Preparation And Properties Of POSS/Poly(aryl Ether Ketone)Composites With Low Dielectric Constant

The rapid development of electronic science and technology continuously push the progress of related fields.As an important part of electronic components,electronic packaging materials have an important influence on the performance of electronic products.Electronic packaging materials can effectively protect the electronic components from the interference of external environment,to ensure the effective transmission of signal and the function is stable.Advent of a new generation of electronic products often tends to represent the functionalization of electronic components,more efficient and higher frequency.Under the trend of traditional packaging materials gradually cannot meet the requirements of ultra-large scale integrated circuit,that effective design to the preparation of excellent comprehensive performance of polymer encapsulation materials to replace traditional packaging materials become one of the highlights in the field of scientific research and application.Poly(aryl ether ketone)(PAEK)is a kind of special engineering material with aromatic structure,low dielectric constant,excellent thermal performance and well mechanical properties.In view of their excellent comprehensive performance which had been widely used in automobile,petroleum,aerospace and other fields,specific functional material of poly(aryl ether ketone)in many high-end technology had shown great potential application value.Through reasonable and effective design,poly(aryl ether ketone)can be reduced its dielectric constant but keeping its excellent thermal and mechanical properties so that it can meet the requirements of microelectronics packaging materials.Polyhedral oligomeric silsesquioxanes(POSS)is a kind of functional nanoparticles with hollow structure,in the fields of photoelectric materials,intelligent response materials have wide application.Based on their hollow structure,POSS can be introduced into polymer materials to lower the dielectric constants of materials also aroused the interest of many researchers.Many ways of introducing POSS into polymer materials had been designed;that POSS is introduced into the polymer material by covalent bond can improve its dispersity in the polymer material,and can effectively improve its compatibility with polymer materials.Two methods were adopted to prepare the composites of POSS/poly(aryl ether ketone)and the effect of POSS content and the different dispersion morphology of POSS on the dielectric properties,thermal properties and mechanical properties were discussed in detail.Firstly,by covalent bond method through the formation of amide bond between amino of POSS and carboxylic of poly(aryl ether ketone),POSS nanoparticles were grafted onto the side chain of poly(aryl ether ketone),and the matrix and composite materials structure were characterized and the effect of POSS on the dielectric properties,the thermal and mechanical properties of the composites were investigated.The results showed that POSS could be uniformly dispersed into poly(aryl ether ketone)by formation of covalent bonding between POSS and PAEK and the dielectric constants of the composites decreased with the content of POSS increasing in composites,when the mole content of POSS was 10%,the dielectric constant of composites reduced to 1.63,meanwhile,the composites still maintained good thermal performance and excellent mechanical properties.From this study,many literatures or reports,it is found that if only exist the polymer matrix and the nanoparticles in the composite materials,whatever nanoparticles are linked branches,anchored in the end,attached by hyperbranched method by covalent bonding or other ways,nanoparticles will be formed of about 10 nm nanoclusters in the composite materials and will not exist in the form of monodisperse.Generally,most of the individual nanoparticles are around 1~2 nm,the function efficiency of nanoparticles will be greatly reduced if the nanoclusters forming in the composite materials.So in this thesis,the POSS nanoparticles were firstly dispersed onto the graphene oxide with covalently grafting and the hybrid of POSS nanoparticles and the graphene oxide were compounded into the polymer matrix by solution blending,which improved the dispersion of POSS in composite materials and greatly improved the function efficiency of nanoparticles.The results indicated that the dielectric constant of the composites decreases with increasing the hybrid of POSS nanoparticles and the graphene oxide,when the mass fraction of hybrid was 3.0 wt%,the dielectric constant of the composites reduced to 2.01,the nanoparticles with little size could greatly improve the efficiency of nanometer by comparison,that was,with less mass fraction of nanoparticles in the composites could effectively reduce the dielectric constant of the composites,and the Young's modulus of composites had an obvious improvement.The research work in this thesis was carried out based on the POSS and poly(aryl ether ketone),POSS/poly(aryl ether ketone)composites with low dielectric constant were prepared through different ways.The properties of the composites prepared by different method were compared,and the results in this thesis are expected to provide some inspiration for the design and preparation of low dielectric constant materials or nanocomposite materials.