Study on the foaming ability of polysulfone polymers

目前，大多数商用的轻质泡沫塑料都是由商品塑料制成的，如聚苯乙烯、聚丙烯和聚乙烯，这些塑料具有中等的机械强度和相对较低的使用温度。因此，具有高使用温度和高性能的聚合物发泡作为传统结构材料的可行轻质替代品引起了广泛行业(例如航空、汽车和建筑)的极大兴趣。聚砜(PSU)、聚醚砜(PES)和聚苯砜(PPSU)等磺酸聚合物是此类苛刻应用的极佳候选者。它们是新兴的高性能热塑性聚合物，透明(非晶态)和高度耐热。从机械上讲，它们具有很高的抗压实性能，因此适合高压应用。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。它们具有高度的耐矿物酸、碱和电解液的性能，允许在pH从2到13的环境中使用。此外，它们是惰性的氧化剂。然而，尽管它们具有巨大的潜力，但对这些磺酸聚合物的发泡研究很少，这主要是因为对这些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用途的潜力感兴趣。具体地说，他们的目标是开发制造适用于航空航天应用的磺酸聚合物泡沫塑料的基础知识和技术。为了解决这一问题，我们的研究团队将与支持行业合作伙伴合作，研究磺酸聚合物(即PSU、PES和PPSU)的发泡情况。通过基础和实验研究，该项目将产生各种泡孔形态(微孔和纳米细胞)的磺酸泡沫塑料，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.