摘要

Composite emulsions of waterborne polyurethane (WPU) with multiwalled carbon nanotube (MWCNTs) have been synthesized successfully. Waterborne polyurethane emulsions were synthesized from the alcoholysis products of waste poly(ethylene terephthalate) (PET). Carbon nanotubes were treated with concentrated acid, to have better compatibility in waterborne polyurethane. Thermal properties show that the introduction of carbon nanotubes enhances the thermal stability of WPU matrix. However, a further increment of the content of MWCNTs from 0.3 to 0.5% causes a reduction. When the content of MWCNTs increases from 0.5% to 2%, the thermal stability of waterborne polyurethane samples enhances, which is related to the steric hindrance effect of MWCNTs. The dispersion of MWCNTs is the best for waterborne polyurethane with 0.3% MWCNTs. X-ray diffraction tests show the introduction of MWCNTs does not change the crystallographic structure of the WPU matrix. Visual examination, TEM images, and UV/Vis absorption spectrum prove that partial carbon nanotubes have been dispersed homogenously in the waterborne polyurethane matrix. The dispersion of MWCNTs is the worst for waterborne polyurethane sample with 2% MWCNTs in three samples. Water absorption tests show that carbon nanotubes can decrease the water absorption. POLYM. ENG. SCI., 58:2149-2155, 2018.