【作者】 邓晓明；

【导师】 张裕中；

【作者基本信息】 江南大学 ， 机械设计及理论， 2005， 硕士

【摘要】 本课题研究了采用高速剪切方法对纺织用高分子化合物淀粉浆料进行强烈力化学作用以提高和改善其浆料成膜性能和纱线上浆性能的新技术。首先,分析淀粉浆料流变特性、成膜机理以及影响成膜性能的关键指标;根据粘性流体满足“润滑近似”原理,建立剪切过程的润滑近似模型,得出淀粉浆料高速剪切的剪切率理论模型。其次,根据剪切率模型,研究了高速湍流流场中的周向流、径向流速度场以及压力场的分布与变化情况,基于上述的理论研究,计算整个流场的平均剪切率,指导试验研究。再次,进行剪切技术对原淀粉浆液成膜性能影响的试验研究,通过可重复性的二因素三水平的正交试验与先进的检测方法,测定了高速剪切前后淀粉链的直链分子含量、浆液的粘度、热稳定性、粘附性能以及浆膜的力学性能等,对浆料的成膜性能和上浆性能的评价指标进行全面的表征与量化。结果表明,高速剪切降低了淀粉浆液的粘度,改善了浆液的粘附性能,提高了浆膜的力学性能和纱线上浆性能,这对上浆质量有极大好处。最后,对淀粉/PVA共混液进行了实验研究,结果表明共混液体系的浆膜性能得到显著提高;并进一步进行了中试试验研究,取得明显的效果。通过理论研究与实验表明,用剪切技术提高浆料性能替代传统调浆混合设备是可行的,这对化学及相关工业中技术设备的革新有着一定的指导作用。本课题的理论分析和实验研究结果为今后剪切技术对高分子化合物增强增塑性能的研究提供了可靠的依据,为日后的工业化生产奠定了基础。更多还原

【Abstract】 The film-forming properties of macromolecule polymeric compound-starch size which is usedin sizing yarn and strong mechno-chemistry function caused by high speed shearing , are researchedin this subject. The influence of high shearing mechanical treatment on the technologicalfilm-forming properties of macromolecule polymeric compound-starch size are also studied.Firstly the rheological property, film-forming mechanism and the critical index of the influenceon film-forming properties have been analyzed in my thesis;the lubricating-approximate model(LAM) of the shearing process is established by means of Viscous Flow settled for the“lubricating-approximation” principle. And the theoretical shearing rate model on the starch size isalso conducted.Secondly, based on the shearing rate model, the distribution and transformation status of thecircumferential and radial flow velocity field and pressure field in turbulent flow field is researched.The average shearing rate of the whole flow field is calculated based on the theoretical research inorder to guide the experiments leading towards a right way.Moreover, the experiments which consists of the effect of high shearing on the film-formingproperties of polymeric compound original starch size paste was studied by means of the repeatableOrthogonal experiment. The amylose content, molecule weight, the viscosity of size paste, the heatstability of viscosity, adhesion behaviors and mechanical behaviors etc are determined, thesemeteyard and criteria on size film properties are entirely evaluated. The experimental resultsindicate that changes are found on the chains of starch after conducting high shearing, which causesa modification in the properties of starch. The degrading effect of high shearing on starch agrees tothe common mechno-chemical degrading feature. The high shearing behavior breaks the side chainsof starch and eventually increases the amylose content in solution. Finally, the starch/PVA(polyvinyl alcohol) blend solution was experimented and the resultindicates that the dispersion of starch in PVA is improved by high shearing and the interactionbetween starch and PVA is strengthened, resulting in an improvement of the mechanical properties,transparency and water-repellence of starch/PVA blend film. By theoretical and experimentalresearch, it is proved that the high Shearing principle on improvement of starch size properties isscientific and practical. The results of the research can make guidance to the macromoleculepolymeric compound’s buildup of the strength and ductility. This research affords a reliablereference and provides scientific basis for further development.更多还原