1. Gansu Key Laboratory of Environmental Friendly Composites and Biomass Utilization College of Chemical Engineering, Northwest University for Nationalities Lanzhou Gansu 730030 People's Republic of China
2. Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory of Eco‐environment‐Related Polymer Materials Ministry of Education, Northwest Normal University Lanzhou Gansu 730070 People's Republic of China