Gas/Supercritical Fluid Injected Micro-/Nano-Layer Coextrusion Foam Processes

汽车、航空航天、生物医学、食品和电子包装行业中的大多数新型先进聚合物产品都含有两种或更多种聚合物和功能添加剂，从而使每种组分都具有所需的性能。共挤出工艺在一个步骤中同时挤出多种材料，以形成用于独特应用的多层结构。泡沫可以通过在加工过程中在塑料内引入气体或超临界流体（SCF）而由任何塑料制备。目前的泡沫方法不能生产具有超低密度、均匀纳米尺寸泡孔和/或梯度泡孔尺寸分布的高性能泡沫。我们提出了一种新的微/纳米层（MNL）共挤出泡沫工艺技术，以在两种工艺之间产生协同效应（即，MNL共挤出和发泡）。随着对气体/SCF浓度相关微观结构和泡孔结构演变的深入了解，该技术将能够制造具有定制特性的高性能复合泡沫。 该发现计划的重点是开发和应用MNL共挤泡沫平台，这是加拿大的第一个，为制造具有定制特性的多相纳米结构复合泡沫材料提供基本的理解。目标1将提供第一个数据集量化晶体成核，生长和层状取向下的高压气体/超临界流体在纳米层状结构，这样的数据根本是不可用的。目标2将采用具有直接气体/超临界流体注入能力的MNL共挤出泡沫平台，以生产控制良好的低密度纳米多孔复合泡沫，这是目前尚不可用的。目标3将解决静态和动态条件下的气体/SCF吸附和解吸行为。动态数据（即，在剪切应力和拉伸应力下）与真实的泡沫工艺更相关，并且是缺乏的，因此显示出在更相关的工艺条件下精确测量这些性能以了解微结构和泡孔形态相对于气体浓度的演变的迫切需要。总的来说，这三个目标将使制造精心设计的高性能复合泡沫材料成为可能。预计该计划对聚合物和复合材料工程和加工社区现有知识的技术影响将是显著的。特别是，这些结果将有利于加拿大公司制造增值塑料材料。此外，这个跨学科的计划，其中包括制造，聚合物化学，聚合物物理和材料科学，将提供参与的高素质人员（HQP）与无与伦比的培训经验，帮助他们获得科学知识，实践经验和软技能，并建立一个专业网络，将促进他们的职业生涯在许多学科。

Most new advanced polymeric products in the automotive, aerospace, biomedical, and food and electronics packaging industries contain two or more polymers and functional additives resulting in desired properties contributed from each component. The coextrusion process extrudes multiple materials simultaneously in a one-step process to form a multilayer structure for unique applications. Foams can be prepared from any plastic by introducing a gas or supercritical fluid (SCF) within the plastic during processing. Current foam processes are unable to produce high-performance foams with ultra low-density, uniform nano-sized cells and/or gradient cell size distributions. We propose a new micro-/nano-layer (MNL) coextrusion foam process technology to create the synergistic effects between two processes (i.e., MNL coextrusion and foaming). With in-depth understanding of gas/SCF concentration-dependent microstructure and cell structure evolutions, this technology will enable manufacturing of high-performance composite foams with tailored properties. This Discovery program focuses on developing and applying the MNL coextrusion foam platform, the first for Canada, to provide fundamental understanding of the manufacture of multiphase nano-structured composite foam materials with tailored properties. Aim 1 will provide the first data set quantifying crystal nucleation, growth, and lamellae orientation under a high-pressure gas/SCF in nano-layered structures, where such data are simply not available. Aim 2 will employ the MNL coextrusion foam platform with a direct gas/SCF injection capability to produce well-controlled low-density, nano-cellular composite foams, which is not currently available. Aim 3 will address gas/SCF sorption and desorption behaviours under both static and dynamic conditions. The dynamic data (i.e., under shear and extensional stresses) are more relevant to real foam processes and are lacking, thus showing a critical need to measure these properties accurately under more process-relevant conditions to understand microstructure and cell morphology evolutions with respect to gas concentration. Collectively, these three aims will enable manufacturing of well-engineered high-performance composite foam materials. The technological impact of this proposed program on the existing state of knowledge within the polymer and composites engineering and processing community is expected to be significant. In particular, the results will benefit Canadian companies manufacturing value-added plastic materials. Moreover, this interdisciplinary program, which encompasses manufacturing, polymer chemistry, polymer physics and materials science, will provide participating highly qualified personnel (HQP) with unparalleled training experience, helping them to acquire scientific knowledge, practical experience and soft skills, and to establish a professional network that will advance their careers in many disciplines.