Suppressing aggregation of quinacridone pigment and improving its color strength by using chitosan nanofibers

Yasuko Saito; Shinichiro Iwamoto; Yuki Tanaka; Naoya Hontama; Takashi Endo

doi:10.1016/j.carbpol.2020.117365

Suppressing aggregation of quinacridone pigment and improving its color strength by using chitosan nanofibers

Carbohydr Polym. 2021 Mar 1:255:117365. doi: 10.1016/j.carbpol.2020.117365. Epub 2020 Nov 5.

Authors

Yasuko Saito¹, Shinichiro Iwamoto², Yuki Tanaka³, Naoya Hontama⁴, Takashi Endo⁵

Affiliations

¹ Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, 739-0046, Japan. Electronic address: saitou.y4@aist.go.jp.
² Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, 739-0046, Japan. Electronic address: s.iwamoto@aist.go.jp.
³ Sanyo Color Works, Ltd., Hyogo, 670-0966, Japan. Electronic address: bunseki@sanyocolor.jp.
⁴ Sanyo Color Works, Ltd., Hyogo, 670-0966, Japan. Electronic address: hontama@sanyocolor.jp.
⁵ Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima, 739-0046, Japan. Electronic address: t-endo@aist.go.jp.

PMID: 33436198
DOI: 10.1016/j.carbpol.2020.117365

Abstract

Quinacridone, a red pigment, is prone to aggregation, which results in undesirable color changes. Cellulose nanofibers (NFs) have been reported to adsorb quinacridone and suppress its aggregation. In this study, we investigated the potential of chitin and chitosan NFs which possess acetoamide and amino groups, as a quinacridone dispersant. Chitosan NFs, obtained by fibrillation using high-pressure homogenizer, adsorbed more quinacridone than cellulose NFs. SEM observations showed that chitosan NFs inhibited the aggregation of quinacridone, but chitin NFs did not. NMR analysis suggested the hydrogen bonding between chitosan NFs and quinacridone induced by the amino groups. The results indicated that the amino groups more facilitated the intermolecular interactions between NFs and quinacridone than the hydroxyl groups whereas the acetamide groups hindered them. Color measurements showed that the redness of quinacridone improved when cellulose or chitosan NFs were added. Chitosan NFs were found to be a novel candidate for quinacridone dispersants.

Keywords: Cellulose nanofiber; Chitosan nanofiber; Dispersant; NMR spectroscopy; Organic pigment; Quinacridone.