镁合金表面可降解涂层的制备及其性能  

Preparation and Properties of Biodegradable Coating on Magnesium Alloy

作　　者：洪柳 梁雪 魏玮 李小杰 刘晓亚 HONG Liu;LIANG Xue;WEI Wei;LI Xiao-jie;LIU Xiao-ya(School of Chemical and Material Engineering,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学化学与材料工程学院,江苏无锡214122

出　　处：《表面技术》2020年第11期151-160,共10页Surface Technology

基　　金：国家自然科学基金项目(51573073)。

摘　　要：目的研究生物医用镁合金表面可降解涂层的制备,并对其制备条件、防腐蚀性能,体外降解性、细胞毒性等进行表征。方法首先合成功能单体7-(2-甲基丙烯酰氧基乙氧基)-4-甲基香豆素(MAC)和2-亚甲基-1,3-二氧杂环庚烷(MDO),选择乙酸乙烯酯(VAc)作为共聚单体,通过自由基开环聚合合成可降解聚合物P(MAC-VAc-MDO)(PMVO)。将PMVO溶于二氯甲烷中并利用浸涂法在AZ31镁合金表面制备可降解涂层,探究不同制备条件(不同浸涂次数、不同聚合物浓度和不同环境温度)对涂层的膜厚、单位面积膜重以及水接触角的影响,并选择最佳涂层制备条件。采用动电位极化曲线测试对涂层的防腐蚀性能进行表征,可降解涂层的体外降解性和细胞毒性通过模拟体外降解实验和细胞实验进行表征。结果当浸涂次数为3次、聚合物质量浓度为30 mg/mL、环境温度为40℃时,浸涂法制备的涂层均匀致密,此时该涂层具有良好的防腐蚀性能,模拟体外降解实验证明涂层样品浸泡后的pH和镁离子浓度与裸镁相比均有所下降,浸提液细胞毒性实验证明涂层的降解产物无毒。结论通过自由基开环聚合成功制备聚合物PMVO,并通过浸涂法制备镁合金表面可降解涂层,通过实验证明最佳条件下制备的涂层具有良好的防腐蚀性能、生物可降解性以及细胞毒性。The work aims to study the preparation of biodegradable coatings on biomedical magnesium alloys,and characterize their preparation conditions,corrosion resistance,in vitro degradation and cytotoxicity.Firstly,functional monomer 2-methylene-1,3-dioxane(MDO)and 7-(2-methacryloxyethoxy)-4-methyl coumarin(MAC)were synthesized and vinyl acetate(VAc)was selected as copolymers to synthesize degradable polymer P(MAC-VAc-MDO)(PMVO)through free radical ring-opening polymerization.Then,the PMVO polymer was dissolved in dichloromethane and the degradable coatings were prepared on AZ31 magnesium alloy surface via dip-coating.The effects of different preparation conditions(dipping times,concentration and temperature)on the thickness,mass and water contact angle of the coatings were investigated and the optimum preparation conditions were chosen.The polarization curves were utilized to characterize the corrosion resistance of the coatings.The in vitro degradation performance and cell cytotoxicity of the degradable coatings were characterized by simulated degradation experiments and cell experiments.When the dipping times were 3,the concentration of polymer solution was 30 mg/mL,and the temperature was 40℃,the coating prepared by dipping method was uniform and compact,and had good corrosion resistance.The simulated in vitro degradation experiments showed that the pH and magnesium ion concentration of the coating sample after immersion decreased compared with the bare magnesium.Cytotoxicity experiment of the extract proved that the degradation products of the coating were non-toxic.The polymer PMVO can be synthesized by free radical ring-opening polymerization and the degradable coatings are prepared on magnesium alloys by dip-coating.The coatings prepared under the optimum conditions have good corrosion resistance,biodegradability and cell cytotoxicity.

关 键 词：镁合金 生物可降解涂层 2-亚甲基-1 3-二氧杂环庚烷 MDO 自由基开环聚合 浸涂法 

分 类 号：TG174.4[金属学及工艺—金属表面处理]