Synthesis And Application Of Polyacrylate/Hollow Silica Composite Leather Finishing Agent For Leather Finishing

Due to the chemical and light stability, transparency and good film-formingproperties, the leather finishing agent acted by polyacrylate film is the mostwidely used in leather industry. However, the water vapor permeability of purepolyacrylate leather finishing agents is very poor. Hollow silica (SiO2) spheres,which have lower density, high hardness, larger specific area, good thermalstability, special hollow core and other excellent properties, are widely used inenvironmental protection, drug delivery system, electronic and other fields.However, hollow SiO2spheres as inorganic additives to improve the water vaporpermeability of leather finishing agent are no reported.In this research, the hollow SiO2spheres with different morphology wereprepared by hard template method, and used in polyacrylate leather finishingagent by physical blending or in-situ emulsion polymerization. Thepolyacrylate/hollow SiO2spheres composite leather finishing agents with betterwater vapor permeability were obtained.1. The PS spheres were prepared via in-situ emulsion polymerization. Theeffects of content and kind of emulsifier, content of initiator and content of St onPS spheres size were investigated. The TEM and DLS were used to characterizethe morphology and size of PS spheres. The results showed that the size andmorphology of obtained PS spheres were neat and could be controlled in thismethod. Also, the effects of initiator and St content on PS spheres size werefeeble. However, the kind and content of emulsifier were obvious. The size of PSspheres was15~100nm when the CTAB was acted as emulsifier. In contrast, thesize is150~500nm when the PVP was used.2. The hollow SiO2spheres with different morphology, size and shellthickness were prepared using PS as templates, which the TEOS was used asSiO2precursor. The effects of PS size and TEOS content on hollow silica spheres morphology were investigated. These hollow SiO2were characterized by TEM,SEM, BET, FT-IR and XRD. The results illustrated that the hollow SiO2withdifferent morphology, hollow size and shell thickness were obtained, and thereare many small holes on the shell. Also, the craystal of hollow SiO2spheres shellis amorphous. The polyacrylate/hollow SiO2spheres composite leather finishingagents were prepared by physical blending and in-situ emulsifier polymerization.The hollow size, shell thickness and content of hollow SiO2spheres on watervapor permeability were investigated. The results illusterated hollow SiO2spheres could obviously increase the water vapor permeability of polyacylateleather finishing agent.3. The mesoporous hollow SiO2spheres with different hollow size, shellthickness and mesoporous size were prepared using PS as templates, which theTEOS/VTES was used as SiO2precursor. The effects of size of PS spheres, theratio and content of TEOS/VTES on hollow silica spheres morphology wereinvestigated. These mesoporous hollow SiO2were characterized by TEM, SEM,BET, FT-IR. The illustrated that the mesoporous hollow SiO2with differenthollow size, shell thickness and mesoporous size were obtained, and there aremany mesoporous structures on the shell. The polyacrylate/mesoporous hollowSiO2spheres composite leather finishing agents were prepared by physicalblending and in-situ emulsifier polymerization. The hollow size, shell thickness,mesoporous size and content of hollow SiO2spheres on water vapor permeabilitywere investigated. The results illusterated mesoporous hollow SiO2spheres couldobviously increase the water vapor permeability of polyacylate leather finishingagent. The mesoporous hollow silica spheres are more conducive to increasingthe water vapor permeability of composite leather finishing agents than hollowsilica spheres.