文档介绍：
PS/PP 共混熔纺纤维梯度结构的表征及分散
相的形变机理研究#
孙珊珊,洪森林,何厚康,陆未谷,陈龙**
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(东华大学材料科学与工程学院纤维材料改性国家重点实验室,上海
201620)
摘要:众所周知,共混物的性能依赖于各组分的性能以及共混形态;对于共混体系在熔融纺
丝拉伸流场中的形态研究,应从各组分的流变特性、界面特性、共混粘度比等入手,通过
对纤维梯度相结构进行表征,并结合经典理论分析熔纺过程中分散相的形变机理。本文采
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用一种全新的快速包埋切片及图像数字化方法对纤维的横纵截面进行表征;结果发现在没
有经过拉伸作用的挤出纤维横截面上分散相的尺寸分布均匀,随着拉伸比的增大和粘度比
的增大分散相的尺寸分布沿径向梯度变化越来越明显,呈现出内细外粗,内密外疏的结
构。此外根据经验理论,认为分散相液滴形变破裂是基于修正毛细管数 Ca*这个无纲量参
数沿轴向和径向的变化所导致,并从一维和二维的角度进行验证。根据 Taylor 线性形变公
式计算得固化点附近纤维沿径向各区的分散相形变程度以及对应的毛细管数;通过在线取样
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并拟合出固化点熔纺纤维中径向温度分布,纤维芯层比表层的温度高 ,区域跨度
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关键词:共混熔纺;分散相;拉伸形变;毛细管数;径向温度梯度
中图分类号:
The characterization of PS/PP gradient-structure fiber by
melt spinning and the research in deformation mechanism of
dispersed phase
SUN shanshan, HONG senlin, HE houkang, LU weigu, CHEN long
(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of
Materials Science and Engineering, Donghua University, Shanghai 201620)
Abstract: For the immiscible polymer blends, the properties of its products generally depend on
the processing conditions and dispersed morphology. The research should focuses on the
rheological behaviors, interface interaction and blending viscosity ratio to analyze the mechanism
of dispersed phase deformation by the characterization of the gradient-structure fiber. A new
method for quick embedding, slicing and digital conversion of the SEM photos for blended fiber
had been used for the characterization of fiber’s cross and vertical section. As a result, it is found
that the dispersed phase distribute uniformly in the cross section of extrusive fiber without
extension and the gradient degree of dispersed phase in PS/PP blending fiber increases not only
with the take-up speed, but also with viscosity ratio. Base on the experienced theory, it is thought
that the deformation and breaking of dispersed phase can be drew the conclusion by nonuniform
distribution of the critical capillary number Cac, a di