菠萝叶纤维化学脱胶过程中理化性能变化规律

采用纤维组分测定、单色荧光显微成像系统、傅里叶红外光谱(FT-IR)、X射线衍射(XRD)、拉伸性能测试等手段表征菠萝叶纤维在化学脱胶过程中组成、结构与力学性能的变化规律。结果表明:在化学脱胶过程中,菠萝叶纤维成分变化较大,纤维素含量由60.21%提高至80.09%,半纤维素含量由16.62%降低至7.68%,木质素含量由10.68%降低至1.03%,果胶含量由3.30%降低至1.13%;半纤维素和果胶在预酸、碱煮后发生了剧烈降解,大部分木质素还需漂白后方能去除;纤维细度逐渐变小,表面变得光滑,沟槽逐渐明显,分离度增加,均匀性提高;纤维素晶型保持不变,均属于Ⅰ型纤维素,但相对结晶度逐渐升高;纤维断裂强力和断裂强度虽然有所降低,但可满足后续纺纱要求。

Changes in physical and chemical properties of pineapple leaf fiber during chemical degumming

The constituents,structure and mechanical properties of pineapple leaf fiber during chemical degumming are characterized by chemical composition analysis,monochromatic fluorescence microscopy imaging system,Fourier transform infrared spectroscopy(FT-IR),X-ray diffractometry(XRD)and tensile properties test.The results show that in the chemical degumming process,the constituent of pineapple leaf fibers changes greatly,and the cellulose content increases from 60.21%to 80.09%,while the hemicellulose content,lignin content and pectin content decrease respectively from 16.62%to 7.68%,from 10.68%to 1.03%,from 3.30%to 1.13%.Hemicellulose and pectin are severely degraded after pre-acid and alkali boiling treatment.Most of the lignin could be removed after bleaching.The fineness of fibers gradually becomes smaller,the surface becomes smooth,the groove becomes more and more obvious,the separation degree increases,the uniformity increases,the crystalline types of cellulose are unchanged and belongs to typeⅠcellulose,but the relative crystallinity gradually increases.Both the breaking strength and breaking tenacity of fibers are reduced,but the subsequent spinning requirements could be satisfied.