Preparation And Properties Of High Heat Resistant PBT/PET Alloy

With the proposal of"energy saving and emission reduction",lightweight and the use of recycled materials have become important measures of energy saving and emission reduction.Plastics are often used to replace some metal parts because of light quality and good performance.However,with the development of society,the demand of market is becoming more and more diversified,and the single polymer can no longer meet the market demand.People hope to reduce the cost while meeting the performance requirements.The main purpose of this paper is to explore a low-cost and highly heat-resistant PBT/PET alloy.At first,pure PBT and PET were used for research,and at last,recycled PBT was used for experiment to reduce the production cost.The sources of the recycled materials are complex and extensive.In order to avoid the instability of the performance of the recycled materials,which might be take large errors to the experimental results,the pure materials PBT and PET will be used in the early stage of the experiment.Before the experiment of this paper,the previous studies were used to confirm that the heat deflection temperature was the highest and the heat resistance was the best when the ratio of PBT to PET was 90:10.Therefore,the ratio of PBT to PET was 90:10 for each subsequent experiment.Then explore the effect of different inorganic filler on the properties of PBT/PET,with using different inorganic filler?including nano silica,calcium sulphate,nano montmorillonite,sericite,nano barium sulfate?to filled PBT/PET system and testing the filling properties of PBT/PET system with the Vica-Heat deformation temperature tester,DSC,TGA,rotational rheometer,wide Angle X-ray spectrometer instrument and so on.It is found that the above inorganic fillers can improve the heat deformation temperature of PBT/PET system to varying degrees,improve the heat resistance of the composite materials,and generally improve the mechanical properties.The maximum heat deformation temperature of the systems filled with each inorganic filler are listed in the order from small to large:Nano montmorillonite?149.8??<Nano silica?158.1??=Calcium sulfate?158.1??<Sericite?169.9??<Nano barium sulfate?174.4??.Nanometer barium sulfate had the largest increase in heat deformation temperature of the system?174.4??,which was 21.8%higher than that of PBT/PET.In addition,the comprehensive mechanical properties of PBT/PET/BaSO₄ composite materials were enhanced,the crystallization temperature was increased,and the crystallinity was decreased.The comparison of PBT/PET filled with various inorganic fillers shows that the PBT/PET system filled with nano barium sulfate has the best performance and heat resistance.To reduce the production cost,nano barium sulfate was filled into the recycled PBT/PET to study its heat resistance,mechanical properties,crystallization properties,rheological properties and other properties.The study found that nano barium sulfate in recycling material of PBT/PET system?hereinafter referred to as the R-PBT/PET?can significantly improve heat resistance and comprehensive mechanical properties of composite materials,the heat deformation temperature can reach 177.0?,and due to the presence of aluminum acid ester coupling agent,the complex viscosity of the composite material decline slightly,the thermal stability of R-PBT/PET/BaSO₄composites performance is basically remain unchanged.To get a higher heat resistance and comprehensive performance,Disodium dihydrogen pyrophosphate?DSDP?was added into R-PBT/PET/BaSO₄ composites to suppress the transesterification between PBT and PET.After adding DSDP,the tensile properties of R-PBT/PET/BaSO₄ composites did not change significantly,the impact strength was improved,and the heat deformation temperature of the composite reached a maximum of 184.9?,the crystallization and melting temperature of the composite were basically unchanged due to the inhibition of transesterification.The crystallinity temperature of the R-PBT/PET/BaSO₄ composite with DSDP was slightly higher than that of the system without DSDP,the crystallization capacity of the blending system was less affected.In general,R-PBT/PET/BaSO₄ composite materials containing DSDP have the lowest cost,good heat resistance and comprehensive mechanical properties,which can reduce the production cost while meeting the performance requirements.