| Surface acoustic wave (SAW) chemical sensor is a kind of vapor sensor that can operate in situ and in real-time. It has been used widely to detect explosives and chemical warfare agents because of its fast response with the signal and its small size, etc. The good performance of the SAW chemical sensor is depended both on the sensitive film and the coating method. In this paper, the synthesis and adsorption property of coating material, HFIP functionalized block copolymer PS-b-PMPHES, were studied.Cyclic siloxane oligomers were synthesized by condensation reaction, at room temperature, and the reaction time was 6h. The product was characterized by IR. Block copolymer PS-b-PMPHES with different molecular weights was synthesized by anionic ring-opening polymerization, and was characterized by IR and GPC, and the viscosity average molecular weight was evaluated by Ubbelohde viscometer. Effect factors on the molecular weight, such as the ratio of two monomers and [monomer]/[initiator] were studied. It comes to the conclusion that the molecular weight can achieve maximum, 58748, when [monomer]/[initiator] is 25.The target product was synthesized by Friedel-Crtafts between PS-b-PMPHES and hexafluoroacetone (HFA), also was characterized by IR, ion chromatograph, and hydroxyl content analysis. The optimum reaction conditions were also be studied, when CS2 was used as a reaction solvent, and finished in 10h, at 25℃,hydroxyl content and F content reached maximum.The HFIP functionalized block copolymer was coated on the SAW sensor piezocrystal by spin coating method. In the gas supply system, 2,4-dinitrotoluene (2,4-DNT) was used as simulation gas, and the responses of SAW sensor were tested. The influence of hydroxyl content in copolymer and copolymer concentration on adsorption property was also discussed.
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