聚乳酸纤维的结构及其对分散染料的吸附性能

Polylactic acid fiber structure and absorption properties of disperse dyes

利用热综合分析和X衍射技术对聚乳酸短纤维与长丝进行热稳定性与微结构的分析,结果表明,短纤维与长丝具有相同的晶型结构和热稳定性,但短纤维比长丝纤维具有较高的结晶度和熔点。进一步测定分散红145和分散橙61这2种分散染料对纤维染色的吸附等温线,其吸附模型均为Nernst型。长丝纤维对分散染料具有更强的吸附能力,尤其对于分散橙61而言,其吸附分配系数和吸附饱和值均高出短纤维的1倍。由此得出,聚乳酸纤维微结构所致的分散染料吸附差异会因染料结构而异。纤维分子晶型相同的情况下,除了结晶度这一主要因素外,晶体尺寸、晶体的完整性均会对分散染料的吸附有影响。

Comprehensive thermal analysis and X-ray diffraction were used to analyze the thermal stability and microstructure of the staple and filament of polylactic acid fibers.The results showed that these two types of fiber have the same crystalline structure and stability,but the staple has higher crystallinity and melting point than the filament.The paper further measured the adsorption isotherm of C.I.disperse red 145 and C.I.disperse orange 61 on the two types of fiber,respectively.It was found that the adsorption followed the Nernst model.The filament exhibits a stronger ability to adsorb disperse dyes,particularly for C.I.disperse orange 64,its partition coefficient and saturation value were higher than those of the staple by one time.It can be concluded that the difference in adsorption caused by the microstructure varied with the type of disperse dye.In the case of same crystalline pattern of fiber molecules,the crystal size and crystal perfection have impacts on adsorption of disperse dyes besides the main factor of the crystallinity in fiber molecules.