Aramid pulp treated with imidazolium ionic liquids as a filler in rigid polyurethane bio-foams

This article reports an aramid pulp (AP) treated with two ionic liquids (IL), namely 1-n-butyl-3-methylimidazolium chloride (C-4.Cl) and 1-carboxymethyl-3-methylimidazolium chloride (HO2C), and its use as a filler in reinforced rigid polyurethane foams (RPUF). The RPUF were incorporated with the treated AP at three weight fractions (c.a. 0.1, 0.5, and 1.0 wt%) and were produced by the free rising method. The results showed that the studied IL promoted a better interaction between the AP and the RPUF system, which increased the overall reactivity, imparting a higher cell anisotropy. This also yielded a positive effect in mechanical properties and thermal stability of the RPUF. Compared to the neat RPUF, outstanding increases of approximately 50 and 20% were achieved in compressive modulus and strength, respectively. In all, the use of IL promoted increased compatibility between matrix and reinforcement, especially that HO2C IL.

Automated summary

This study found that aramid pulp treated with two ionic liquids as a filler in reinforced rigid polyurethane foams improved overall reactivity and cell anisotropy, while enhancing mechanical properties and thermal stability of RPUF. The use of IL promoted increased compatibility between matrix and reinforcement, especially HO2C IL.