Vickery Walker M, Singh Juhi, Orlando Jason D, Lin Ting-Chih, Wang Julia, Sydlik Stefanie A
Department of Chemistry, Carnegie Mellon University 4400 Fifth Avenue Pittsburgh PA 15213 USA
RSC Adv. 2025 Jan 27;15(4):2737-2748. doi: 10.1039/d4ra06691j. eCollection 2025 Jan 23.
Polyurethanes (PU) make up a large portion of commodity plastics appearing in applications including insulation, footwear, and memory foam mattresses. Unfortunately, as thermoset polymers, polyurethanes lack a clear path for recycling and repurposing, creating a sustainability issue. Herein, using dynamic depolymerization, we demonstrate a simple one-pot synthesis for preparation of an upcycled polyurethane grafted graphene material (PU-GO). Through this dynamic depolymerization using green conditions, PU-GO nanofillers with tunable PU to GO ratios were synthesized. Chemical analysis revealed that the polyurethane graphenic materials primarily contained the polycarbamate hard-segment of polyurethane while the soft polyol component was removed in washes. PU-GOs were incorporated into bulk polyurethane foam to create composites as a filler at 0.25, 0.5, 1.0, and 2.0 weight percent filler and the thermal and mechanical properties of the resulting foams were analyzed. All PU-GO fillers were shown to improve thermal insulation up to a filler content of 0.5%, with all but 2 of the fillers demonstrating improvements up to 2% of filler content. The greatest decrease in thermal conductivity was 38.5% compared to neat PU foam, observed with the composites containing 0.5% of PU-GO and 1.0% of PU-GO. Mechanical performance was tested for each foam and showed that lower polyurethane content graphenic composites produced foams that were less susceptible to fatiguing and more durable over cyclic loading, while higher polyurethane content graphenic composites had mechanical stability similar to neat PU but initially had greater impact resistance. Taken together, these novel PU-GO fillers prepared from repurposed PU mattress show promise as a sustainable additive to improve PU performance.
聚氨酯（PU）在包括隔热材料、鞋类和记忆泡沫床垫等应用中占商品塑料的很大一部分。不幸的是，作为热固性聚合物，聚氨酯缺乏明确的回收和再利用途径，从而产生了可持续性问题。在此，我们利用动态解聚，展示了一种简单的一锅法合成方法，用于制备升级循环的聚氨酯接枝石墨烯材料（PU-GO）。通过这种在绿色条件下的动态解聚，合成了具有可调PU与GO比例的PU-GO纳米填料。化学分析表明，聚氨酯石墨烯材料主要包含聚氨酯的聚氨基甲酸酯硬段，而软质多元醇组分在洗涤过程中被去除。将PU-GO掺入块状聚氨酯泡沫中，以0.25%、0.5%、1.0%和2.0%的填料重量百分比作为填料制备复合材料，并分析所得泡沫的热性能和机械性能。结果表明，所有PU-GO填料在填料含量达到0.5%时都能提高隔热性能，除2种填料外，所有填料在填料含量达到2%时都有性能提升。与纯PU泡沫相比，含0.5%PU-GO和1.0%PU-GO的复合材料的热导率最大降幅为38.5%。对每种泡沫的机械性能进行了测试，结果表明，聚氨酯含量较低的石墨烯复合材料制成的泡沫在循环加载下不易疲劳且更耐用，而聚氨酯含量较高的石墨烯复合材料具有与纯PU相似的机械稳定性，但初始时具有更大的抗冲击性。综上所述，这些由回收的PU床垫制备的新型PU-GO填料有望作为一种可持续添加剂来改善PU性能。
