Production of Rigid Polyurethane Foams Using Polyol from Liquefied Oil Palm Biomass: Variation of Isocyanate Indexes

Abstract

Development of polyurethane foam (PUF) containing bio-based components is a complex process that requires extensive studies. This work reports on the production of rigid PUFs from polyol obtained via liquefaction of oil palm empty fruit bunch (EFB) biomass with different isocyanate (NCO) indexes. The effect of the NCO index on the physical, chemical and compressive properties of the liquefied EFB-based PUF (EFBPUF) was evaluated. The EFBPUFs showed a unique set of properties at each NCO index. Foaming properties had affected the apparent density and cellular morphology of the EFBPUFs. Increasing NCO index had increased the crosslink density and dimensional stability of the EFBPUFs via formation of isocyanurates, which had also increased their thermal stability. Combination of both foaming properties and crosslink density of the EFBPUFs had influenced their respective compressive properties. The EFBPUF produced at the NCO index of 120 showed the optimum compressive strength and released the least toxic hydrogen cyanide (HCN) gas under thermal degradation. The normalized compressive strength of the EFBPUF at the NCO index of 120 is also comparable with the strength of the PUF produced using petrochemical polyol.

Recent advances in synthesis of polymers based on palm oil and its fatty acids

“…12(c) . 95 The normalized compressive strength of EFB-based PU foams with a 120 NCO index was comparable to PU foam from petrochemical-based polyol (as reference PU foam). Moreover, pictures of PU foams prepared using oil palm-based polyols are shown in Fig.…”

Valorization of Agricultural Rice Straw as a Sustainable Feedstock for Rigid Polyurethane/Polyisocyanurate Foam Production

“…The process of rice straw biomass liquefaction involves the degradation and decomposition of its lignocellulosic components through solvolytic reactions, as illustrated in Figure . The initial stages of liquefaction involve a rapid degradation of hemicellulose, lignin, and amorphous cellulose due to their amorphous structures, facilitating facile interaction with the liquefaction solvents. , In contrast, the liquefaction of crystalline cellulose proceeds at a slower rate, extending into later stages, attributed to its densely packed structure, which limits solvent accessibility. ,, During solvolysis, cellulose undergoes breakdown into glucose or smaller cellulose derivatives, which subsequently react with the liquefaction solvent, typically glycerol, to yield glycoside derivatives. Subsequently, these glycoside derivatives undergo reactions to form levulinic acid and/or levulinates. , It is worth noting that this mechanism follows the established reaction pathways for the liquefactions of other biomass reported in the previous studies. ,,− …”

Flame Retardant Behaviour and Physical-Mechanical Properties of Polymer Synergistic Systems in Rigid Polyurethane Foams

“…The structure and resulting performance of polyurethane foams are driven by the stoichiometry of the polymerization reaction, which is directly impacted by applied monomers, additives, their chemical composition, and the ratio between the polyols and isocyanates [ 10 ]. The amount of hydroxyl and isocyanate groups present in the system are essential for reactions leading to the generation of urethane bonds [ 11 , 12 ].…”