Study On The Preparation Of Nano-Sb₂O₃/BEO-PBT Composites

The combinations of inorganic nanoparticles and polymers have been used to improve the properties of polymer materials and achieve the functionalization of composites,which has obtained a great success.The polymer-matrix nanocomposites have attracted considerable attention and worldwide interest due to their excellent physical and chemical characteristics including outstanding mechanical properties,electrical properties,barrier properties and flame-retardant properties.In order to obtain polymer/inorganic nanocomposites with excellent performance,the composites perfectly combined the stiffness,special functionality,thermal stability and dimensional stability of nanoparticles with the toughness,excellent processing properties and insulativity of polymer matrix,so that the composite can be applied in many fields.Notably,the process parameters of polymer reinforced by inorganic particles such as blending mode,processing mode,particle size and distribution,particle and polymer types also have a great influence on the physical and chemical properties of polymer-matrix nanocomposites.By a comparation between conventional preparation method and cryomilling technique,the cryomilling as a new-style preparation technique of composites is promising.In this study,the PBT matrix,brominated epoxy?BEO?and nano-Sb₂O₃ particles were selected.Nano-Sb₂O₃/PBT composite powders were prepared via different ball milling technologies including cryomilling and ambimilling.In the process of cryomilling,the changes of morphology and structure for single polymer and composite powders with polymer matrix and inorganic particles,the regularity of particle refinement and the mechanisms of dispersion and composites were systemically investigated by scanning electron microscope?SEM?,transmission electron microscope?TEM?,X-ray diffractometer?XRD?,laser diffraction particle size analyzer?LDPSA?and fourier-transform infrared spectroscopy?FT-IR?.Furthermore,the crystallization properties and thermal stability of cryomilled PBT and Nano-Sb₂O₃/PBT composite powders were studies by differential scanning calorimeter?DSC?and thermogravimetric analyzer?TGA?.The study determined that the two different molding methods were the optimal preparation process parameters for injection molding and hot compression molding,and used two different molding meth ods to prepare nano-Sb₂O₃/BEO-PBT composite materials.The mechanical properties and interaction mechanism of the prepared composites were studied.The main results are as follows:?1?PBT and nano-Sb₂O₃/PBT composite powders were prepared by cryomilling.The cryomilling can significantly improve the material refinement efficiency by using the embrittlement of PBT materials at low temperature and the addition of nano-Sb₂O₃particles.Cryomilling for 10 h,the PBT particles were reduced from the original 450?m to 11?m,and the addition of nano-Sb₂O₃ particles could accelerate the refinement of the composite particles.Cryomilling of nano-Sb₂O₃/PBT composite powder was performed for 10 h,and the average particle size obtained was 8?m.Cryomilling caused the breakage of polymer molecular chains,which led to a reduction in the molecular weight of PBT.And the semicrystalline structure of PBT changed into an amorphous structure.The addition of nano-Sb₂O₃ promoted the breakage of the PBT molecular chain and the reduction of the molecular weight of PBT.And the the molecular structure of PBT has no significant change.Cryomilling has a significant effect on the refinement,homogenization and compounding of n ano-Sb₂O₃/PBT composite powders.The nano-Sb₂O₃ particles in the composite powders can be dispersed well.?2?The results show that the nano-Sb₂O₃ had significant heterogeneous nucleation in PBT matrix due to its uniform dispersion by cryomilling,and the crystallization performance and thermal stability of nano-Sb₂O₃/BEO-PBT composite powders were improved.The composite powders prepared by cryomilling can greatly improve the crystallization ability of the matrix because of the homogeneous dispersion of nano-Sb₂O₃ particles.?3?The study determined two different molding methods and optimal process parameters.The effects of different molding processes on the mechanical properties of nano-Sb₂O₃/BEO-PBT composites have been studied.The mechanical properties of the composites prepared by the injection molding process are better than those of the hot press molding process.