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以纳米微晶纤维素(NCC)为骨架,甲基丙烯酸六氟丁酯为单体,通过乳液接枝聚合合成新型表面施胶剂,并进行表面施胶的应用研究。考察乳化剂用量和含氟单体与NCC质量比对接枝率、接枝效率和单体转化率的影响;在较优条件下改性NCC接枝率、接枝效率、单体转化率分别为125.2%、27.7%、90.1%。通过红外光谱进行接枝前后NCC的官能团变化分析。通过纳米粒度仪分析了未改性/改性NCC的Zeta电位及粒径变化;结果表明,所得改性NCC在乳液体系中具有良好的稳定性;将其用于表面施胶,施胶处理后的纸张接触角能够达到120°,抗张指数较使用未改性NCC的纸张可提高26.4%,达到22.0 N·m/g。 相似文献
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以结构完整、分散性良好的纳米结晶纤维素(NCC)粉体为研究基体,采用有机官能团硅烷偶联剂GWB-1和GWB-2为改性剂分别对NCC进行改性,以提高NCC对脲醛树脂的浸润性,并对GWB-1、GWB-2的改性效果进行比较.结果表明,GWB-1、GWB-2引入的疏水性基用能够取代NCC的表面羟基,明显改善NCC对脲醛树脂的浸润性;GWB-2引入NCC表面的疏水性基团提供的空间位阻大于GWB-1,能够使NCC产生更好的浸润性. 相似文献
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《江苏造纸》2015,(1)
纳米纤维素晶体(NCC)可由可再生资源制备,并且具有诸多特性,近年来成为研究热点。本文应用PFI磨对竹子溶解浆预处理,用纤维素酶水解制备纳米纤维素晶体,研究了酶解时间、酶解温度、酶用量对纳米纤维素晶体产率的影响,采用正交实验优化了工艺参数。并用扫描电镜、激光粒度仪、傅里叶红外、热重对原料及NCC进行性能表征。结果表明:在酶用量8m L、酶解时间3d、酶解温度50℃的条件下,纳米纤维素晶体的产率最高,达到19.13%。PFI磨预处理及酶解均可细化纤维素,NCC的Z均粒径为375.5nm,所制备的NCC保持了原料的基本化学结构,NCC的热稳定性低于原料,但其热分解残余率增大。 相似文献
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纳米晶体纤维素(NCC)来源于最丰富的生物质资源--纤维素,是最有发展前景的材料之一。 NCC具有很多独特的特点,适合应用于新材料的开发,且来源丰富,环境友好可再生,其力学性能和纳米级尺寸使其应用范围非常广。NCC最有前景的一个应用是聚合物基质纳米复合材料。文章概述了这种新兴纳米复合材料的技术发展和应用,重点讨论了NCC材料未来发展中可能会遇到的挑战和机遇,以及NCC应用中存在的问题。 相似文献
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为探寻安全高效的可食性涂膜应用于柑橘保鲜,选取壳聚糖(chitosan,CS)和纳米纤维素(nanocrystal cellulose,NCC)两种天然材料进行复合,对红桔进行涂膜保鲜。首先制备了独立膜,考察了NCC对独立膜抗张性能和透过性能的影响;然后将NCC/CS复合涂膜用于红桔保鲜,考察其对红桔腐烂率和各项生理品质指标的影响。结果表明,NCC的添加有助于提高复合独立膜的抗张性能,降低其吸湿性。在红桔保鲜中应用时,相较于CS涂膜,NCC/CS复合涂膜可进一步降低红桔在贮藏期间的腐烂率,减少丙二醛的积累,有利于保持果实硬度,并维持其营养物质的含量。其中,NCC质量分数为6%的6NCC/CS复合涂膜对红桔的保鲜效果最为显著。 相似文献
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《印染》2015,(18)
利用硅氢化反应对含氢硅油进行改性,并协同纳米微晶纤维素(NCC)对棉织物进行拒水整理。通过测试淋雨性能和静态接触角,优化了有机硅的改性合成工艺,探讨了整理剂质量浓度、焙烘温度及NCC协同作用对拒水效果的影响。结果表明,当含氢硅油的含氢量为0.2%、碳碳双键/硅氢键的比例为1.2∶1、甲基丙烯酸十八酯/烯丙基缩水甘油醚物质的量比为9∶1时,制得的改性有机硅拒水效果最佳;当改性有机硅质量浓度为10 g/L、焙烘温度为160℃时,整理织物的拒水等级和静态接触角分别为85分和144.0°;当粒径为220 nm的NCC协同改性有机硅对织物进行拒水整理时,拒水效果显著提升,拒水等级和静态接触角分别为95分和146.8°,经SEM观察发现,NCC在织物表面形成了均匀的粗糙结构。 相似文献
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《造纸科学与技术》2017,(3)
以马铃薯淀粉为原料,在氧化剂次氯酸钠、交联剂六偏磷酸钠和助剂纳米纤维素(NCC)的作用下制备氧化交联马铃薯淀粉。并以此改性淀粉取代部分丁苯胶乳,探究其对涂料和涂布铜版纸性能的影响。研究表明:在马铃薯淀粉的氧化交联反应中,加入一定量的NCC能提高氧化交联马铃薯淀粉的羧基含量和交联度;涂料的黏度都随改性淀粉取代丁苯胶乳份数的增加而增加,并且当改性淀粉取代丁苯胶乳的份数不超过3份时,对涂料的黏度影响不大;含有一定量NCC的改性淀粉取代部分丁苯胶乳后的涂布纸,平滑度、阻隔空气能力、表面强度和抗水性都优于不含NCC的改性淀粉的涂布纸。并且当含有一定量NCC的改性淀粉取代丁苯胶乳的份数不超过3份时,涂布纸的白度、平滑度、阻隔空气能力和表面强度都优于全丁苯胶乳涂料的涂布纸。 相似文献
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Simultaneous Extraction of Carboxylated Cellulose Nanocrystals and Nanofibrils via Citric Acid Hydrolysis—Sustainable Route 下载免费PDF全文
