Shang Jiao-Ping, Liang Pin, Peng Yun, Xu Ding-Feng, Li Yi-Bao
Engineering Research Center of Jiangxi Province for Bamboo-Based Advanced Materials and Biomass Conversion, College of Chemistry and Chemical Engineering, Gannan Normal University, Golden Campus, Ganzhou 341000, China.
Polymers (Basel). 2023 Mar 16;15(6):1475. doi: 10.3390/polym15061475.
Bleached bamboo pulp, as a kind of natural cellulose, has received significant attention in the field of biomass materials due to its advantages of environmental protection and the abundance of raw materials. Low-temperature alkali/urea aqueous system is a green dissolution technology for cellulose, which has promising application prospects in the field of regenerated cellulose materials. However, bleached bamboo pulp, with high viscosity average molecular weight (η) and high crystallinity, is difficult to dissolve in an alkaline urea solvent system, restraining its practical application in the textile field. Herein, based on commercial bleached bamboo pulp with high η, a series of dissolvable bamboo pulps with suitable η was prepared using a method of adjusting the ratio of sodium hydroxide and hydrogen peroxide in the pulping process. Due to the hydroxyl radicals being able to react with hydroxyls of cellulose, molecular chains are cut down. Moreover, several regenerated cellulose hydrogels and films were fabricated in an ethanol coagulation bath or a citric acid coagulation bath, and the relationship between the properties of the regenerated materials and the η of the bamboo cellulose was systematically studied. The results showed that hydrogel/film had good mechanical properties, as the η is 8.3 × 10 and the tensile strength of a regenerated film and the film have values up to 101 MPa and 3.19 MPa, respectively. In this contribution, a simple method of a one-step oxidation of hydroxyl radicals to prepare bamboo cellulose with diversified η is presented, providing an avenue for a preparation of dissolving pulp with different η in an alkali/urea dissolution system and expanding the practical applications of bamboo pulp in biomass-based materials, textiles, and biomedical materials.
漂白竹浆作为一种天然纤维素，因其环保优势和丰富的原材料，在生物质材料领域受到了广泛关注。低温碱/尿素水溶液体系是一种纤维素的绿色溶解技术，在再生纤维素材料领域具有广阔的应用前景。然而，漂白竹浆具有较高的粘均分子量（η）和结晶度，难以溶解于碱性尿素溶剂体系，限制了其在纺织领域的实际应用。在此，基于具有高η的商业漂白竹浆，采用在制浆过程中调节氢氧化钠和过氧化氢比例的方法制备了一系列具有合适η的可溶解竹浆。由于羟基自由基能够与纤维素的羟基发生反应，分子链被切断。此外，在乙醇凝固浴或柠檬酸凝固浴中制备了几种再生纤维素水凝胶和薄膜，并系统研究了再生材料性能与竹纤维素η之间的关系。结果表明，当η为8.3×10时，水凝胶/薄膜具有良好的力学性能，再生薄膜的拉伸强度高达101 MPa，薄膜的拉伸强度为3.19 MPa。本文提出了一种通过羟基自由基一步氧化制备具有多样化η的竹纤维素的简单方法，为在碱/尿素溶解体系中制备不同η的溶解浆提供了途径，并拓展了竹浆在生物质基材料、纺织品和生物医学材料中的实际应用。
