Study of the Relationship between Nanoparticles of Silica and Thermoplastic Polymer (TPU) in Nanocomposites

摘要

Nanosilicas with different silanol contents were obtained by treatment of hydrophilic nfumed silica with dimethyldichlorosilane. This treatment reduced the silanol content and nproduced the particle agglomeration of the nanosilicas. Thermoplastic polyurethane n(TPU) adhesives containing nanosilicas were prepared and characterized by FTIR nspectroscopy, differential scanning calorimetry (DSC), plate–plate rheology, dynamic nmechanical thermal analysis (DMTA) and transmission electron microscopy (TEM). It nwas demonstrated that addition of hydrophilic nanosilicas favored the degree of phase nseparation between the hard (i.e. isocyanate + chain extender) and soft (i.e. polyol) nsegments in the TPUs; the higher the silanol content on the surface of silica, the higher nthe degree of phase separation, and the crystallinity of the polyurethane (due to the soft nsegments) was also increased. Hydrogen bonds between the ester carbonyl groups in the nTPU and the silanol groups on the silica surface were created and more favored by nincreasing the silanol content.