In this work, chitosan (CT) with different ratios (0–5 wt.%) was utilized as a bio filler in polyurethane flexible (PUF) foam to increase mechanical performance and bacterial inhibition characteristics. The chemical structure of CT and polyurethane flexible foam/ chitosan (PUF/CT) composites was examined using FTIR spectroscopy. Furthermore, the cross-link density of PUF/CT composites was examined using the Flory and Rhener equation. Moreover, the PUF/CT composites’ thermal stability was observed utilizing TGA analysis. Further, the morphology and phase behavior of the PUF/CT composites were investigated using SEM and DSC techniques, respectively. The results showed that the cross-link density, thermal stability, cavities sizes, and the glass transition temperature of soft segments T_g(ss) increased with increased CT wt.% content. Besides, characteristics like apparent density, compressive strength, elongation at break, and tensile strength were tested. The results indicated that the density and compressive strength increased by 128.00% and 305.64% for PUF/CT5%, respectively, compared with unfilled PUF foam. At the same time, the tensile strength and elongation at break enhanced 162.50% and 174.30% for PUF/CT4%, respectively, compared with unfilled PUF foam. Finally, the antibacterial test was carried out for PUF/CT composites using the broth dilution procedure. The results revealed that the bacterial growth was inhibited by increasing CT wt.% content. Thus, the obtained composites are promising for industrial biological applications such as packaging and medical intensive care units.

Graphical abstract

中文翻译：

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探索壳聚糖软质聚氨酯泡沫的力学和细菌前景

在这项工作中，不同比例（0-5 wt.%）的壳聚糖（CT）被用作聚氨酯软质（PUF）泡沫中的生物填料，以提高机械性能和细菌抑制特性。CT 和聚氨酯软质泡沫/壳聚糖 (PUF/CT) 复合材料的化学结构采用 FTIR 光谱法进行了检测。此外，使用 Flory 和 Rhener 方程检查 PUF/CT 复合材料的交联密度。此外，利用 TGA 分析观察了 PUF/CT 复合材料的热稳定性。此外，分别使用 SEM 和 DSC 技术研究了 PUF/CT 复合材料的形态和相行为。结果表明，软链段的交联密度、热稳定性、空腔尺寸和玻璃化转变温度T _g(ss)随着 CT wt.% 含量的增加而增加。此外，还测试了表观密度、抗压强度、断裂伸长率和拉伸强度等特性。结果表明，与未填充的PUF泡沫相比，PUF/CT5%的密度和抗压强度分别提高了128.00%和305.64%。同时，与未填充的PUF泡沫相比，PUF/CT4%的拉伸强度和断裂伸长率分别提高了162.50%和174.30%。最后，使用肉汤稀释程序对PUF/CT复合材料进行抗菌测试。结果表明，增加CT wt.%含量可抑制细菌生长。因此，所获得的复合材料有望用于工业生物应用，如包装和医疗重症监护室。

图形概要