Abstract Bio-lubricated surfaces found in nature have inspired the design of low friction polymer coatings for biomedical applications. This work presents a systematic study of the relation between the network structure parameters and the macroscopic friction properties of highly lubricious dual hydrophobic/hydrophilic polyurethane (PU) coatings in an aqueous environment. Chemically cross-linked PU coatings were prepared by adding poly(ethylene glycol) mono-methyl ether (mPEG) as hydrophilic dangling chains, or poly(ethylene glycol) (PEG)-diol as hydrophilic elastically active network chains, to poly(propylene glycol) (PPG)-PU coating formulations. The friction behaviour of the water swollen coatings was measured using a custom-made water immersed tribology setup. Addition of the PEG segments or mPEG dangling chains to hydrophobic PPG coatings greatly enhances the lubricious properties of the coatings. These dual hydrophobic/hydrophilic diol PU network exhibit a surface with a lower coefficient of friction compared to reference coatings from either individual precursors, demonstrating a large synergistic effect between the hydrophobic PPG and the hydrophilic PEG in the coatings. Based on network structure and surface chain considerations it is hypothesized that the existence of a thin and softer hydrated surface layer on top of a less hydrated, more rigid, coating bulk layer gives rise to the observed enhanced lubricious properties, hereby mimicking to some extent bio-lubricated systems, such as cartilage.

中文翻译：

---

用于高度润滑的聚醚-氨基甲酸酯涂层的双疏水-亲水聚合物网络的设计

摘要 自然界中发现的生物润滑表面启发了用于生物医学应用的低摩擦聚合物涂层的设计。这项工作对水性环境中高度润滑的疏水/亲水双聚氨酯 (PU) 涂层的网络结构参数与宏观摩擦性能之间的关系进行了系统研究。通过将聚（乙二醇）单甲醚（mPEG）作为亲水悬链或聚（乙二醇）（PEG）-二醇作为亲水弹性活性网络链添加到聚（丙二醇）中制备化学交联聚氨酯涂料。 ) (PPG)-PU 涂料配方。使用定制的浸水摩擦学装置测量水溶胀涂层的摩擦行为。将 PEG 链段或 mPEG 悬挂链添加到疏水性 PPG 涂层中大大增强了涂层的润滑性能。与来自任一前体的参考涂层相比，这些双疏水/亲水二醇 PU 网络显示出具有较低摩擦系数的表面，表明涂层中疏水 PPG 和亲水 PEG 之间存在较大的协同效应。基于网络结构和表面链的考虑，假设在水化程度较低、刚性较大的涂层本体层之上存在较薄且较软的水化表面层会导致观察到的增强的润滑性能，从而在一定程度上模仿生物- 润滑系统，如软骨。与来自任一前体的参考涂层相比，这些双疏水/亲水二醇 PU 网络显示出具有较低摩擦系数的表面，表明涂层中疏水 PPG 和亲水 PEG 之间存在较大的协同效应。基于网络结构和表面链的考虑，假设在水化程度较低、刚性较大的涂层本体层之上存在较薄且较软的水化表面层会导致观察到的增强的润滑性能，从而在一定程度上模仿生物- 润滑系统，如软骨。与来自任一前体的参考涂层相比，这些双疏水/亲水二醇 PU 网络显示出具有较低摩擦系数的表面，表明涂层中疏水 PPG 和亲水 PEG 之间存在较大的协同效应。基于网络结构和表面链的考虑，假设在水化程度较低、刚性较大的涂层本体层之上存在薄而软的水化表面层会产生观察到的增强的润滑性能，从而在一定程度上模仿生物- 润滑系统，如软骨。