have demonstrated the reaction temperature could be as low as ambient temperature. The reactivity and the hazardous incompatibility with sulfuric acid (H2SO4) and hydrochloric acid (HCl) of DTBP have not been evident, and the runaway hazards involved in different processing conditions were clarified in this study by implementing the two calorimeters. Acid-catalyzed characteristics and reaction hazards of DTBP could be acquired, such as heat of decomposition (ΔH d) and exothermic onset temperature (T 0).
catalytic reaction [ 1 ]. In addition, CHP is as an initiator for polymerization that is used to yield the acrylonitrile–butadiene–styrene (ABS) resin [ 2 ]. In general, di-tert-butyl peroxide (DTBP) is a strong source of radicals in that the
Abstract
Reaction hazards remain the most serious concern in the chemical industry in spite of continual research and attention devoted to them. Many commercial calorimeters, such as the Differential Scanning Calorimetry (DSC), are useful screening tools for thermal risk assessment of reaction hazards. Some important thermodynamic and kinetic parameters, including onset temperature, adiabatic time to maximum rate, and maximum adiabatic temperature, were analyzed in this paper. A kinetic-based model under adiabatic conditions was developed, and the adiabatic time to maximum rate was estimated. Correlations between onset temperature (T o) and activation energy (E a), and between onset temperature (T o) and adiabatic time to maximum rate (TMR ad) were found, and were illustrated by some examples from the previous literature. Based on the heat of reaction and the adiabatic time to maximum rate, a thermal risk index (TRI) was defined to represent the thermal risk of a specific reaction hazard relative to di-tert-butyl peroxide (DTBP), and the results of this index were consistent with those of the reaction hazard index (RHI). The correlations and the thermal risk index method could be used as a preliminary thermal risk assessment for reaction hazards.
,500 * * 1 Di-tert-butyl peroxide (DTBP) 115 1,200 80 80 1
peroxide (MEKPO), di-tert-butyl peroxide (DTBP), tert-butyl peroxybenzoate (TBPB), cumene hydroperoxide (CHP), tert-butyl hydroperoxide (TBHP), lauroyl peroxide (LPO), benzoyl peroxide (BPO), and dicumyl peroxide (DCPO), etc. The important reason for
polymerization, such as methyl ethyl ketone peroxide (MEKPO), di- tert -butyl peroxide (DTBP), cumene hydroperoxide (CHP), and tert -butyl peroxy-2-ethyl hexanoate (TBPO) [ 7 ]. We focused on major analysis of the thermal hazard characteristics for TBPO, which
down due to their highly active characteristics. OPs also react with external materials, such as may be kept nearby in storage facilities, in various ways resulting in large discharges of energy [ 1 – 5 ]. Di- tert -butyl peroxide (DTBP) is one commonly