The synthesis and gas sensitive properties of a new polysiloxane material to organophosphate vapor

o-Allyl phenol was prepared with phenol,allyl bromide and anhydrone potassium carbonate as raw materials,via O-alkylation,Claisen rearrangement reaction.Then a new material-polymethyl [3-(2-hydroxy) phenyl]propyl siloxane(PMPS),which was sensitive to toxic organophosphate vapor,was synthesized by hydrosilyation using poly methyl hydrosiloxane and o-Allyl phenol.The PMPS was coated on quartz crystal microbalances(QCM) to investigate its gas sensitive properties to dimethyl methylphosphonate(DMMP) vapor,a stimulant of nerve agents,and other interfere vapors.The PMPS-QCM sensor responded linearly to DMMP vapor with a slope of 12.4×106Hz in the(5-70)×10-6 range.When tested with saturated vapors,the sensor was more than 6times sensitive to DMMP than to other interfere vapors.High selectivity of PMPS to DMMP was clarified.