Journal of Cleaner Production ( IF 11.1 ) Pub Date : 2020-07-28 , DOI: 10.1016/j.jclepro.2020.123353 Martin Liu , Mohammad Arshadi , Farhad Javi , Peter Lawrence , Seyed Mohammad Davachi , Alireza Abbaspourrad
In this work, we report a green, waste-free method of synthesizing hydrophobic bioplastic films from tea waste, an industrial byproduct of tea brewing. Utilizing only spent tea leaves, citric acid, and water—all of which can be sustainably sourced—this facile technique is completely non-toxic, generates zero waste, and requires mild conditions and short processing times. The resultant bioplastics were chemically characterized by XPS and HPLC-MS, mechanically characterized by uniaxial tensile tests, and surface characterized by contact angle, SEM, and confocal microscopy. Citric acid did not fully react with the tea waste matrix (53.6% reaction efficiency), yet it is hypothesized that unreacted citric acid acts as a hygroscopic plasticizer in the bioplastic films, which exhibited an ultimate tensile strength of 6.16 MPa and an elongation at break of 13.33%. The tea waste bioplastics demonstrated strong hydrophobic character with a water contact angle of up to 117°, which we attempted to explain by quantifying the surface roughness of the films. Mechanical and hydrophobic characteristics were also found to be dependent on relative humidity. Biodegradable and sustainably sourced, these tea waste bioplastics and the findings herein represent a step towards more sustainable packaging solutions.
中文翻译:
用茶渣绿色便捷地制备疏水性生物塑料
在这项工作中,我们报告了一种绿色的,无浪费的方法,可从茶渣(一种茶酿造的工业副产品)中合成疏水性生物塑料薄膜。仅使用废茶叶,柠檬酸和水-所有这些都可以可持续地获取-这种简便的技术是完全无毒的,产生零废物,并且需要温和的条件和较短的处理时间。所得生物塑料通过XPS和HPLC-MS进行化学表征,通过单轴拉伸测试进行机械表征,通过接触角,SEM和共聚焦显微镜对表面进行表征。柠檬酸未与茶渣基质完全反应(反应效率为53.6%),但据推测未反应的柠檬酸在生物塑料薄膜中起吸湿增塑剂的作用,其极限拉伸强度为6。16 MPa,断裂伸长率13.33%。茶废生物塑料表现出很强的疏水性,与水的接触角高达117°,我们试图通过量化薄膜的表面粗糙度来解释。还发现机械和疏水特性取决于相对湿度。这些茶废生物塑料是可生物降解的和可持续的来源,其发现也代表了朝着更可持续的包装解决方案迈进的一步。