Evaluation of compostability of commercially available biodegradable packages in real composting conditions

摘要: The adoption of biodegradable packaging materials is increasing in food and consumer good applications. Currently, poly(lactide) (PLA) polymers are the biggest commercially available bio-based material. Life cycle analyses show that production PLA consumes around two times less energy than conventionally petroleum based polymers. Therefore, first issue needs to be addressed its environmental impact. disposal such polymeric residues composting facilities can an important method reducing amount disposed as municipal solid waste. To best our knowledge, there has been no study done evaluating compostability a complete package real-time conditions. real conditions differ from simulated ones due several factors weather, microbial growth pH; therefore packages affected. This addresses packages, bottle tray, degradation composed 96% L-lactide 4% D-lactide with bluetone additive tray 94% 6% were evaluated pile having temperatures 65oC ± 5oC (150°F 10°F), relative humidity 65% 5% wet weight moisture content pH 8.5 0.5. placed compost duplicate sets taken out on 1, 2, 4, 6, 9, 15, 30 days. molecular (MW) glass transition (Tg), melting (Tm) decomposition (TD) monitored assess changes packages' physical properties. MW was assessed by gel permeation chromatography (GPC), Tg Tm differential scanning calorimetry (DSC), TD thermogravimetric analysis (TGA). In addition, visually inspected for color, texture, shape thickness pictures configurations evolved. After 4 days being pile, initial fragmentation observed. At 15 days, trays started become part whereas bottles showed slower breaking apart. at 6 bottles, reduction 77% 85% observed, respectively. reduced 209,324 Daltons 10,686 176,315 4,708 after 4,000 Daltons, completely degraded. Similarly decline both 30% 18%, 2.4% 3.9%, 396.1°C 396.8°C, respectively; they 358.1°C 326.2°C. difference between time attributed their crystallinity. degrade under realtime much faster previous studies reporting