Reprocessability of PLA through Chain Extension for Fused Filament Fabrication
Reprocessability of PLA through Chain Extension for Fused Filament Fabrication
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DOI：
10.3390/jmmp6010026
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发表时间：
2022-02-01
影响因子：
3.2
通讯作者：
Neto, Victor
中科院分区：
文献类型：
--
作者：
Correia, Carlos;Gomes, Tiago E. P.;Neto, Victor
随着增材制造（AM）技术在塑料加工领域越来越受欢迎，建立闭环回收策略以最大限度地提高加工材料的价值，从而提高其可持续性已成为一个主要问题。然而，与回收材料的性能相关的挑战有待克服，因为在机械回收后，热塑性塑料的分子降解会改变其性能和加工性能。在这项工作中，假设在再加工过程中加入扩链剂（CE）将使我们能够克服这些缺点。为了证明这一猜想，1，3-双（4，5-二氢-2-恶唑基）苯（PBO），用作CE，对聚乳酸（PLA）的力学，热，流变性能的影响进行了研究。此外，尝试了基于熔融长丝制造（FFF）的闭环回收系统，包括材料制备，长丝挤出，3D组件的生产和机械回收步骤。PBO部分恢复了回收的PLA的机械性能，这反映在与不含PBO的回收的PLA相比，拉伸模量（+13%）和拉伸强度（+121%）均增加。进行了印刷适性测试，材料的脆性行为是成功建立FFF应用闭环回收方案的主要限制。
As additive manufacturing (AM) technologies have been gaining popularity in the plastic processing sector, it has become a major concern to establish closed-loop recycling strategies to maximize the value of the materials processed, therefore enhancing their sustainability. However, there are challenges to overcome related to the performance of recycled materials since, after mechanical recycling, the molecular degradation of thermoplastics shifts their performance and processability. In this work, it was hypothesized that the incorporation of a chain extender (CE) during the reprocessing would allow us to overcome these drawbacks. To attest this conjecture, the influence of 1,3-Bis(4,5-dihydro-2-oxazolyl)benzene (PBO), used as a CE, on mechanical, thermal, and rheological properties of polilactic acid (PLA) was studied. Furthermore, a closed-loop recycling system based on Fused Filament Fabrication (FFF) was attempted, consisting of the material preparation, filament extrusion, production of 3D components, and mechanical recycling steps. PBO partially recovered the recycled PLA mechanical performance, reflected by an increase in both tensile modulus (+13%) and tensile strength (+121%), when compared with recycled PLA without PBO. Printability tests were conducted, with the material's brittle behavior being the major constraint for successfully establishing a closed-loop recycling scheme for FFF applications.