Evaluation of toxicity and biodegradation of thermoplastic starch foams with modified starch

Packaging made with thermoplastic starch (TPS) foams is a great alternative to replace non-biodegradable single-use packaging. TPS foams are of great interest, as they are biodegradable and from renewable sources. Although these foams are hydrophilic, chemical modifications to the starch used to make the foams can make them more resistant to the action of water and moisture. These modifications make the starch more hydrophobic, but they can affect the biotoxicity and biodegradation properties of these starches, important characteristics for environmentally friendly materials. In this work, the toxicity and biodegradability of TPS foams with modified starches were studied. Four types of starch were tested: acetylated starch, esterified starch, 3-chloropropyl trimethoxysilane starch and methyltrimethoxysilane starch. To evaluate the samples, the Allium cepa test, composting, biodegradation via respirometry and enzymatic degradation were used. The results showed that acetylated starch and esterified starch showed toxicity and that all foams showed some degree of biodegradability.