Study On The Blending System Of Polymer With Powder

For a long time,the amount of powder added to polymers has been empirical,and there is no systematic theory or method to guide it.This project hopes that through the analysis of the properties of the polymer and the powder itself,can find the reason for the difference in the amount of addition,and these influencing factors can be related to the added amount.The solubility parameter proposed by Hildebrand is introduced to analogy the strength of the interaction between molecules.Based on the solubility parameter value of SiO₂measured in the literature,the Flory-Huggins action parameter^c12of polymer PP and SiO₂is calculated instead of polymer and polymerization.The compatibility parameters of the blending system were judged using the calculated Flory-Huggins action parameter^c12and the critical value（^c12）_cwhen the system began to phase separate,it shows that PP and SiO₂ are completely incompatible systems.Based on Schneie’s application of the GEE equation to determine the compatibility of polymer blends,the enthalpy of blending in the PP/SiO₂blending system was calculated and compared with the critical value.Compatibility is calculated by the blending ratio,and the mass fraction can be used to judge the compatibility of the polymer powder blending system,it shows that PP and SiO₂are completely incompatible systems.The effects of the solubility parameters of the polymer matrix,the electronegativity of the powder particles,the size,and the acid-base effect of the surface treatment agent on the amount of powder added in the blend system were analyzed.Based on the analysis data,MATLAB software was used to fit the empirical formulas of PP/SiO₂,PET/SiO_2,PP/Ca CO_3,PET/Ca CO_3,PP/MMT and PET/MMT in different blending systems.The relationship between the addition amount of different powders when they are well dispersed in different polymers is related to the solubility parameters of the polymer,the electronegativity of the powder particles,the size and the surface treatment.The PP/SiO₂ blending system was selected to experimentally verify the fitted formula.Use silane coupling agent KH570 and stearic acid modifier to modify nano-SiO₂,blend with PP,and observe its blending effect with various characterization methods,such as SEM,infrared spectrum,DSC,melt index,etc..At the same time,the data in other literatures of each system were substituted into the fitted expressions for verification.The experimental results and other literature data verifications show that the fitted formula has certain accuracy.