Conservation and enhancement of naturally aged paper using bi-functionalized polyamidoamine (SiPAAOH)

Abstract PAAs can be further functionalized (hydroxylation and alkoxylation) by side chain substitution. In this study, we synthesized a SiPAAOH containing hydroxyl and siloxane groups based on the Aza-Michael addition reaction and applied it for reinforcement of aged paper. The results showed that the optimum conditions of SiPAAOH synthesis were as follows: the monomer molar ratio of APTES to EtA was 0.7:0.3, the solvent system for SiPAAOH reinforced aged paper was ethanol/water = 1:5 (v/v). The alkaline SiPAAOH could increase the pH of paper to 7.68, and to improve the amount of alkaline reserve to 200 mmol/kg. The whiteness and color difference of the treated paper were not significantly different from those of the untreated paper, and the mechanical properties of the paper were obviously improved. The results of contact angle and thermogravimetry showed that the SiPAAOH-treated paper was hydrophobicity and high temperature resistance.