Bio-Based Hydrogel and Aerogel Composites Prepared by Combining Cellulose Solutions and Waterborne Polyurethane

Ling-Jie Huang,Yi-Chun Chen,Wen-Jau Lee

doi:10.3390/polym14010204

Abstract

Hydrogel composites can be prepared from cellulose-based materials and other gel materials, thus combining the advantages of both kinds of material. The aerogel, porous material formed after removing the water in the hydrogel, can maintain the network structure. Hydrogel and aerogel have high application potential. However, low mechanical strength and weight loss of cellulose hydrogel due to the water dehydration/absorption limit the feasibility of repeated use. In this study, cellulose hydrogels were prepared using microcrystalline cellulose (MC), carboxymethyl cellulose (CMC), and hydroxyethyl cellulose (HEC) as raw materials. Waterborne polyurethane (WPU) was added during the preparation process to form cellulose/WPU composite hydrogel and aerogel. The influence of the cellulose type and WPU addition ratio on the performance of hydrogel and aerogel were investigated. The results show that the introduction of WPU can help strengthen and stabilize the structure of cellulose hydrogel, reduce weight loss caused by water absorption and dehydration, and improve its reusability. The mixing of cellulose and WPU at a weight ratio of 90/10 is the best ratio to make the cellulose/WPU composite aerogel with the highest water swelling capacity and heat resistance.

Highlights

Hydrogel is a polymeric network material with low crosslink density, which has swelling ability and retains a large amount of water in the structure but is not soluble in water or solvents [1,2,3]
This study successfully introduced Waterborne polyurethane (WPU) resin into cellulose hydrogel to prepare cellulose/WPU composite hydrogel and aerogel
The compression test shows that the structure of cellulose-based materials is the most important factor affecting the compressive stress of the composite hydrogel

Summary

Introduction

Hydrogel is a polymeric network material with low crosslink density, which has swelling ability and retains a large amount of water in the structure but is not soluble in water or solvents [1,2,3]. Hydrogels can be formed into lightweight, highly porous aerogels by appropriate dehydration methods while maintaining their network structure. This aerogel can absorb liquid several times its weight [4,5,6]. The hydrogels and aerogels prepared from cellulose could combine their advantages. There have been many studies related to the application of cellulose hydrogels and aerogels, including controlled drug release [8,9,10], water and oil absorbents [11,12,13,14], and heavy metal adsorption [15,16,17]

Methods

Results

Conclusion