A porous polyurea material with rich amine groups was prepared through one-step precipitation polymerization of toluene diisocyanate and ethylenediamine

with acetonitrile or acetone as the polymerization solvent.By determination of the primary amine groups at ends of the polyurea molecules

it was concluded that 48 h of polymerization was needed for completing the polymerization.Effects of solvents

including acetonitrile

acetone and their mixtures at different mass ratios

on the properties of the porous polyurea were studied.The pore structure of the polyurea was characterized by BET and mercury intrusion

the morphology was observed by scanning electron microscopy and the crystallinity was characterized by X-ray diffraction.Results showed that the porous polyurea samples prepared in acetonitrile have higher specific surface area

higher pore volume and broader pore size distribution than those prepared in acetone.For the polyurea prepared in acetonitrile

both large and small pores ( 200 nm) were present

with a specific surface area of 153.2 m2g-1 and a pore volume of 3.5 cm3g-1; For that prepared in acetone

no small pores below 200 nm were detected by mercury intrusion and by BET

with therefore a much lower specific surface of 7.6 m2g-1 and pore volume of 1.2 cm3g-1.While in the mixture of the two solvents

the surface area and pore volume of the porous polyurea material decreased correspondingly

and the distribution of pore size narrowed with the increase in acetone amount in the binary mixture of the two solvents.The chemical structure of the polyureas was the same regardless of the solvent used in their preparation.XRD test demonstrates that partial ordered structure was present in the porous materials

owing to the heavy presence of hydrogen bonding

particularly the so-called ordered hydrogen bonding

formed between the urea carbonyl and the adjacent amide (NH)

which was supported by FTIR analysis.