Diaa Alia A, El-Mahallawy Nahed, Shoeib Madiha, Lallemand Nicolas, Mouillard Flavien, Masson Patrick, Carradò Adele
Design and Production Engineering Department, Faculty of Engineering, Ain Shams University, Cairo 11517, Egypt.
Department of Design and Production Engineering, Faculty of Engineering and Materials Science, German University in Cairo, Cairo 11835, Egypt.
Materials (Basel). 2023 Jan 11;16(2):707. doi: 10.3390/ma16020707.
Although zinc (Zn) is one of the elements with the greatest potential for biodegradable uses, pure Zn does not have the ideal mechanical or degrading properties for orthopaedic applications. The current research aims at studying the microstructure and corrosion behaviour of pure Zn (used as a reference material) and Zn alloyed with 1.89 wt.% magnesium (Mg), both in their extruded states as well as after being coated with polymethyl methacrylate (PMMA). The grafting-from approach was used to create a PMMA covering. The "grafting-from" method entails three steps: the alkali activation of the alloys, their functionalization with an initiator of polymerization through a phosphonate-attaching group, and the surface-initiated atom transfer radical polymerisation (SI-ATRP) to grow PMMA chains. Electrochemical and immersion corrosion tests were carried out in a simulated body fluid (SBF), and both confirmed the enhanced corrosion behaviour obtained after coating. The electrochemical test revealed a decrease in the degradation rate of the alloy from 0.37 ± 0.14 mm/y to 0.22 ± 0.01 mm/y. The immersion test showed the ability of complete protection for 240 h. After 720 h of immersion, the coated alloy displays minute crevice corrosion with very trivial pitting compared to the severe localized (galvanic and pitting) corrosion type that was detected in the bare alloy.
尽管锌（Zn）是具有最大生物可降解应用潜力的元素之一，但纯锌对于骨科应用而言并不具备理想的机械性能或降解性能。当前的研究旨在研究纯锌（用作参考材料）以及与1.89 wt.%镁（Mg）合金化的锌在挤压状态下以及涂覆聚甲基丙烯酸甲酯（PMMA）后的微观结构和腐蚀行为。采用“接枝自”方法来制备PMMA涂层。“接枝自”方法包括三个步骤：合金的碱活化、通过膦酸酯连接基团用聚合引发剂进行功能化，以及表面引发的原子转移自由基聚合（SI-ATRP）以生长PMMA链。在模拟体液（SBF）中进行了电化学和浸泡腐蚀试验，两者均证实了涂覆后腐蚀行为得到改善。电化学试验表明合金的降解速率从0.37±0.14毫米/年降至0.22±0.01毫米/年。浸泡试验显示有能力实现240小时的完全防护。浸泡720小时后，与在裸合金中检测到的严重局部（电偶和点蚀）腐蚀类型相比，涂覆合金显示出微小的缝隙腐蚀且点蚀非常轻微。
