Effects of alkalli treatment(AT)

modification by benzoic acid(BA) or/and stearic acid(SA) on mechanical properties

thermal stability

rheological properties

wettability and water uptake of wheat straw powder(WSP) reinforced polypropylene(PP) composites(WSP/PP-CM) were studied. Results show that

when WSP was alkalli treated

the tensile trength(TS)

flexural strength(FS)

impact strength(IS)

initial decomposition temperature(T

i

) of WSP/PP-CM and the contact angle(

θ

) between WSP/PP-CM and distilled water can be increased

respectively

while the balance torque(BT) and water uptake(WU) decreases. These may be due to the increased surface activity and enhanced hydrophobicity of the WSPthe by AT. After alkalli treatment

if the WSP was modified by BA or SA again

TS

FS

IS and Ti of WSP/PP-CM can be increased while BT decreased. After alkalli treatment

if the WSP was modified by BA and SA together again

TS

FS

IS and Ti of WSP/PP-CM can be increased by 41.21%

32.02%

38.68% and 35.7℃ while BT decreased to 9.7N· m. The hydrophobicity of the composites was better than that of the unmodified WSP/PP-CM

although the effect was less than that of AT alone.