Flame retardance-donated lignocellulose nanofibers (LCNFs) by the Mannich reaction with (amino-1,3,5-triazinyl)phosphoramidates and their properties

Fumiaki Ono; Takumi Okihara; Noboru Osaka; Noriyuki Nagaoka; Yuji Kameoka; Akira Ishikawa; Hironari Ooki; Takumi Ito; Daisuke Todome; Shinya Uemoto; Mitsuaki Furutani; Tsutomu Inokuchi; Kenji Okada

doi:10.1039/d1ra08716a

Flame retardance-donated lignocellulose nanofibers (LCNFs) by the Mannich reaction with (amino-1,3,5-triazinyl)phosphoramidates and their properties

RSC Adv. 2022 Jan 26;12(6):3300-3308. doi: 10.1039/d1ra08716a. eCollection 2022 Jan 24.

Authors

Fumiaki Ono¹, Takumi Okihara², Noboru Osaka³, Noriyuki Nagaoka⁴, Yuji Kameoka⁵, Akira Ishikawa⁵, Hironari Ooki⁶, Takumi Ito⁶, Daisuke Todome³, Shinya Uemoto¹, Mitsuaki Furutani¹, Tsutomu Inokuchi^{2

1}, Kenji Okada^{7

1}

Affiliations

¹ Okayama Biomass Innovation Creative Center 5301, Haga, Kita-ku Okayama 701-1221 Japan.
² Graduate School of Natural Science and Technology, Okayama University 3-1-1, Tsushima-naka, Kita-Ku Okayama 700-8530 Japan inokuchi@cc.okayama-u.ac.jp.
³ Faculty of Science, Okayama University of Science 1-1, Ridaicho, Kita-ku Okayama 700-0005 Japan.
⁴ Advanced Research Center for Oral and Craniofacial Science, Okayama University Dental School 2-5-1, Shikata-cho, Kita-ku Okayama 700-8558 Japan.
⁵ Marubishi Oil Chemical Co., Ltd 1-4-16, Dojimahama, Kita-ku Osaka 530-0004 Japan.
⁶ Gen Gen Corporation 74, Nakano Ori, Kamori Tsushima Aichi 496-0005 Japan.
⁷ Department of Life Science, Kurashiki University of Science & the Arts 2640, Nishinoura, Tsurajima Kurashiki 712-8505 Japan okada.kenji205@gmail.com.

Abstract

Nitrogen/phosphorus-containing melamines (NPCM), a durable flame-retardant, were prepared by the successive treatment of ArOH (Ar = Br _n C₆H_5-n , n = 0, 1, 2, and 3) with POCl₃ and melamine monomer. The prepared flame-retardants were grafted through the CH₂ unit to lignocellulose nanofibers (LCNFs) by the Mannich reaction. The resulting three-component products were characterized using FT-IR (ATR) and EA. The thermal behavior of the NPCM-treated LCNF fabric samples was determined using TGA and DSC analyses, and their flammability resistances were evaluated by measuring their Limited Oxygen Index (LOI) and the UL-94V test. A multitude of flame retardant elements in the fabric samples increased the LOI values as much as 45 from 20 of the untreated LCNFs. Moreover, the morphology of both the NPCM-treated LCNFs and their burnt fabrics was studied with a scanning electron microscope (SEM). The heat release lowering effect of the LCNF fabric against the water-based paint was observed with a cone calorimeter. Furthermore, the mechanical properties represented as the tensile strength of the NPCM-treated LCNF fabrics revealed that the increase of the NPCM content in the PP-composites led to an increased bending strength with enhancing the flame-retardance.