Institute for Color Science and Technology (ICST) Progress in Color, Colorants and Coatings 2008-2134 19 4 2026 10 01 Influence of Alkaline Pretreatment on the Reactive Dyeing Performance of Pineapple Leaf Fiber 457 465 82169 10.30509/pccc.2026.167702.1463 EN M. Mahedi Hasan Department of Apparel Engineering, Textile Engineering College, Begumganj, Noakhali, P.O. Box: 3831, Bangladesh Md. R. Rahman Department of Wet Process Engineering, Textile Engineering College, Begumganj, Noakhali, P.O. Box: 3831, Bangladesh A. Nur Uddin Department of Wet Process Engineering, Textile Engineering College, Begumganj, Noakhali, P.O. Box: 3831, Bangladesh Md. A. Hossain Department of Apparel Engineering, Textile Engineering College, Begumganj, Noakhali, P.O. Box: 3831, Bangladesh 0009-0004-9861-1957 A. Sayed Department of Apparel Engineering, Textile Engineering College, Pabna, P.O. Box: 6600, Bangladesh Journal Article 2025 10 22 This study evaluates the influence of alkaline pretreatment on the reactive dyeing performance and color fastness behavior of pineapple leaf fiber (PALF). Raw PALF extracted from Ananas comosus leaves was chemically treated with NaOH at concentrations of 3%, 5%, and 7% (w/v). This pretreatment removes non-cellulosic constituents and enhances cellulose accessibility. Microscopic analysis confirmed a transformation from coarse, fragmented structures to more individualized fibrillar networks following alkalization. Reactive dyeing using Fucozol Red UCX, Fuco Blue FSR, and Fucozol Navy/Blue NBF was performed under controlled salt, alkali, and temperature conditions. Fastness properties, including rubbing, perspiration, water, washing, and artificial saliva, were assessed according to ISO 105-X12, BS EN ISO 105-E04, BS EN ISO 105-E01, BS EN ISO 105-C06, and GB/T 18886. Dyed PALF exhibited predominantly high fastness ratings (4-5), with only minor reductions in wet rubbing and staining on polyamide and cotton. pH analysis showed a shift from 7.4 to 7.0 after dyeing. It indicates effective neutralization and maintenance of skin-compatible conditions. Overall, alkaline pretreatment significantly improved PALF's morphological uniformity, dye uptake, and fastness stability, demonstrating its suitability as a sustainable textile fiber for coloration applications. https://pccc.icrc.ac.ir/article_82169_7484af7fa92f04d087efeaa1807fb233.pdf