【作者】 阮培英；

【导师】 杜健民； G.S.V.Raghavan；

【作者基本信息】 内蒙古农业大学 ， 农业机械化工程， 2015， 博士

【摘要】 亚麻纤维作为一种性能良好的天然植物纤维,在纺织工业以及复合材料等领域有着越来越广泛的应用,而亚麻原茎的脱胶作为制取纤维的首要步骤,其脱胶质量具有决定性作用。为了提高亚麻原茎脱胶效果,同时保证亚麻纤维的特性,本论文将射频和微波热处理分别应用到亚麻原茎的水沤脱胶和酶法脱胶中,并通过亚麻茎秆的脱胶效果和亚麻纤维的特性对脱胶质量进行综合评判,得出的结论是：将射频和微波热处理应用到亚麻原茎的水沤和酶法脱胶中,能够显著改善其脱胶效果,得到的亚麻纤维也具有良好的外观和物理、力学性能。本论文的研究结果可以为将来利用电磁波介电加热技术改善麻类原茎的脱胶质量以及旨在缩短麻类原茎脱胶周期的研究提供参考和借鉴。首先,本论文将射频热处理应用于处于不同阶段的亚麻原茎水沤脱胶过程中,通过对经过不同天数水沤脱胶、以及射频强化水沤脱胶的脱胶质量进行对比、分析和研究得出：在40℃C和90℃C下射频处理60分钟可以分别使经过2天和6天、10天水沤脱胶的亚麻茎秆获得更高的脱胶效果,并使其纤维具有较好的外观和机械特性。综合地考虑脱胶质量和脱胶周期,6天是较为合理的水沤脱胶时长；在此基础上,900C、60分钟的射频处理将会是改善其脱胶质量的理想射频处理条件。其次,本论文分别将射频和微波热处理应用于亚麻原茎酶法脱胶的预处理中。根据脱胶效果,经过8小时预吸水的亚麻茎秆在30分钟射频或微波处理后,能够取得更高的茎秆失重率和脱胶程度、以及相对于单纯酶法脱胶效果的更大改善,并能使得到的亚麻纤维有更好的白度和线密度、以及合理的拉伸性能。射频和微波预处理能够改善单纯酶法脱胶的脱胶效果,但同时也会导致亚麻纤维的拉伸性能趋于降低。与射频预处理相比,微波预处理能够取得稍好的综合脱胶效果。通过脱胶结果的对比、分析得出,射频和微波处理对茎秆脱胶效果和亚麻纤维的力学性能的影响机理是射频、微波介电热处理分别对果胶和纤维素大分子多重作用的综合效果。射频、微波热处理对于亚麻茎秆的脱胶来说是一把“双刃剑”：它既能帮助果胶等物质的降解,相对于单纯水沤脱胶和酶法脱胶改善其脱胶效果；同时,也会使纤维素长分子链由于极化运动而削弱从而使纤维的拉伸性能有所损伤。更多还原

【Abstract】 Flax fiber is largely used in textile and composites industries. Retting of flax straws, which is the very first step to manufacture fibers, is vital to determine fibers quality. In order to improve retting efficiency while guaranteeing fibers properties, radio frequency (RF) and microwave (MW) heating technology were applied into flax water and enzymatic retting respectively in this work. By evaluating the retting quality which included retting efficiency of flax straws and properties of fibers obtained, it was concluded that the application of RF and MW into retting improved the retting efficiency significantly and obtained flax fibers with reasonable apparent and mechanical properties. This work could provide some information for future work into improving retting quality and shortening retting period by using dielectric heating.Firstly, RF was introduced to assist flax water retting of different stages. The retting qualities of pure water retting and RF assisted water retting were studied. The conclusion shows that RF treatment at 40℃ and 90℃ for 60 minutes should be the optimal condition for the flax which had undertaken 2 days and 6 and 10 days of water retting, respectively, to get maximum improvement in retting efficiency and better apparent and mechanical properties of fibers. Considering both retting quality and retting period, six-day was appropriate water-retting duration and 90℃-60min would be its best RF treatment.RF and MW were then used respectively as the pretreatment for flax enzymatic retting. Based on the retting efficiency, flax straws presoaked for 8 hours then RF or MW treated for 30 minutes got larger weight loss, retting degree and improvement in retting efficiency compared to just enzymatic retting, and the resulting flax fibers yielded better whiteness, linear density and reasonable tensile properties. RF or MW pretreatment could improve the retting efficiency of enzymatic retting, however, this treatment tended to impair the tensile properties of flax fibers at same time. Compared with RF, MW pretreatment seemed to prevail a little bit to obtain better enzymatic retting efficiency.It was found that the way RF or MW functioning in retting was a combined effect on either polar pectin or cellulose molecules. RF or MW treatment was a "double-edged sword", which helped degradation of pectin therefore improved the retting efficiency, but impaired fibers tensile properties due to weakening the chains of cellulose molecules through their polarization under dielectric heating treatment.更多还原