Abstract: Modified lignin products, processes for making them, and their use to produce rigid polyurethane or polyisocyanurate foams are disclosed. The processes comprise heating a lignin source with a nitrogen source and a starved concentration of a C1-C5 aldehyde to give a reaction mixture comprising a Mannich condensation product, neutralizing the reaction mixture, and isolating the modified lignin product. The process is performed at a mass ratio of lignin source to nitrogen source within the range of 1:1 to 1:5 and at a molar ratio of nitrogen source to C1-C5 aldehyde within the range of 3.5:1 to 1:1. Polyol blends and performance additives that contain the modified lignin products are described. Rigid foams that process well and incorporate up to 60 wt. %, based on the amount of polyol component, of the modified lignin contribute to excellent flame retardancy and low-temperature R-value performance.

Abstract: Modified lignin products, processes for making them, and their use to produce rigid polyurethane or polyisocyanurate foams are disclosed. The processes comprise heating a lignin source with a nitrogen source and a starved concentration of a C1-C5 aldehyde to give a reaction mixture comprising a Mannich condensation product, neutralizing the reaction mixture, and isolating the modified lignin product. The process is performed at a mass ratio of lignin source to nitrogen source within the range of 1:1 to 1:5 and at a molar ratio of nitrogen source to C1-C5 aldehyde within the range of 3.5:1 to 1:1. Polyol blends and performance additives that contain the modified lignin products are described. Rigid foams that process well and incorporate up to 60 wt. %, based on the amount of polyol component, of the modified lignin contribute to excellent flame retardancy and low-temperature R-value performance.

Abstract: Modified lignin products, processes for making them, and their use to produce rigid polyurethane or polyisocyanurate foams are disclosed. The processes comprise heating a lignin source with a nitrogen source and a starved concentration of a C1-C5 aldehyde to give a reaction mixture comprising a Mannich condensation product, neutralizing the reaction mixture, and isolating the modified lignin product. The process is performed at a mass ratio of lignin source to nitrogen source within the range of 1:1 to 1:5 and at a molar ratio of nitrogen source to C1-C5 aldehyde within the range of 3.5:1 to 1:1. Polyol blends and performance additives that contain the modified lignin products are described. Rigid foams that process well and incorporate up to 60 wt.%, based on the amount of polyol component, of the modified lignin contribute to excellent flame retardancy and low-temperature R-value performance.