relation: https://khub.utp.edu.my/scholars/14496/ title: Production of rigid polyurethane foams using polyol from liquefied oil palm biomass: Variation of isocyanate indexes creator: Amran, U.A. creator: Salleh, K.M. creator: Zakaria, S. creator: Roslan, R. creator: Chia, C.H. creator: Jaafar, S.N.S. creator: Sajab, M.S. creator: Mostapha, M. description: 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. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. publisher: MDPI date: 2021 type: Article type: PeerReviewed identifier: Amran, U.A. and Salleh, K.M. and Zakaria, S. and Roslan, R. and Chia, C.H. and Jaafar, S.N.S. and Sajab, M.S. and Mostapha, M. (2021) Production of rigid polyurethane foams using polyol from liquefied oil palm biomass: Variation of isocyanate indexes. Polymers, 13 (18). ISSN 20734360 relation: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115166461&doi=10.3390%2fpolym13183072&partnerID=40&md5=80c9bc9491e4bf076c332e83110a4b20 relation: 10.3390/polym13183072 identifier: 10.3390/polym13183072