Perfluorinated polymers are of high scientific and technological interest owing to their unique characteristics.However

their utilization is limited due to their poor cohesiveness

film-forming properties and high cost.When perfluorinated polymers are incorporated with polyacrylate

remarkable properties are exhibited with higher performance price ratio; that is

oil and water repellency of the former is unmitigated while the mechanical strength and cohesiveness of the latter are retained.As an inexpensive functional component

incorporated silica can shield polymeric matrix from the UV

while reinforcement and improved thermal stability are achieved

as well as better rinse-resistance

perdurability and self-cleanness effects. In this paper

nano-silica and poly(MMA-co-nBA-co-FA) were combined with covalent bonds.Not only extraordinary properties derived from each individual component were retained

but also a more intimate cooperation was provided between the twos

through an environment-friendly method. At first

the monodisperse silica was prepared in ethanol according to the well-known Stober procedure

followed by modification via addition of γ-methacryloxy propyltrimethoxysilane (MPS).Then

the nano-silica/poly(MMA-co-nBA-co-FA) hybrid emulsion was prepared via insitu emulsion polymerization in the presence of MPS-grafted silica. The chemical compositions and morphologies of both nano-silica and silica/poly(MMA-co-nBA-co-FA) nanocomposites (NPs) were characterized by Fouriertransform infrared (FT-IR) spectrometry and transmission electron microscopy (TEM)

respectively.From TEM images

it was obvious that uniform spherical nano-silica was obtained

with average diameter of 20 nm.FT-IR effectively proved the occurrence of MPS-grafting reaction.According to the amount of MPS added

the MPSgrafted density of nano-silica was determinated as 0.1716 μmol/m2. Off-centre core-shell structures of silica/poly(MMA-co-nBA-co-FA) NPs were confirmed by TEM images.Approximately 50% of NPs had more than one single core due to the congregating of smaller particles when the diameters of the core were not larger than 100 nm.Under a low MPS-grafted density

not all of monomers were polymerized and connected with MPS on the grafted silica

and most of the polymer chains were twisted and absorbed around the core particles

followed by copolymerization with polymer layer copolymerized with MPS

resulted in an off-centre core-shell structure ultimately. Thermal stability of silica/poly(MMA-co-nBA-co-FA) NPs was studied via thermal gravimetric analysis (TGA).The results showed that higher initiative decompose temperature was achieved with more nano-silica incorporated

which implicated the successful encapsulation of silica into NPs

as well as enhanced thermal stability. The surface properties of the latex films produced from silica/poly(MMA-co-nBA-co-FA) NPs were also investigated by contact angle method and water absorption measurements.Obviously

the incorporation of silica and FA contributed to degressive surface-free energy

with a minimum value of 9.8 mN/m.Similarly

water absorption ratio decreased with increasing contents of nano-silica and FA.What worth noting was the abnormal polar and disperse component of surface-free energy

which might be attributed to nano-silica’s incorporation and distribution while film-forming. Besides these

the kinetics of in situ emulsion polymerization

in which MPS-grafted silica with a low grafted density was introduced

had been investigated in details.The results can be summarized as follows: Rp∝［FA］0.25［SiO2］0.31［I］0.66［E］0.757 while ［SiO2］ 8.9 × 10-2 mol#8226;L-1

and Rp∝［FA］0.25［SiO2］-1.33［I］0.66［E］0.757 while ［SiO2］8.9×10 -2 mol.L -1.The overall activation energy of the polymerization was calculated to be 83.15 kJ/mol.