Fundamental Research On Poly(Fluoroalkoxyphosphazenes) High Performance Elastomer

Chapter 1 After summarizing history, actuality and development of phosphazene compounds, their synthetic procedures, structure, performance and application in the field of elastomer were introduced in detail.Chapter 2 In chapter 2, several poly(fluoroalkoxyphosphazenes) substituted by 2,2,3,3,4,4,5,5-octafluoropentoxy and 2,2,2-trifluoroethoxy were synthesized. Reactions were carried out at room temperature (25℃) and at 67℃in tetrahydrofuran (THF) and were monitored by ¹H NMR and ³¹p NMR spectroscopy. The possible factors that influence side group replacement in poly(dichlorophosphazene) are discussed and the structure of poly(fluoroalkoxyphosphazenes) as a function of the reaction time,reaction temperature and inventory rating are examined.Chapter 3 a series of poly(fluoroalkoxyphosphazenes) containing a mixture of 2,2,3,3,4,4,5,5-octafluoropentoxy and 2,2,2-trifluoroethoxy substituents was synthesized. The series included polymers with 25-94% incorporation of the trifluoroethoxy substituent, as well as single-substituent polymers with 100% octafluoropentoxy or trifluoroethoxy side groups. The polymers were analyzed by multi-nuclear NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and were subjected to microtensile testing and DMTA testing. The variation in thermal and mechanical properties as a function of the side group ratios is discussed.Chapter 4 Mixed-substituent poly(fluoroalkoxyphosphazene) with unsaturated side group was synthesized. And the polymer was vulcanized by dicumyl peroxide as vulcanized agent. The polymers were subjected to tensile testing. The variation in mechanical properties as a function of the crosslink density is discussed.