Mechanical properties and hygroscopicity of polylactic acid/wood-flour composite

The wood-flour was modified by polylactic acid(PLA) and maleic anhydride(coupling agent,MAPP).Composite materials were prepared by melt blending.The mechanical properties and water absorption of the wood-flour/PLA composite were researched,and the relationship between the macroscopic properties and the micro-characteristics was also analyzed.The results showed that with the wood-flour contents varied from 10g to 25g,the maximum tension increased 4 times,and the tensile strength increased 3 times.With the addition of MAPP,the increments of maximum tension and tensile strength were doubled.With the increase of wood components,the water absorbing capacity increased simultaneously,the maximum increment after 2h was 2.85%,and after 24h was 8.12%.The use of MAPP decreased the water absorbing capacity,the maximum increment after 2h was 0.72%,and after 24h was 3.58%.With scanning electron microscope(SEM),we can find that when the MAPP was added into the wood-flour,the interface became more smooth,and the adhesion between the PLA and wood-flour became more closely.