Gazdus Hannah B, Shen Sabrina C, Lee Nicolas A, Buehler Markus J
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
School of Architecture and Planning, Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
3D Print Addit Manuf. 2025 Apr 14;12(2):122-130. doi: 10.1089/3dp.2024.0014. eCollection 2025 Apr.
The growing environmental impacts of solid waste accumulation have resulted in an increased demand for biodegradable alternatives to conventional plastics. While several products have begun to gain popularity as biodegradable or compostable plastics, these often still negatively impact terrestrial and aquatic environments, as they frequently require precise conditions in order to fully decompose. Furthermore, standards for measuring biodegradation rates are often complex and poorly representative of real disposal sites, limiting their widespread use and applicability. In this study, we present four simple tests to assess the environmental degradability of materials without specialized equipment and demonstrate them with a series of 3D printable biotic composites composed of pectin, chitosan, and cellulose, abundant and organic biopolymers known to be degradable by common microorganisms. Five different compositions were degraded in live soil, worm burial, high humidity, and aqueous environments, and demonstrated rapid degradation with up to 100% mass loss after 21 days for a pectin-based material buried in worm-laden oil. Degradability was further found to be tunable, with decreasing degradation rate as chitosan content increased. Our results confirm that biotic composites degrade more rapidly than conventional plastics and provide accessible methods that can enable more widespread material testing for the development of sustainable material alternatives, especially to gather basic environmental degradation information representative of typical solid waste discard conditions. We anticipate that these degradation methods and the materials degraded therein will provide further impetus for reducing waste from 3D printing and for considering end of life when designing products.
固体废物堆积对环境的影响日益增大，这导致对传统塑料的可生物降解替代品的需求增加。虽然有几种产品已开始作为可生物降解或可堆肥塑料受到欢迎，但这些产品往往仍会对陆地和水生环境产生负面影响，因为它们通常需要精确的条件才能完全分解。此外，衡量生物降解率的标准往往很复杂，而且不能很好地代表实际处置场所的情况，这限制了它们的广泛使用和适用性。在本研究中，我们提出了四种简单的测试方法，无需专门设备即可评估材料的环境可降解性，并用一系列由果胶、壳聚糖和纤维素组成的3D可打印生物复合材料进行了演示，果胶、壳聚糖和纤维素是已知可被常见微生物降解的丰富有机生物聚合物。五种不同的组合物在活土、蠕虫掩埋、高湿度和水环境中进行了降解，对于埋在充满蠕虫的土壤中的一种基于果胶的材料，在21天后显示出快速降解，质量损失高达100%。进一步发现，可降解性是可调的，随着壳聚糖含量的增加，降解速率降低。我们的结果证实，生物复合材料的降解速度比传统塑料更快，并提供了可广泛使用的方法，能够为可持续材料替代品的开发进行更广泛的材料测试，特别是为收集代表典型固体废物丢弃条件的基本环境降解信息。我们预计，这些降解方法及其中降解的材料将为减少3D打印产生的废物以及在设计产品时考虑产品寿命终结提供进一步的推动力。
