Although nanocelluloses can be isolated from unbleached lignocellulosic fibers, the presence of residual lignin may result in nanocellulose products with dark colors, which limit their application in many fields. In this study, maleic acid pretreatment is utilized prior to the ball milling of raw sisal fibers to produce white or light-colored cellulose nanofibrils (CNFs). Pretreatment of the unbleached sisal fibers can facilitate the fibrillation of CNFs through the depolymerization of cellulose and the dissolution of non-cellulosic cell wall components and non-crystalline cellulose. After 2 h of maleic acid hydrolysis at 90 °C, the obtained light-colored CNFs shows a glucan content of 91.03 % and an average width of 12.35 nm. Self-standing films produced from the CNFs exhibit a high tensile strength of 92.73 MPa and an elastic modulus of 3.13 GPa. This study presents an innovative approach for using raw lignocellulosic fibers to produce light-colored CNFs without requiring a costly bleaching process.

尽管可以从未漂白的木质纤维素纤维中分离出纳米纤维素，但残留木质素的存在可能导致纳米纤维素产品呈深色，从而限制了其在许多领域的应用。在这项研究中，马来酸预处理在粗剑麻纤维球磨之前使用，以生产白色或浅色纤维素纳米纤维 (CNF)。未漂白剑麻纤维的预处理可以通过纤维素的解聚和非纤维素细胞壁成分和非结晶纤维素的溶解促进 CNF 的原纤维化。在 90°C 下马来酸水解 2 小时后，所得浅色 CNF 的葡聚糖含量为 91.03%，平均宽度为 12.35 nm。由 CNF 制成的自支撑薄膜具有 92.73 MPa 的高拉伸强度和 3.13 GPa 的弹性模量。