Prepration Of Modified Polysuccinimide/PEBA Composite Membrane And CO₂ Separation Performance

Carbon dioxide produced by the combustion of carbon sources is one of the most important challenges facing the current world environment.Today,global warming may be the result of uncontrolled CO₂emissions.The global temperature continues to rise,making the living environment of humans and other living creature on earth worse gradually.However,carbon dioxide has a certain secondary use value.Therefore,the separation and capture of carbon dioxide has become particularly important,and the development of efficient carbon dioxide separation technology has become a research hotspot.In recent years,membrane separation technology has entered the industrial field and the scientific community with its characteristics of no phase change,good selectivity and strong adaptability.The compsite membrane can combine the characteristics of different membrane separation materials,and the membrane gas separation effect is better.Therefore,based on the design concept of the blend membrane,this study prepared two kinds of composite membranes with excellent performance by combining the structure and properties of polysuccinimide（PSI）and the properties of polyether copolyamide（PEBA2533）,and studied their water absorption,mechanical properties and carbon dioxide separation properties.In this paper,PAsp/PEBA2533 interpenetrating network hydrogel compsite membrane was prepared in situ with PEBA as the membrane matrix and PSI as the modifier.The introduction of PAsp not only improved the water absorption and mechanical properties of the membrane,but also improved significantly the CO₂separation performance of the membrane.The comprehensive performance of PAsp/PEBA interpenetrating network hydrogel composite membrane reached the best when the PSI dosage was 15 wt%.In terms of mechanical properties,the tensile strength and elongation at break were 12.01mpa and 725.81%,respectively,which were 21.80%and 43.42%higher than PEBA pure membrane.The results of the study on gas separation performance of PAsp/PEBA hydrogel composite membrane showed that the CO₂permeability coefficient reached 513 Barrer,and the selectivity of CO₂/N₂was 68,compared with the pure membrance,the selectivity of CO₂/N₂permeability coefficient increased by 214%and 240%respectively.PSI（MPSI）modified by arginine（LARG）and aminized SiO₂（NH₂-SiO₂）were used as the double modifiers and added to PEBA2533 membrane matrix as composite materials to prepare MPSI/PEBA/NH₂-SiO₂composite membrane in situ.The mechanical properties and CO₂separation properties of MPSI/PEBA/NH₂-SiO₂composite membrane were also studied.The addition of NH₂-SiO₂improved the gas separation performance of the membrane.Moreover,the introduction of PSI improved significantly the mechanical properties of the membrane.In this paper,the preparation conditions of the composite membrane were discussed when the gas separation performance was optimized.The results showed that the gas separation performance of MPSI/PEBA/NH₂-SiO₂composite membrane reached the best when the contents of NH₂-SiO₂when PSI and LARG were 5 wt%,15 wt%and 7 wt%respectively.