Through the ring-opening polymerization of L-lactide initiated by hydroxyl groups on the surface of HNTs using stannous 2-ethylhexanoate as catalyst

halloysite nanotubes surface-grafted with poly(L-lactic acid) (PLLA) segments (g-HNTs) were synthesized.The compositions and morphologies of the modified and unmodified HNTs were observed by Fourier transformation infrared (FTIR)

thermal gravimetric analysis (TGA) and transmission electron microscopy (TEM).Then

a series of PLLA

PLLA/HNTs and PLLA/g-HNTs nanofiber membranes were prepared by electrospinning

the influences of the spinning conditions on the morphologies of the nanofiber membranes were discussed

and the composition

micrograph

interfacial compatibility

tensile properties and cellular compatibility of the composite membranes were studied too.Results showed that the grafting percentage of PLLA segments on the surface of g-HNTs was 14.22% as the molar ratio of HNTs to L-lactide was 1:10.The tubular morphology of HNTs changed little after surface grafting

and g-HNTs can easily disperse in anhydrous ethanol.The voltage and the feed rate have effects on the morphology of fiber membranes

when the voltage was 15 kV and feed rate was 1 mL/h

the diameter of the electrospinning fiber was relatively uniform.The dispersion and interfacial compatibility of g-HNTs in PLLA matrix were superior to those of pristine HNTs

when the content of g-HNTs increased up to 40 wt%

the fiber micrograph of the PLLA/g-HNTs composite membranes continues to remain good

and continuous and relatively uniform fiber can be got.With the content of HNTs and g-HNTs increased

the tensile strength and modulus increased first and then decreased

as the filler content was 5 wt%

the highest tensile strengths and moduli were obtained for both of the PLLA/HNTs and PLLA/g-HNTs composite nanofiber membranes.However

the tensile strength and modulus of the PLLA/g-HNTs composite nanofiber membranes were always higher than those of PLLA/HNTs composite nanofiber membranes at all filler contents due to the good adhesive strength between the g-HNTs and PLLA matrix.The results of 3T3 cells culture in vitro indicated that the cellular compatibility of the PLLA/g-HNTs composite nanofiber membranes is very good

and better than that of pure PLLA and PLLA/HNTs nanofiber membranes.