Preparation And Gas Adsorption Properties Of Porous Organic Polymers

Porous organic polymers,which combine the characteristics of "porous" and"polymer" are widely used in the fields of carbon capture,clean energy storage,catalysis,photoelectric materials and so on.However,large-scale preparation of porous organic materials with controllable structure and excellent performance is still a long-term goal.Therefore,the structure design and gas adsorption properties of four porous materials,such as coumarone-indene resin based hyper-crosslinked polymer,ferrocene based hyer-crosslinked polymer,polyisocyanate porous polymer and porous carbon materials,are studied in this thesis.The main contents are as follows:(1)The hyper-crosslinked microporous organic polymer is successfully prepared by using cheap coumarone-indene resin as building blocks and chloroform as crosslinker and solvent.The hard skeleton and high degree of crosslinking endow the materials with high thermal stability and acid and alkali stability.The porous structure of polymers can be adjusted by changing the amount of catalyst.A maximum surface area of 966 m2·g-1 is achieved.In addition,a large number of heteroatoms are doped into porous frameworks,which further enhance the interaction between specific sorbate molecule and adsorbent.Therefore,optimal structural and chemical properties endow the new coumarone-indene resin-based HCPs with decent gas storage capacity(14.60 wt%at 273 K/1 bar for CO2;1.18 wt%at 77.3 K/1 bar for H2).Considering the low cost monomer,the outstanding gas sorption performances,and the facile preparation strategy,these porous polymers are promising candidates for clean energy and environmental applications.(2)The iron-doped hyper-crosslinked porous polymer is prepared by using ferrocene as the building block,FDA as the crosslinker,and methylsulfonic acid as the acatalyst.Iron content of Fe-HCP3 is 13 wt%according to TG analysis.SEM and N2 sorption isotherms demonstrate the hierarchical pore structure in the material.The micropores are mainly concentrated at 1.2 nm,and mesopores are mainly concentrated at 2～10 nm.The influence of FDA dosage on crosslinking degree and pore structure of hyper-crosslinked polymers is further studied.The highest specific surface area is 1245 m2 g-1,and the pore volume is 1.01 cm3 g-1.The CO2 adsorption of ferrocene based hyper-crosslinked porous polymer reaches 9.4 wt%(273K/1 bar)and 5.5 wt%(298 K/1 bar).High CO2 adsorption is mainly ascribed to the high specific surface area and the existence of iron atoms in polymer frameworks.(3)We select commercial phenyl cyanates as building blocks and prepare a series of polyisocyanate crosslinking networks by trimerization under the catalysis of PC-41.ctTTI is selected as precursor and mixed with the activator KOH.The reaction between KOH with the precursor at high temperature includes chemical etching,physical activation and carbon lattice expansion,which can greatly improve the specific surface area and pore volume.By adjusting the temperature and KOH dosage,porous carbons with different pore structure and chemical properties can be obtained.The maximum specific surface area of 2341 m2 g-1 and pore volume of 1.04 cm3 g-1 are obtained.ctTTI and NPC-2-700 have the CO2 adsorption capacity of 14.7 wt%and 30.2 wt%(273 K/1 bar),respectively.The high CO2 capacity is attributed to the abundant small pore structure of porous materials and basic sites.H2 and CH4 adsorption for NPC-2-700 can reach 2.7 wt%(77.3 K/1.13 bar)and 3.8 wt%(273 K/1.13 bar),respectively.Therefore,polyisocyanate polymers and porous carbons derived from them have potential application in CO2,H2 and CH4 storage.