Study on Exothermic Oxidation of Acrylonitrile-butadiene-styrene (ABS) Resin Powder with Application to ABS Processing Safety

Abstract

Oxidative degradation of commercial grade ABS (Acrylonitrile-butadienestyrene) resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB) contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC). Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile)) matrix. Heat of oxidation was first determined to be 2,800  40 J per gram of ABS or 4,720  20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation OPEN ACCESSPolymers 2010, 2 175 verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.

Blends of rABS and SEBS: Influence of In-Situ Compatibilization on the Mechanical Properties

“…Acrylonitrile–butadiene–styrene (ABS), which is a typical engineering polymer, has a huge market share in raw materials, in view of its excellent properties, such as outstanding notch impact resistance, high modulus caused by the benzene ring, and the oil resistance that is brought by the nitrile group [4,5,6]. Nevertheless, the repeated use of waste ABS has faced with a series of conundrums, including the loss of toughness, the decline in molecular weight, and the deterioration of surface quality, which has resulted in serious obstacles in the extensive application of recycled acrylonitrile–butadiene–styrene copolymer (rABS) [7,8].…”

A Statistical Analysis on the Effect of Antioxidants on the Thermal-Oxidative Stability of Commercial Mass- and Emulsion-Polymerized ABS

“…Földes and Lohmeijer [20] studied the performance of two commercial primary AOs (Irganox 1076 and Irganox 245) on the oxidative degradation of polybutadiene and concluded that, up to 2 m% of AO, Irganox 1076 presented better AO efficiency in oven aging (at 100 °C), whereas Irganox 245 showed higher efficiency in differential scanning calorimetry (DSC) experiments at 190 °C. Duh et al [21] studied the oxidation of ABS (PB contents from 25 to 60 m%), using higher amounts of AO for ABS with higher PB content, and verified that the oxidation onset temperature was influenced by the AO, not by the quantity of PB. Motyakin and Schlick [22] investigated the effect of a hindered amine stabilizer (HAS, commercially known as Tinuvin 770; 1 or 2 m%) on the thermal degradation of two ABS materials (one prepared by mass polymerization containing 10 m% butadiene, and the other by emulsion polymerization containing 25 m% butadiene) and observed, at first sight, an unexpected faster degradation of polymer samples that contained a higher HAS content (2 m%).…”

HTPB-Polyurethane: A Versatile Fuel Binder for Composite Solid Propellant

“…The content of these units varies from polymer to polymer. Generally, these olefinic groups are of different reactivity in the oxidation reaction (Duh et al, 2010). As a result, the per centage of cis-1,4-; trans-1,4-; and vinyl-1,2-olefinic groups in the HTPB may have great effect on oxidation rates and product composition.…”