In this study, we report a new design to prepare polyimide–nanogold nanocomposites of high Au content and good thermal stability. The nanocomposites were prepared from the coupling agent (3-aminopropyltriethoxysilane, APS) capped poly(amic acid) (PAA–APS) and 3-mercaptopropyltrimethoxysilane (MPS) stabilized gold nanoparticles (MPS–Au). The Si–OR groups of MPS on the surface of MPS–Au provided further reaction with APS, hence the covalent bonds between PAA and MPS–Au were formed. PAA–Au was converted into PI–Au nanocomposite by a multiple-step baking. The results of particle-sized analysis show that the sizes of the synthesized MPS–Au from different MPS/Au mole ratios (2 and 0.5) are about 2 nm and 5 nm, respectively. FE-SEM images show that MPS–Au particles are dispersed well in the prepared nanocomposites and no large-scale aggregation occurs. TGA results indicate that the decomposition temperature of each nanocomposite prepared from its washed precursor is lower than that of APS-capped polyimide, but the temperature of maximum decomposed rate of each nanocomposite is higher than that of APS-capped polyimide. The results show the high thermal stability and application potentials of the prepared polyimide–nanogold nanocomposites.
Polymer Degradation and Stability 93(1), pp.109-116