文献类型：期刊文献

英文题名：Superelastic and flexible 3D printed waterborne polyurethane/cellulose nanofibrils structures

作者：Chen, Yuan[1,2] Yu, Zhengyang[2] Oguzlu, Hale[2] Jiang, Jungang[2] Cho, MiJung[3] Karaaslan, Muzaffer[3] Renneckar, Scott[3,4] Jiang, Feng[2,4]

第一作者：Chen, Yuan;陈媛

通信作者：Jiang, F[1]

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, 1 Dongxiaofu Xiangshan Rd, Beijing 100091, Peoples R China;[2]Univ British Columbia, Dept Wood Sci, Sustainable Funct Biomat Lab, Vancouver, BC V6T 1Z4, Canada;[3]Univ British Columbia, Dept Wood Sci, Adv Renewable Mat Lab, Vancouver, BC V6T 1Z4, Canada;[4]Univ British Columbia, BioProd Inst, Vancouver, BC V6T 1Z4, Canada

年份：2021

卷号：46

外文期刊名：ADDITIVE MANUFACTURING

收录：;EI(收录号：20212510538902);Scopus(收录号：2-s2.0-85108240205);WOS:【SCI-EXPANDED(收录号:WOS:000697355900001)】；

基金：This research was undertaken, in part, thanks to funding from the Canada Research Chairs program (231928) . We gratefully acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) [RGPIN-2018-06818] . Dr. Yuan Chen would acknowledge the support of National Nonprofit Institute Research Grant of Chinese Academy of Forestry (CAFYBB2019GC001-10) and the Na-tional Natural Science Foundation of China (31700480) .

语种：英文

外文关键词：3D printing; Waterborne polyurethane; Cellulose nanofibrils; Hygroscopic; Shape recovery

摘要：Waterborne polyurethane (WPU) is a type of environmental-friendly aqueous suspension that has been widely used in varied applications. However, it remains a challenge to use WPU for three-dimensional structures by additive manufacturing due to its unsatisfied rheological properties. In this study, we developed an in-situ synthesis method to modify WPU (WPUCNF) by using cellulose nanofibrils (CNF) in order to enhance its printability. The addition of CNF during emulsification reduced the WPU nanoparticles size as well as increased the suspension viscosity. To further improve the printability, additional CNFs were added as rheological modifiers. After dewatering the suspension, WPUCNF/CNF composite inks showed excellent printability, as illustrated by the printed structures of various shapes such as honeycomb, woodpile, or human ear. For these samples, heights over 10 mm could be printed with good shape fidelity at the ink concentration of as low as 2.8-7.4%, significantly lower than previously reported WPU ink for 3D printing (similar to 20-30%). The 3D printed structure can absorb 17-37% of water due to the presence of hygroscopic salt CaCl2, and demonstrated high flexibility and withstood over 20 compressive cycles. This versatile WPUCNF/CNF ink can be adapted for designing hierarchical porous 3D structures with broad emerging applications in the biomaterials field.