碳纤维化学接枝甲基丙烯酸甲酯的研究

目的提高碳纤维与基体树脂间的粘结力。方法对碳纤维表面进行聚甲基丙烯酸甲酯化学接枝改性。首先利用硝酸和硫酸的混酸对碳纤维进行预处理,使表面形成一定反应官能团,再以过氧化苯甲酰(BPO)为引发剂,甲基丙烯酸甲酯(MMA)为单体,通过悬浮法进行聚合。对处理前后的碳纤维进行红外光谱分析、热重分析、显微形貌分析和XPS分析。结果接枝碳纤维的红外光谱在1775.28 cm-1处出现了C O伸缩振动的特征峰;在740℃时的热失重率为6.08%,比未处理时及混酸处理后增加约5%左右。表面形态显示,在碳纤维表面局部地方有PMMA存在;XPS分析结果显示,化学接枝后的碳纤维表面比接枝前有更多的含氧官能团。结论该方法可以使MMA在碳纤维的表面发生聚合反应,以化学键的形式接枝在碳纤维表面。

Study on Chemical Grafting of Methyl Methacrylate on Carbon Fiber

Objective To improve the bonding ability between carbon fiber and matrix resin. Methods The surface of carbon fiber was modified by chemical grafting of PMMA. First, mixed acids of nitric acid and sulfuric acid were used to pretreat the carbon fiber, leading to the formation of reactive functional groups on the surface, and then benzoyl peroxide (BPO) was used as the initiator and methyl methacrylate (MMA) as the monomers to realize polymerization by the suspension method. The carbon fiber samples before and after treatment were characterized by FT-IR,TG, SEM and XPS analyses. Results Streching vibration characteristic peaks of carbonyl groups appeared at 1775. 28 cm-1 in the infrared spectra of grafted carbon fiber. The thermal weight loss rate was 6. 08% after grafting, which was about 5% more than those of untreated sample and mixed acid treated samples. The surface morphology showed that PMMA existed in local regions on the surface of the carbon fiber. XPS result revealed that there were more oxygen containing groups on the surface of carbon fiber after chemical grafting. Conclusion The method enabled MMA polymerization on the surface of carbon fiber, in the form of grafting chemical bond on the surface of carbon fiber.