Chao Liu HaiShun Du Guang Yu YueDong Zhang QingShan Kong Bin Li XinDong Mu 《造纸与生物质材料》2017,2(4):19-26
In this study, cellulose nanocrystals (CNC) with surface carboxylic groups were prepared from bleached softwood pulp by hydrolysis with concentrated citric acid at concentrations of 60 wt%~80 wt%. The solid residues from acid hydrolysis were collected for producing cellulose nanofibrils (CNF) via post high-pressure homogenization. Citric acid could be easily recovered after hydrolysis reactions through crystallization due to its low water solubility or through precipitation as a calcium salt followed by acidification. Several important properties of CNC and CNF, such as dimension, crystallinity, surface chemistry, thermal stability, were evaluated. Results showed that the obtained CNC and CNF surfaces contained carboxylic acid groups that facilitated functionalization and dispersion in aqueous processing. The recyclability of citric acid and the carboxylated CNC/CNF give the renewable cellulose nanomaterial huge potential for a wide range of industrial applications. Furthermore, the resultant CNC and CNF were used as reinforcing agents to make sodium carboxymethyl cellulose (CMC) films. Both CNC and CNF showed reinforcing effects in CMC composite films. The tensile strength of CMC films increased by 54.3% and 85.7% with 10 wt% inclusion of CNC and CNF, respectively. This study provides detailed information on carboxylated nanocellulose prepared by critic acid hydrolysis; a sustainable approach for the preparation of CNC/CNF is of significant importance for their various uses. 相似文献
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In this article, the application of cellulose and cellulose nanofibers in oil exploration was discussed, and the research status of using cellulose and cellulose nanofibers as oil displacement agents, oil-well cementing additives, and foam stabilizers were summarized. 相似文献
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Nanocellulose, a kind of cellulose with nanometer sizes, has drawn great interest in the pulp and paper industry due to its unique structure and excellent performance. It can be divided into five categories: nanocrystalline cellulose (NCC), nanofibrillated cellulose (NFC), bacterial cellulose (BC), electrospun cellulose nanofibers (ESC), and precipitation regenerated cellulose nanofibers (PRC). In this paper, we reviewed the industrialization progress of nanocellulose in China. Furthermore, we proposed that efficient and environmentally friendly preparation methods and high value utilization would be the focus of nanocellulose development. 相似文献
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