Study on the foaming ability of polysulfone polymers

目前，大多数市售的轻质泡沫由商品塑料制成，例如聚苯乙烯、聚丙烯和聚乙烯，它们具有中等的机械强度和相对低的使用温度。因此，显示高使用温度和高性能的聚合物的发泡作为常规结构材料的可行的轻质替代品受到各种工业（例如，航空、汽车和建筑）的极大关注。聚砜（PSU）、聚醚砜（PES）和聚苯砜（PPSU）等砜聚合物是此类苛刻应用的优秀候选物。它们是新兴的高性能热塑性聚合物，透明（非结晶）和高度耐热。从机械上讲，它们具有高抗压性，因此适用于高压应用。最重要的是，这些材料具有较长的使用寿命和较高的使用温度-即使在高达150°C的温度下，它们也不会发生显著的尺寸变化或物理劣化。它们对无机酸、碱和电解质具有高度的耐受性，使它们能够在pH值为2至13的环境中使用。此外，它们对氧化剂呈惰性。然而，尽管它们具有巨大的潜力，但对这些砜聚合物的发泡进行的研究很少，主要是由于对材料的加工特性的了解有限。我们的行业合作伙伴对这些材料的发泡和探索其使用潜力感兴趣。具体而言，他们的目标是开发制造适用于航空航天应用的砜聚合物泡沫的基础知识和技术。为了解决这个问题，我们的研究团队将与支持工业合作伙伴合作，研究砜聚合物的发泡（即，PSU、PES和PPSU）。通过基础和实验研究，该项目将产生各种泡孔形态（微孔和纳米泡孔）的砜泡沫，并评估相应的材料性能。我们的行业合作伙伴将利用创建的数据库作为开发高性能工程塑料泡沫的第一步。*

At present, most commercially available lightweight foams are made of commodity plastics, such as polystyrene, polypropylene, and polyethylene, which possess moderate mechanical strengths and relatively low service temperatures. Hence, the foaming of polymers exhibiting high-service temperatures and high-performance is of great interest to a broad variety of industries (for example, the aviation, automotive and construction) as viable light-weight alternatives to the conventional structural materials. Sulfone polymers such as Polysulfone (PSU), Polyethersulfone (PES), and Polyphenylsulfone (PPSU) are excellent candidates for such demanding applications. They are emerging high performance thermoplastic polymers that are transparent (non-crystalline) and highly heat-resistant. Mechanically, they have high compaction resistance, thus suitable for high-pressure applications. Most importantly, these materials possess long service lives and high service temperatures - they will not undergo a significant dimensional change or physical deterioration even at temperatures as high as 150°C. They are highly resistant to mineral acids, alkali, and electrolytes, allowing them to be used in the environment of pH ranging from 2 to 13. In addition, they are inert to oxidizing agents. However, despite their huge potentials, little research has been conducted on foaming of these sulfone polymers, primarily due to the limited knowledge of the processing characteristics of the materials.**Our industry partner is interested in foaming of these materials and exploring the potential of their usage. Specifically, they aim to develop fundamental knowledge and technologies for manufacturing sulfone polymeric foams suited for aerospace applications. To address this, our research team will collaborate the supporting industrial partner to investigate foaming of sulfone polymers (i.e., PSU, PES, and PPSU). Through fundamental and experimental studies, the project will generate sulfone foams of various cellular morphologies (microcellular and nanocellular) and evaluate corresponding material properties. Our industry partner will utilize the database created as the first step for the development of high performance engineered plastic foams.********