OW18-Study on Fiber Intercalation and Fiber-reinforcing Effects of Nanocellulose Waterborne Polyurethane Composites

陳欣辰¹、黃英治²、吳建欣²、鄭如忠²、張豐丞^{1 *}

¹ 國立臺灣大學森林環境暨資源學系。臺北市大安區羅斯福路四段一號。

² 國立臺灣大學高分子科學與工程學研究所。臺北市大安區羅斯福路四段一號。

^* 通訊作者：fcchang@ntu.edu.tw

Waterborne polyurethanes (WPUs) have drawn attention nowadays since their features of non-volatile, non-toxic, and environmentally friendly when compared with the widely used solventborne polyurethanes. Nevertheless, WPUs’ mechanical and thermal properties pale in comparison to those of solventborne polyurethanes. Therefore, in order to enhance the properties and broaden the applicability of WPUs, also by considering the compatibility of the materials, cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs) were added into the cationic WPUs forming robust green composites. The nanocellulose with hydrophilic nature mixed well with the WPU matrices during the blending process by sonication. Zeta potential analysis and particle size analysis revealed the interactions between the nanocellulose and the WPUs, including the surface charge differences of the neat WPUs and the resulting composites, and the bonding interactions between the components, respectively. According to the tensile tests and thermogravimetric analysis results, the addition of nanocellulose addition to WPUs would greatly increase the mechanical properties and slightly improve the thermal stability. Water sorption tests and UV-vis spectroscopy results also presented supporting messages on the hygroscopicity and transparency of the composite films in this study. By investigating the fiber reinforcing effects in these nanocellulose-WPU composites, some reference information and the feasibility of further applications were provided.