Abstract
Poly(L-lactic acid) (PLLA)/MWNTs composites were prepared by mixing solubilized PLLA with solutions of MWNTs treated by four kind of acids. Fourier transform infrared (FT-IR) spectra revealed that carboxyl groups were grafted to the surface of MWNTs. The water solubility showed that the MWNTs treated by HNO 3/H2O2 and HNO3/H2SO 4 could suspend in the air at room temperature for more than 100 days. Thermogravimetric analysis (TGA) showed that MWNTs treated by HNO3/H 2O2 and HNO3/H2SO4 obtained relatively high COOH content. Mechanical properties of composites showed that the Young's modulus of the carboxylated MWNTs/PLLA composites increased compared to the pure PLLA. Scanning electron microscopy (SEM) images of fracture morphology confirmed that the dispersion of carboxylated MWNTs was more homogeneous than the pristine MWNTs in polymer matrix. MWNTs treated by HNO3/H 2O2 could get more COOH group and less damage.
Get full access to this article
View all access options for this article.
