已经发现聚脲在保护性涂层中的应用。然而,聚合过快和功能不足限制了其应用。在这里,我们报告了一种高性能聚脲,该聚脲是通过逐步聚合由聚(丙二醇)-嵌段-聚(乙二醇)-嵌段-聚(丙二醇)(PPG-b-PEG-b-PPG)和通过N-苯基氨基甲基三乙氧基硅烷水解合成的纳米簇组成的异氰酸酯(NCO)封端的预聚物。这种纳米簇含有低反应性仲胺,因此聚脲的聚合可以减慢(超过1小时),这改善了其对基材的润湿性和粘附性。纳米团簇上的残余硅烷醇基团进一步增加粘附力。这种聚脲在各种基材上表现出高粘附力,包括玻璃,陶瓷,钢,铜,钛,木头,和天然橡胶(~2.35-14.64MPa)。此外,纳米团簇可以将预聚物交联成一个坚固的网络,赋予聚脲~25MPa的高机械强度,远远高于传统的聚天冬氨酸酯聚脲。另一方面,PEG片段使聚脲对蛋白质具有良好的抗污性(纤维蛋白原吸收减少了90%以上),细菌(金黄色葡萄球菌的RBA。大肠杆菌和假单胞菌。小于10%),以及硅藻(硅藻密度小于100细胞/mm2)。聚脲有望在生物医学工程和海洋防污中找到应用。
Polyurea has found applications in protective coatings. Yet, the too fast polymerization and lack of functions limit its application. Herein, we report a high-performance polyurea via the stepwise polymerization of an isocyanate (NCO)-terminated prepolymer consisting of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PPG-b-PEG-b-PPG) with a nanocluster synthesized via the hydrolysis of N-phenylaminomethyltriethoxysilane. Such a nanocluster contains low-reactivity secondary amines, so the polymerization of polyurea can be slowed down (over 1 h), which improves its wetting and adhesion to a substrate. The residual silanol groups on the nanocluster further increase the adhesion. Such polyurea exhibits high adhesion on various substrates, including glass, ceramic, steel, copper, titanium, wood, and natural rubber (∼2.35-14.64 MPa). Besides, the nanoclusters can cross-link the prepolymer into a tough network, endowing the polyurea with a high mechanical strength of ∼25 MPa, much higher than the traditional polyaspartic ester polyurea. On the other hand, the PEG segments enable the polyurea to have good fouling resistance against proteins (fibrinogen absorption was reduced by over 90%), bacteria (RBA of S. aureusE. coli and Pseudomonas sp. was less than 10%), as well as diatom (diatom density was less than 100 cells/mm2). The polyurea is expected to find applications in biomedical engineering and marine antifouling.