Hydrophobic and Durable Adhesive Coatings Fabricated from Fluorinated Glycidyl Copolymers Grafted on SiO2 Nanoparticles

To obtain durable adhesive, highly hydrophobic, and thermostable coatings, novel fluorinated glycidyl copolymers grafted on SiO2 nanoparticles were prepared by SiO2-Br initiating covalent adhesion of glycidyl methacrylate (GMA) and low surface free energy of dodecafluoroheptyl methacrylate (12FMA) via surface initiated atom transfer radical polymerization. In tetrahydrofuran solution, the obtained random-structured SiO2-g-(PGMA-co-P12FMA) behaves with 120 +/- 10 nm core-shell morphology as SiO2-core (110 +/- 10 nm) and (PGMA-co-P12FMA) shell (8 +/- 2 nm). The films cast by these core-shell particles reveal stronger hydrophobic surfaces (SAC = 114-119 degrees), higher resistance to water absorption (Delta m = 2478 ng.Hz(-1).cm(-2)), and harder viscoelasticity (Delta D/Delta f = -0.379) compared to the SiO2-g-PGMA film (SAC = 90 degrees, Delta m = 6153.7 ng.Hz(-l).cm(-2) , and Delta D/ Delta f = -0.271) due to the accumulated fluorine-rich surface and increased surface roughness. The introduction of antiaging P12FMA obviously improves the durability of adhesive strength of SiO2-g-(PGMA-co-P12FMA) (1.82 MPa) compared with that of SiO2-g-PGMA (decreased from 1.92 to 1.56 MPa) during the humidity thermal aging cycles. Meanwhile, SiO2-g-(PGMA-co-P12FMA) displays thermostability higher than that of both SiO2-PGMA and PGMA-co-P12FMA, attributed to the contribution of SiO2 and P12FMA. Therefore, it is believed that SiO2-g-(PGMA-co-P12FMA) could be an excellent potential candidate for highly hydrophobic and durable adhesive coatings.