塑料微通道动态挤出与网络结构成型加工的基础研究

Micro capillary film (MCF) is one of the hotspots in the field of international advanced plastic processing in recent years. On the basis of the MCF processing technique, a novel method involved with dynamic extrusion is put forward, which means a small amount of fluid is introduced into polymer melt with different frequencies and amplitudes, and used for producing variable section and network structure of micro capillary plastic product continuously and in some directional arrangement by coupling fluid excitation and mechanical vibration. According to the project, the dynamic extrusion device and experimental platform are designed and set up. The dynamic extrusion experiments for processing the variable section and networked topological structure plastic products can be conducted with the help of the experimental platform. At the same time, the theory model about the dynamic extrusion process coupling fluid excitation and mechanical vibration is established. The influences of the dynamic process parameters on the boundary forming, capillary size, poriness, processing stability and mechanical properties can be revealed by combining numerical simulation with experiments. Furthermore, the potential functions and applications are expanded with the flow characteristic of microfluid in the novel micro capillary product explored. The achievement of this project has scientific significance and application value for the development of micro structure plastic processing theory, the exploitation of new type micro structure plastics profile and the development of advanced industry of micro structure plastic products. Meanwhile, the novel processing method and micro structure product will drive the development in many fields such as microfluidic system, marine engineering, biological manufacturing and artificial organs.

塑料微通道薄膜是近年来国际先进塑料成型加工领域的热点之一。在此基础上，提出塑料微通道的动态挤出成型新方法，即微量流体以不同频率振幅动态导入聚合物熔体，通过耦合激振成型工艺，加工连续有方向排列的变截面网络化微通道结构塑料制品。项目通过流体激励与机械振动耦合的塑料微通道挤出装备设计和搭建，开展变孔径微通道塑料制品的动态挤出实验和网络化微通道拓扑结构的成型研究，建立流体激励耦合机械振动挤出成型微通道过程的理论模型，数值模拟与实验相结合，揭示工艺参数对变孔径微通道界面形成、通道尺寸、空隙率、加工稳定性及其力学性能的影响规律，探索微流体在变孔径微通道塑料制品内的流动特性，拓展微通道塑料制品的功能及应用。项目对微结构聚合物加工理论的发展、新型微结构异型材的开发、微结构塑料制品新产业的开拓具有重要的科学意义和应用价值，对于微流控系统、海洋工程、生物制造及人工器官等领域的发展也具有重要的带动作用。

未来微流控系统、微机电系统、生物制造以及人工器官领域的竞争首先将是其载体的竞争，尤其是微流控芯片。微通道网络结构则是其基本单元操作设计的一个关键所在。本项目提出动态挤出微通道制品新方法，即加工孔径可控动态变化以及实现中空通道网络化贯通，设计了新型的微通道动态挤出装置，研制成功微通道塑料动态挤出加工成型实验平台。在国际上首次提出一种新型微通道塑料管道（MCT），研制出壁面内有序排列50–300微米级长直中空微通道的0.9–3.0 毫米直径塑料管，将大量微尺度通道和宏观通道结合为一体。本方法的动态微通道结构新颖、适用范围广、加工设备简单、自动化程度高、成型制品挤出稳定、尺寸精度高。.开展了塑料微通道动态挤出工艺实验，系统地考察动态耦合作用场频率、幅度、振动相位等参数，以及工艺条件包括压力、温度、熔体拉伸长度、拉伸速率比等对微孔通道形成与尺寸变化、稳定性及其力学性能的影响，进一步考察了叠加振动剪切作用对聚合物微观形态的影响。同时，对动态挤出的机理进行了分析，研究了聚合物熔体在动态振动模式下的流变特性；建立MCT成型微通道过程的理论模型，采用数值模拟方法考察了各种加工参数对制品的影响，揭示了MCT挤出成型微通道界面形成、稳定性和尺寸变化的规律。此外，还进行了网络化微通道结构的应用开发。研制出微通道多孔网络结构新材料，应用于吸声领域。提出了基于TPU-MCF的微流控器件制备的快速原型法，结合激光切割工艺和密封技术，实现了微混合、微液滴制备（液滴直径50-650μm）等多种功能。进一步提出利用糊化和冻干工艺制备检测双氧水残余的塑料试条方法，实现对双氧残余浓度进行了半定量的快速检测，为MCF在食品、医学领域的快速检测应用提供基础。本研究取得了领先于剑桥大学MCF加工的新技术，对微结构聚合物加工理论的发展、新型微结构异型材的开发，微结构塑料制品新产业的开拓具有重要的科学意义和应用价值。