老化程度对蚕丝性能的机理研究
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人工老化对蚕丝纤维性能影响的机理研究
摘要
中国是世界上最早养蚕缫丝的国家,精美华贵的中国丝绸曾引导着世界潮流,也是中国人为之自豪的发明和物质财富。
由于丝织文物是由蛋白质、脂肪等有机物组成,很容易受到外界因素的破坏,如温度、湿度、光、热、氧化物、有害气体等。其老化和损坏是众多因素综合作用的结果,但只有把握单一环境下的老化机理,才能更进一步地研究多种因素作用下的老化过程。而诸多因素中光照和温湿度对丝织品文物的影响是最普遍的,同时也是造成文物损坏的最严重的因素。因此本文主要进行了紫外光照射和温湿度条件下的模拟老化实验研究。
蚕丝和柞蚕丝均出现不同程度的黄变甚至脆损,分别对其进行X射线衍射测试、FT-IR的傅立叶去卷积分析以及氨基酸分析,结果表明在两种老化条件下,桑蚕丝和柞蚕丝的结晶度均出现下降的趋势并且时间越久、光照强度越大或者是温度越高,其结晶度下降的越厉害。这与运用FT-IR的FSD方法计算出来的蚕丝纤维酰胺Ⅲ带三种二级结构的含量变化所反映的问题相一致,即随着光照射时间的延长及光照强度的增大或者温度的增加β-折叠结构的含量逐渐变少,无规卷曲的含量在增加,整个结构趋于无规化,结晶度变小。但是两者不同的是在温湿度的老化条件下结晶度是先变大再减小。而氨基酸测试结果表明两种老化条件下,侧基较大或极性氨基酸减少的比较多,特别是非常灵敏的酪氨酸的变化及变化的大小可以作为老化的发生及老化程度的证据之一。氨基酸分析,从分子水平上给出各种老化的特征及老化程度。
关键词:蚕丝纤维人工老化紫外光照射恒温恒湿X射线衍射红外光谱傅立叶自去卷积氨基酸
ABSTRACT
China is the earliest sericulture filature country, exquisite luxurious Chinese silk has led the world trend, the Chinese people are proud of invention and material wealth.
Silk heritages are made of proteins, fat and other organic, so they are likely to damaged by external factors,such as temperature, humidity, light, heat, oxides, harmful gases. Silk’s aging and damage is caused by many factors. But only hold single environment aging mechanism, then under various factors of aging process will be studied further. Among the factors temperature and light are the most common impact on the silk relics, and also they are the most serious factors cause heritages damage. This article mainly research the simulated aging test under the UV light and the temperature and humidity conditions.
Under 30W and 60W UV light aging conditions, or under RH = 90%, 40 and
80 ℃ aging conditions, the mulberry silk and the tussah silk are all showing yellowing of vary degrees, even respectively brittle or damaged. After X-ray diffraction, FT-IR Fourier deconvolution analysis, and amino acid analysis, results showed that under the two aging conditions, the crystallinities of the mulberry silk and the tussah silk show decline trend ,and if more time passes, the greater the light intensity or the higher the temperature, the decrease of the crystallinity was more severe. They consistent with the problems reflecting by using of the FSD FT-IR method to calculate the contents change about the amide Ⅲ out of silk fiber with three secondary structure, that is, with the irradiation time and light intensity increases or the temperature increase β-sheet structure content gradually become less, not owned curl contents is increasing, the whole structure tends to be no naturalized, crystallinity is smaller. But the differences between them are that under the aging temperature and humidity conditions, the crystallinity become larger first and then decreases. The test results indicated that, under the aging conditions of the two amino acids, large or