Abstract
PLA/SiO2 nanocomposites (PLAS) were prepared by premixing in chloroform solution and then melt extrusion. SiO2 were surface grafted via ring-opening polymerisation of L-Lactide before blending. Crystallisation and rheological properties of PLAS were investigated as a function of SiO2 content. It was identified from differential scanning calorimetry cooling plots that the addition of SiO2 could improve crystallisation rate and relative crystallinity of PLA. Meanwhile, SiO2 had affected rheological properties of PLA. Pure PLA and PLAS were both typical shear-thinning fluid, and shear viscosity of PLAS was higher than pure PLA. In dynamic sweep test, the linear viscoelastic regions with critical strains of PLAS decreased with the increasing SiO2 content compared with pure PLA. The G′, G″ and tan δ versus ω of PLAS were all improved. The results of rheological tests indicated that the addition of SiO2 had effect on the structure of PLA molecular chain and had formed network structure in PLA matrix.
Acknowledgement
This work was supported by the Fundamental Research Funds for the Doctoral Graduate (Grant No. JUDCF11035).