Azo initiator 2

2′-azobis(isobutyramidine) dihydrochloride (AIBA) can be stably absorbed onto TiO2 particles by electrostatic action.The adsorbed AIBA can initiate the in situ anchoring of butyl acrylate from TiO2 particles surface

and thus poly(butyl acrylate)/TiO2 composite latex particles (PBA/TiO2) were prepared via in situ emulsion polymerization.It was found from centrifugation experiment and UV measurement that there was an upper limit of AIBA adsorbed on TiO2 particles surface

and its value was 0.084 mmol/g(relatived to the amount of TiO2) in pH=10 system.The adsorption of AIBA played a more important role both in polymerization behavior and in polymerization product.Only when the addition amount of AIBA was slightly less than the upper adsorption limit

the inhibition period was shorter

the polymerization rate and the monomer conversion were higher and the reaction stability were and the product stability were perfect.It was further proved by thermogravimetric analysis (TGA) and infrared spectrometry (FTIR) with soxhlet extraction experiment of PBA/TiO2 composite particles that 13.5% non-extraction poly(butyl acrylate) were anchored on TiO2 particles surface.It was also found from dynamic light scattering (DLS) that part of TiO2 softaggregation had been disaggregated stably

and both the dispersion and dispersion stability of TiO2 particles in latex can be significantly improved because of the anchoring modification of TiO2 by PBA.This action resulted from anchoring modification

in essence

was different from the reversible disaggregation action of ultrasonication treatment onto TiO2 softaggregation.Thus

this study is favourable for maintaining the good dispersion and dispersion stability of nanoscale inorganic particles in organic matrix during its application in the fields of coatings

painting

plastics

rubber

textile

and cosmetic.