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

汽车、航空航天、生物医学以及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两种以上聚合物和功能添加剂，从而使每种成分都具有所需的性能。共挤过程在一步过程中同时挤出多种材料，形成独特应用的多层结构。在加工过程中，通过在塑料中引入气体或超临界流体(SCF)，可以从任何塑料中制备泡沫。目前的发泡工艺无法生产具有超低密度、均匀纳米尺寸和/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共挤发泡工艺技术，以实现微纳共挤和发泡两种工艺之间的协同效应。随着对GAS/SCF浓度依赖的微观结构和泡孔结构演变的深入了解，这项技术将能够制造具有定制性能的高性能复合泡沫。 该探索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平台，以提供对具有定制性能的多相纳米结构复合泡沫材料制造的基本了解。AIM 1将提供第一个数据集，用于量化高压气体/超临界流体作用下纳米层状结构中晶体的成核、生长和片层取向，而这些数据根本无法获得。AIM 2将使用具有直接气体/超临界流体注射能力的MNL共挤泡沫塑料平台来生产控制良好的低密度纳米泡沫塑料，这是目前无法获得的。目标3将研究静态和动态条件下气体/超临界流体的吸附和解吸行为。动态数据(即在剪切和拉伸应力下)与真实泡沫工艺更相关，因此缺乏，因此迫切需要在与工艺更相关的条件下准确测量这些特性，以了解微结构和泡孔形态随气体浓度的演变。总而言之，这三个目标将使制造工艺精良的高性能复合泡沫材料成为可能。 这一拟议计划对聚合物和复合材料工程和加工界的现有知识状态的技术影响预计将是巨大的。特别是，这一结果将使加拿大制造增值塑料材料的公司受益。此外，这个涵盖制造、聚合物化学、聚合物物理和材料科学的跨学科项目将为参与的高素质人员(HQP)提供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，将在许多学科推进他们的职业生涯。

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.