Author(s)

Do Khoa Thi Lanh^1*, Tran Duc Thien²

¹Department of Polymer Science and Materials, Sichuan University, Chengdu, China.
²Vietnam National University of Forestry, Hanoi, Vietnam.

This paper aims to investigate the water absorption of wood flour/polypropylene composites and its effects on dimensional stability and crystallization properties. Wood-plastic composites (WPCs) makes using polydopamine modified wood flour (WF-D), virgin polypropylene, maleic anhydride-grafted polypropylene (MA) and antioxidant, by using hot-pressing moulding. Water absorption (WA), thickness swelling (TS) and failure of flexural properties of the composites have studied for a range of immersion times. It is found that the WA and TS have increased with WF content and immersion time. The water absorption and thickness swelling of WPCs are 0.85% and 0.99%, respectively, after 8 days immersion. With the prolonging of immersion time, the impact strength, flexural strength and flexural modulus of WPCs increase first and then decrease. The impact strength decreases from 3.32 kJ/m² to 2.94 kJ/m², the retention rate is 88.55%; the flexural strength and flexural modulus by 68.58 Mpa and 3.92 Gpa, respectively. WPCs crystallization and thermal properties decrease slightly. Microstructures of the composites are examined to understand the mechanisms for the wood-plastic interaction which affects the water absorption and thickness swelling. Our work demonstrates that using polydopamine treatment wood flour for preparing WPCs can be an efficient way to improve the water resistance of WPCs.

Wood Flour, Water Absorption, Polypropylene, Wood-Plastic Composites, Polydopamine, Thickness Swelling

Lanh, D. and Thien, T. (2016) Study on Water Resistance of Polydopamine Treatment Wood Flour/Polypropylene Composites. Journal of Materials Science and Chemical Engineering, 4, 7-15. doi: 10.4236/msce.2016.45002.