Vogler Andrew, Dinh Tina, Wang Hanlin M, Aldhahri Ghaida, Malik Arfa Abrar, Alzate-Sanchez Diego
Chemistry and Chemical Biology Department, Northeastern University Boston MA USA
Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign IL USA.
RSC Adv. 2025 Jun 6;15(24):19264-19272. doi: 10.1039/d5ra01510c. eCollection 2025 Jun 4.
Polymeric foams are versatile materials with direct applications in numerous fields, including insulation and heterogeneous catalysis. Existing polymeric foam production processes involve several stages, many of which are energy intensive. Herein, we report the single-step fabrication of polymeric foams using the low energy technique, frontal ring opening metathesis polymerization, and demonstrate their use as scaffolds for the deposition of palladium nanoparticles. Initially, we studied the frontal polymerization of 5-hydroxymethyl-2-norbornene monomer using the second-generation Grubbs catalyst as an initiator. In contrast with the model frontal ring opening metathesis polymerization system of dicyclopentadiene, 5-hydroxymethyl-2-norbornene is a liquid that contains hydroxyl groups capable of inhibiting the initiator. By incorporating 10 wt% -pentane within resin mixtures, we successfully fabricated hydroxyl-containing foams with high porosities. The presence of hydroxyl groups enhanced the material's ability to bind and uniformly disperse palladium nanoparticles as compared to dicyclopentadiene foams. Coupled with a more hydrophilic surface, the generated foams were demonstrated as efficient catalytic scaffolds for cross-coupling reactions with activities comparable to those of free nanoparticles. Our results demonstrate that 5-hydroxymethyl-2-norbornene can be polymerized using frontal polymerization in the presence of a blowing agent to make functional foams that serve as a platform for sustainable heterogeneous catalysts development. We envision that these novel foams have potential use as scaffolds in flow chemistry.
聚合物泡沫是一种多功能材料，在包括隔热和多相催化在内的众多领域都有直接应用。现有的聚合物泡沫生产工艺涉及多个阶段，其中许多阶段能耗很高。在此，我们报告了使用低能耗技术——前向开环易位聚合一步法制备聚合物泡沫，并展示了它们作为钯纳米颗粒沉积支架的用途。最初，我们研究了以第二代格拉布催化剂作为引发剂，5-羟甲基-2-降冰片烯单体的前向聚合反应。与双环戊二烯的模型前向开环易位聚合体系相比，5-羟甲基-2-降冰片烯是一种含有能够抑制引发剂的羟基的液体。通过在树脂混合物中加入10 wt%的正戊烷，我们成功制备了具有高孔隙率的含羟基泡沫。与双环戊二烯泡沫相比，羟基的存在增强了材料结合和均匀分散钯纳米颗粒的能力。再加上更亲水的表面，所生成的泡沫被证明是用于交叉偶联反应的高效催化支架，其活性与游离纳米颗粒相当。我们的结果表明，5-羟甲基-2-降冰片烯可以在发泡剂存在下通过前向聚合反应进行聚合，以制备功能性泡沫，作为可持续多相催化剂开发的平台。我们设想这些新型泡沫在流动化学中具有作为支架的潜在用途。
