Abstract: The blends of PLLA/WS were prepared using poly(L-lactic acid)(PLLA) and wheat straw(WS) in N-methyl morpholine-N-oxide(NMMO)solution.WS was firstly dissolved in NMMO,then PLLA was successively dissolved in the WS solutions to get homogeneous mixture solutions.The mixtures were cast to prepare PLLA/WS blends.Differential scanning calorimetry,X-ray diffraction,Fourier transform infrared spectroscopy,thermogravimetry,and scanning electron microscopy were employed for the characterization of the blends.The results showed that PLLA and WS could form a homogeneous mixture in NMMO.A strong interaction between PLLA and WS was observed.The crystal structures were formed as the PLLA content was under 50%.With the increase of PLLA contents,the thermostability and melting points of PLAA/WS were gradually increased.The blend films possessed smooth section and micropore due to the compatibility between PLLA and WS.The biodegradable polymeric materials with different properties could be prepared through modifying the ratios of PLLA to WS.

Key words: poly(L-lactic acid), wheat straw, blend, compatibility