Antolín-Cerón Víctor-Hugo, González-López Francisco-Jesús, Astudillo-Sánchez Pablo Daniel, Barrera-Rivera Karla-Alejandra, Martínez-Richa Antonio
Departamento de Ciencias Básicas Aplicadas, Universidad de Guadalajara, Tonalá 45425, Mexico.
Departamento de Química, Universidad de Guanajuato, Guanajuato 36050, Mexico.
Polymers (Basel). 2022 Feb 21;14(4):831. doi: 10.3390/polym14040831.
With the aim of exploring new materials and properties, we report the synthesis of a thermoplastic chain extended polyurethane membrane, with superior strength and toughness, obtained by incorporating two different concentrations of reactive cellulose nanocrystals (CNC) for potential use in kidney dialysis. Membrane nanocomposites were prepared by the phase inversion method and their structure and properties were determined. These materials were prepared from a polyurethane (PU) yielded from poly(1,4 butylene adipate) as a soft segment diol, isophorone diisocyanate (IPDI) and hexamethylenediamine (HMDA) as isocyanate and chain extender, respectively (hard segment), filled with 1 or 2% / CNC. Membrane preparation was made by the phase inversion method using -dimethylformamide as solvent and water as nonsolvent, and subjected to dead-end microfiltration. Membranes were evaluated by their pure water flux, water content, hydraulic resistance and protein rejection. Polymers and nanocomposites were characterized by scanning electronic and optical microscopy, differential scanning calorimetry, infrared spectroscopy, strain stress testing and C solid state nuclear magnetic resonance. The most remarkable effects observed by the addition of CNCs are (i) a substantial increment in Young's modulus to twenty-two times compared with the neat PU and (ii) a marked increase in pure water flux up to sixty times, for sample containing 1% () of CNC. We found that nanofiller has a strong affinity to soft segment diol, which crystallizes in the presence of CNCs, developing both superior mechanical and pure water flow properties, compared to neat PU. The presence of nanofiller also modifies PU intermolecular interactions and consequently the nature of membrane pores.
为了探索新型材料和性能，我们报道了一种热塑性扩链聚氨酯膜的合成方法。该膜具有优异的强度和韧性，通过加入两种不同浓度的反应性纤维素纳米晶体（CNC）制备而成，有望用于肾脏透析。采用相转化法制备了膜纳米复合材料，并对其结构和性能进行了测定。这些材料由聚（1,4-丁二醇己二酸酯）作为软段二醇、异佛尔酮二异氰酸酯（IPDI）和六亚甲基二胺（HMDA）分别作为异氰酸酯和扩链剂（硬段）制得的聚氨酯（PU）制成，并填充了1%或2%的CNC。使用N,N-二甲基甲酰胺作为溶剂、水作为非溶剂，通过相转化法制备膜，并进行死端微滤。通过纯水通量、含水量、水力阻力和蛋白质截留率对膜进行评价。通过扫描电子显微镜和光学显微镜、差示扫描量热法、红外光谱、应变应力测试和13C固体核磁共振对聚合物和纳米复合材料进行了表征。添加CNC后观察到的最显著效果是：（i）与纯PU相比，杨氏模量大幅提高到22倍；（ii）对于含有1%（质量分数）CNC的样品，纯水通量显著增加到60倍。我们发现纳米填料与软段二醇具有很强的亲和力，在CNC存在的情况下会结晶，与纯PU相比，具有优异的机械性能和纯水流动性能。纳米填料的存在还改变了PU分子间的相互作用，从而改变了膜孔的性质。
