Preparation And Properties Of Phenolphthalein-based Poly (Arylene Ether Sulfone) Composites

Polymer-based inorganic composites combine the advantages of both polymers(good processability and good mechanical properties)and inorganic materials.An increasing number of polymer-based inorganic composites are applied in a wide range of fields for their unique properties emerging from the combination of excellent rigidity,thermal stability,mechanical strength and gas barrier of inorganic fillers and the polymer matrix with low weight,flexibility,and good processability.Phenolphthalein-based poly(arylene ether sulfone)(PES-C)as a novel engineering thermoplastics can be used as gas permeation membranes and water purification membranes for its outstanding mechanical properties,excellent thermostability and good chemical resistance.However,its application is limited to some extent owing to its defect of brittle fracture.The hybridation of PES-C and inorganic materials is a new way to solve the problem.In this work,a series of PES-C/inorganic composites have been designed and prepared in which perforative silica microspheres(PSM)and graphene oxide(GO)are used as fillers via solution mixing method.The main works of the present thesis are listed as follows:PSM,which exhibited abundant hierarchical meso/macro/penetrable porosity,were synthesized by phase separation and sol-gel transition coupled with emulsion method.Then taking the PSM as filler,a series of PES-C/PSM composites were prepared by solution mixing method and characterized by a combination of SEM、N2 adsorption-desoption isotherms、EDS、DSC、TGA.Morphological examination of the ultimate PES-C/PSM composites revealed that the dispersion of PSM in PES-C matrix was effective.The effects of PSM content on thermal and mechanical properties were studied,and the obtained results were discussed in terms of thermal degradation kinetics.Increasing PSM content resulted in a significant increase in both mechanical and thermal properties with only few percent of PSM loading.When 0.5 wt,% fillers were added into the PES-C matrix,the tensile strength was improved up to 80.35 MPa by 18.95%,and the breaking elongation was raised from 6.11% to 7.86% by 28.64%.In addition,thermal stability of composites was also positively affected.The activation energy of thermal degradation was increased from 211.41 to 256.44 kJ/mol.The high thermal and mechanical properties of the composites were mainly due to the homogeneous dispersion and PES-C molecule chain entanglement joint of PSM in the composites.By adopting secondary solution mixing process,a series of PES-C/graphene oxide(GO)were obtained.GO was prepared from natural graphite powder by chemical oxidation using the method developed by Hummers and the resulted composites were characterized by SEM,TEM,XRD,Raman,DSC,TGA,and tensile strength testing techniques.The results showed that GO layers could be dispersed homogenously in PES-C matrix in nanoscale.The addition of GO improved the toughness and thermal properties of PES-C obviously and the composites thermal degradation activation energy of composites could be turned by mass ratio of GO.Compared to neat PES-C,the elongation at break of composites containing 0.3 wt.% GO were measured to be 28.81%,enhanced by 348%,and the temperature for complete degradation was raised from 611.7 to 634.4 ℃ in air condition.Using the Kissinger method to evaluate the composites thermal degradation kinetic,the activation energy was increased from 211.41 to 247.70 kJ/mol when 0.1% GO was added.The activation energy of composites would decrease slowly resulted from increasing GO,and it might be less than neat PES-C when GO content was added more.