Synthesis and characterization of modified poly(aspartic acid) and its performance as a formaldehyde adsorbent

A modified poly(aspartic acid) (PASPTU) as an efficient formaldehyde adsorbent is successfully prepared by grafting poly(aspartic acid) (PASP) with threonine and urea. The graft copolymer is characterized by means of nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. Its formaldehyde adsorbent property is measured. The optimal adsorption process is as follows: synthesis temperature was 40 °C, molar ratio of PSI, threonine, and urea was 1:0.6:0.4 and adsorption time was 3.0 h. In above condition, the formaldehyde adsorbent efficiency of the copolymer was nearly 100% when the PASPTU dosage was 0.5 g. The Langmuir and Freundlich adsorption isotherms are used to study the adsorption process of formaldehyde. The findings show that PASPTU has excellent formaldehyde adsorbent efficiency.