New plastic blends for complete degradation Imagine a wonderful vision of throwing empty plastic water bottles into household compost bins, breaking down plastics and producing biogas and powering the home. Now, researchers show that bioplastics and certain mixtures can decompose under different conditions, indicating that we have taken an important step toward this future. And they reported their results in the ACS journal Environmental Science & Technology.
White pollution is a global environmental problem, especially in the oceans – plastic fragments or plastic strips can damage or entangle animals and birds in the ocean, so that these animals die. Although plastic recycling levels have increased in many countries, most plastic waste is still present in landfills or in our living environment. Scientists have developed biodegradable plastics, but they often lack the flexibility, strength or toughness of traditional plastics. Mixtures of different bioplastics can improve these properties, but their consistency with the environment is uncertain. Tanja Narancic, Kevin O’Connor, Ramesh Babu Padamati and colleagues wanted to study the degradation of various bioplastics and their mixtures under various conditions.
The researchers studied the degradation of 15 different plastics and their mixtures under artificially managed conditions, ie degradation under composting and anaerobic conditions. And degradation in unmanaged environments, ie in soil and fresh water or seawater. Polylactic acid (PLA) is one of the best-selling biodegradable plastics on the market, but it needs to be decomposed under high temperature conditions and cannot be composted at home. Surprisingly, under typical home composting conditions, a mixture of PLA and polycaprolactone (PCL) is fully degradable to carbon dioxide, biomass and water. Many individual plastics and mixtures have been tested to decompose under anaerobic digestion conditions, which produce biogas and all of which are degraded by industrial compost. Researchers say biodegradable plastic mixtures can create new possibilities for the management of plastic waste. However, under all soil and water conditions, only two plastics, polyhydroxybutyrate (PHB) and thermoplastic starch (TPS), are completely decomposed. Therefore, biodegradable plastics are not the best way to solve plastic pollution. Researchers point out that biodegradable plastics must be effectively managed by consumers.
