Recycling of High-Value-Added Aramid Nanofibers from Waste Aramid Resources via a Feasible and Cost-Effective Approach

Bin Yang; Weiwei Li; Meiyun Zhang; Lin Wang; Xueyao Ding

doi:10.1021/acsnano.1c00463

Recycling of High-Value-Added Aramid Nanofibers from Waste Aramid Resources via a Feasible and Cost-Effective Approach

ACS Nano. 2021 Apr 27;15(4):7195-7207. doi: 10.1021/acsnano.1c00463. Epub 2021 Mar 22.

Authors

Bin Yang^{1

2}, Weiwei Li¹, Meiyun Zhang¹, Lin Wang¹, Xueyao Ding¹

Affiliations

¹ College of Bioresources Chemical and Materials Engineering, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi Province Key Laboratory of papermaking Technology and Specialty paper Development, Shaanxi University of Science & Technology, No. 6, Xuefu Road, Xi'an 710021, China.
² State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510641, China.

PMID: 33752335
DOI: 10.1021/acsnano.1c00463

Abstract

High-performance aramid fibers are extensively applied in the civil and military fields. A great deal of waste aramid resources originating from the manufacturing process, spare parts, or end of life cycle are wrongly disposed (i.e., landfill, smash, fibrillation), causing a waste of valuable resources as well as severe environmental pollution. Although aramid nanofibers (ANFs) have recently been recently reported as one of the most promising building blocks due to their excellent properties, they suffer from an extremely high production expenditure, thereby greatly hindering their scale-up application. Herein, in this paper, from a resources-saving and cost-reductional perspective, we present a feasible top-down approach to recycle high value-added ANFs with an affordable cost from various waste aramid resources. The results indicate that although the reclaimed ANFs have a molecular weight reduction of 8.1% compared with the recycled aramid fibers, they still exhibit a molecular weight of 43.0 kg·mol^-1 that represents the highest value compared to other methods. It is noteworthy that the fabrication cost of ANFs is significantly reduced (∼7 times) due to the reclamation of waste aramid fibers instead of the expensive virgin aramid fibers. The obtained ANFs show impressive tensile strength (149.2 MPa) and toughness (10.43 MJ·m^-3), excellent thermal stabilities (T_d of 542 °C), and a high specific surface area (65.2 m²·g^-1), which endows them to be promising candidates for constructing advanced materials. Compared to the aramid pulp obtained by the traditional recycling method, ANFs show significant advantages in dimensional homogeneity, aspect ratio, dispersibility, film-forming property, and especially the excellent properties of the ANF film. In addition, the scale-up preparation of ANFs from the recycled waste aramid fibers is carried out, demonstrating it is highly economically viable. Therefore, this work provides a highly feasible and cost-effective recycle system to reclaim the waste aramid resources together with significantly reducing the preparation cost of ANFs.

Keywords: aramid nanofibers; molecular weight; preparation cost; reclamation; waste aramid fiber.