聚乳酸膜等离子接枝聚合聚乙烯基 吡咯烷酮及表面性能研究

背景：由于聚乳酸表面亲水性差、缺乏天然分子识别位点等缺点而限制了其应用。通过复合、化学接枝等方法试图引进亲水性基团,但过程比较复杂,并应用大量有机试剂,影响材料的生物相容性。目的：利用低温等离子技术对聚乳酸进行表面改性,改善其亲水性。设计：对比观察。单位：暨南大学科学与工程系。材料：实验于 2004-10/2005-10 在广州人工器官和材料工程研究中心实验室完成。实验用主要材料：聚乳酸（Mr 29 000,山东医疗器械研究所）,乙烯基吡咯烷酮（美国 Acros 公司,使用前经重蒸纯化）。方法：通过改变不同的工作条件（功率=150 W,时间=3,2,l min;功率=30 W,t=10,8,5,3,l min） 选择优化条件,然后通过气相法和常压液相法进行 PLA-乙烯基吡咯烷酮接枝反应。主要观察指标：通过扫描电镜和原子力显微镜观察材料的表面形态;水接触角测量仪测定材料等离子处理和等离子接枝前后亲水性的变化;傅里叶变换红外光谱仪测定材料的结构变化;通过材料改性前后质量变化分析材料的接枝情况。结果：①扫描电镜显示等离子处理和接枝后的材料表面呈现大小不一的气孔和沟痕。②接枝后的水接触角由原来的 78°下降到 50°。③傅里叶变换红外光谱图表征1 750 cm-1吸收峰的低波数侧1 637.19 cm-1出现新的吸收峰,该峰对应于聚乙烯基吡咯烷酮链段上酰胺基团中的羰基伸缩振动吸收。④聚乳酸膜材料经低温等离子处理后,材料的质量变化百分数为-0.6。结论：等离子处理和接枝后材料的亲水性有明显变化,材料表面呈现大小不一的气孔和沟痕,此表面有利于细胞的黏附。

Surface modification of poly-D,L-lactic acid film with plasma graft polymerization

BACKGROUND： Polylactic acid （PLA） surface is hydrophobic and there are no natural recognition sites, so its application is limited. Many different strategies have been studied such as composition and chemical grafting, to produce hydrophilic groups. However, these traditional methods are always involved in complex process and many organic reagents, resulting in decrease of biocompatibility. OBJECTIVE： To conduct the surface modification of PLA and improve its hydrophilicity with low temperature plasma treatment. DESIGN： Controlled observation. SETTING： Department of Materials Science and Engineering in Jinan University. MATERIALS： The experiment was processed from October 2004 to October 2005 at Guangzhou Research Center of Artificial Organs and Materials Engineering （Ministry of Education）. The mainly used materials were： Poly-D, L-lactic acid （Mt 2.9 × 10^4, Shandong Medical Instrument Institute）, N-vinyl-pyrrohdone （NVP, Acros Company, purified before use）. METHODS： The materials were treated in the plasma reactor under different conditions （power=-150 W, t =3, 2, 1 minutes; power-30 W, t = 10, 8, 5, 3, 1 minutes） to choose the optimal condition, and then PLA were grafted with NVP by gas phase polymerization and liquid polymerization, respectively. MAIN OUTCOME MEASURES： The surface morphology of the films was observed with scanning electron microscopy and atomic force microscopy. The hydrophilicity of native and treated material surfaces was measured using a water contact angle meter. Surface composition was detected with Fourier transform infrared spectrometer. Mass changes measurement was applied to characterize the grafting efficiency. RESULTS： Scanning electron microscopy and atomic force microscopy showed that the plasma modified materials possessed coarse surface with pores and notches. Water contact angles decreased obviously from 78° to 50° after grafting. Fourier transform infrared spectrometer showed a new absorption peak at 1 637.19 cm^-1, which corresponded