Abstract
The biodegradabilities of poly(butylene succinate) (PBS) powders in a controlled compost at 58 °C have been studied using a Microbial Oxidative Degradation Analyzer (MODA) based on the ISO 14855-2 method, entitled “Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions—Method by analysis of evolved carbon dioxide—Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test”. The evolved CO2 was trapped by an additional aqueous Ba(OH)2 solution. The trapped BaCO3 was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS) to determine the percent modern carbon [pMC (sample)] based on the 14C radiocarbon concentration. By using the theory that pMC (sample) was the sum of the pMC (compost) (109.87%) and pMC (PBS) (0%) as the respective ratio in the determined period, the CO2 (respiration) was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO2 amount from PBS in the sample vessel were about 30% lower than those based on the ISO method. These differences between the ISO and AMS methods are caused by the fact that part of the carbons from PBS are changed into metabolites by the microorganisms in the compost, and not changed into CO2.
Highlights
Biodegradable plastics are expected to be used for food containers which can be treated with food waste for composting and methane fermentation [1]
Biodegradation of poly(butylene succinate) (PBS) Evaluated from the Blank and Sample Vessels Based on ISO 14855-2
The method used for the determination of the biodegradability of the PBS powders was based on the International Standard (ISO 14855-2) that measures the evolved CO2 amount from both the blank vessel without a sample and the sample vessel including a 10 g PBS powder sample, 144 g mature compost, and 320 g sea sand
Summary
Biodegradable plastics are expected to be used for food containers which can be treated with food waste for composting and methane fermentation [1]. The evolved CO2 amount itself from a sample vessel cannot be used to calculate directly the degree of biodegradation, because this evolved CO2 value includes the respirated CO2 from the active and alive inoculums, such as the compost in the test environment as shown in Figure 3 (a). It was found that the AMS method for the evaluation of biodegradation can separately determine the evolved CO2 from respiration and biodegradation of PCL by calculating the pMC in the evolved CO2 from one sample vessel. The degree of biodegradation of PBS powders (Av. 157.8 m) has been studied in a controlled compost at 58 °C using the Microbial Oxidative Degradation Analyzer (MODA) with sample and blank vessels based on ISO 14855-2. The degree of biodegradation for PBS powders have been evaluated in a compost at 58 °C using MODA by measuring the 14C concentration in the evolved CO2 only from the sample vessel. The 14C concentrations in the evolved CO2 were measured by AMS to evaluate the respiration and biodegradation of CO2 evolved from the sample vessel
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
