A series of styrene–acrylonitrile (SAN) copolymer nanoparticles were prepared by grafting
styrene–acrylonitrile from both aggregated silica and colloidally dispersed silica nanoparticles using
atom-transfer radical polymerisation (ATRP) in mini emulsion system. The grafted polymer silica
nanoparticles were characterised using transmission electron microscopy (TEM), and gel permeation
chromatography (GPC).The thermal and physical ageing behaviour of the nanocomposites have been
examined by differential scanning calorimetry (DSC).The addition of silica nanoparticles to PSAN can
influence its thermal and aging properties. Grafting PSAN-aggregated silica revealed considerable in-
crease in the glass transition temperature, whereas colloidally silica nanoparticles showed only a marginal
improvement. Additionally, while dispersing PSAN in colloidal and aggregated silica accelerated physical
ageing, grafting to aggregated silica significantly reduced ageing rates.
د. المهدي محمد المكي | Dr. Mahdi Mohammed Almaky | 9780