Preparation, Characterization And Application Of Siloxane Linking β-Cyclodextrin

Siloxane(DMS) is composed by the silicon and the oxygen.Due to longer length and larger bond angle of Si-O bond,it easily rotates.The intermolecular force gets weak,and the polymer is high elastic state.Polysiloxane has many outstanding physics,chemistry performances,like oxidative resistance,the weathering resistance,hydrophobicity as well as physiological inert and so on.Various function groups are introduced into siloxane molecules to endow some new functions and retain DMS characteristics.β-cyclodextrin(β-CD) is one kind of ring polysaccharides,it consist of seven glucopyranose unions,and each unit has three hydroxyl at different positions.They usually may divide into two groups due to different activity,namely high active -OH at 2,6 position and low active OH at 3 position.β-CD and DMS copolymer has widely been studied and used in the fixed phase of capillary gas chromatography for separation function of chiral compounds. The new application is always a hot topic.In this thesis,the linear silicon linking cyclodextrin(CDS) and four arm star silicon linking cyclodextrin(FSCD) were synthesized by usingβ-CD,allyl glycidol ether and hydro silicone as raw material through addition reaction of Si-H and C=C double bond,and etherfiacation reaction of epoxy propyl and cyclodextrin.FTIR,²⁹Si NMR,XRD,¹H NMR, ¹³C NMR,thin layer chromatograph and TG echniques were utilized to characterize their structures and thermal properties.New intumescent flame retardant(IFR) was was composed of CFA,CDS and ammonium polyphosphate(APP) for polypropylene(PP).The experimental results discovered when the loading of CDS in IFR is 6.25mass%,the limiting oxygen index reached 35%and vertical burning passed the UL-94 V0 level.The stretch strength,flexural strength and impact strength of intumescent flame retardant PP composites have been enhanced distinctly.TGA results indicated that the initial decomposition appeared earlier and the char residuce increased.SEM images demonstrated that the interface between PP and IFR is smooth and the char layer is close by contrasting with and without CDS samples.Inverse gas chromatography(IGC) technology was used to determine the surface properties of CD and FSCD.The dispersive free energy of FSCD is lower than CD and the Lewis acid number is higher than CD by introduction silicon to the polymer chain.Thermogravimetric analysis technology(TG) was used to study the thermal degradation reactions of CD,CDS and FSCD.Kissinger method and Ozawa method were used to compute the activation energy E,preexponential factor A and other parameters.The good liner relationship indicates that PP composites fit the most properble mechanism f(a)=(1-a)ⁿ perfectly.