Research On The Plasticizing Behavior And Properties Of Silicone Powder On Polyarylene Ether Nitrile Composite Material Peparation

Polymer dielectric materials have been widely applied in capacitor devices due to their light weight and low cost.Polyarylene ether nitrile(PEN)has good mechanical strength,thermal stability and chemical inertness,but its dielectric constant is relatively low,and usually requires co-blended conductive fillers to improve the dielectric constant.However,the addition of conductive fillers leads to an increase in the viscosity of the material.Industry usually selects plasticizers to improve the processing fluidity of materials,but traditional liquid plasticizers are prone to migration in the process of product use,significantly reducing the stability of product performance.As a solid lubricant with the advantages of high temperature resistance and safety and environmental protection,silicone powder solves the migration problem of liquid plasticizers and has important applications in the processing and molding of polymer materials.In this thesis,the effect of silicone powder on the plasticizing behavior and properties in the preparation of high dielectric polyaryl ether nitrile composites was investigated using polyaryl ether nitrile as the matrix resin.Firstly,to investigate the plasticizing behavior of silicone powder on PEN,PEN/silicone powder composite films were prepared by solution blending method.The rheological results showed that the silicone powder acted as a plasticizer for PEN,and the addition of the appropriate amount of silicone powder reduced the melt viscosity and increased the elongation at break of the material.Themal tests showed that the PEN/silicone powder composite films had comparable high temperature resistance to PEN,and the initial decomposition temperature was higher than 500 ℃.Thermal decomposition kinetic calculations show that the expected service life of the PEN/silicone powder composite film loaded with 1 wt% silicone powder is 6.7 years at300 ℃ service temperature with 5% weight loss.Secondly,to investigate the plasticizing behavior of silicone powder on PEN composites,MWCNTs and GO were used as a functional filler to improve the dielectric constant of the material,and silicone powder was used as a plasticizer to improve the processing fluidity of the material and the compatibility between the filler and the polymer matrix.The tests showed that the introduction of silicone powder improved the overall properties of the composites,including good thermal and mechanical properties,better flowability,and better compatibility and processability.In addition,the introduction of silicone powder improves the compatibility between the polymer matrix and the carbon nanomaterials.Finally,in order to effectively improve the dielectric constant and processing fluidity of the material,GO-silicone powder materials were prepared using the carboxyl groups on the GO surface and the amino groups of the hyperbranched polymer functionalized silicone powder.The PEN/GO-silicone powder composite films with different GO-silicone powder contents were prepared by cast film formation method.The analysis of the rheological results showed that the viscosity of the PEN/GO-silicone powder composite film with 1 wt% filling was lower than that of the pure PEN film,indicating that the GO-silicone powder had a plasticizing effect on PEN.The dielectric test results showed that the dielectric constant of the PEN/GO-silicone powder composite film with 4 wt% filler content reached 15.9 at 1 k Hz,which is twice as high as that of PEN/silicone powder/GO in Chapter 3.And the amount of GO in the PEN/GO-silicone powder composite film is lower,which is more cost effective.the PEN/GO-silicone powder composite film maintains comparable temperature resistance to PEN.