聚乙烯醇对二次微波硬化水玻璃砂的抗吸湿性影响  

Effect of Polyvinyl Alcohol on Humidity Resistance of Sodium Silicate-Bonded Sand Hardened by Microwave Reheating

作　　者：吴香清[1] 樊自田[1] 于涛[1] 

机构地区：[1]华中科技大学材料成形及模具技术国家重点实验室,湖北武汉430074

出　　处：《铸造》2010年第6期549-552,共4页Foundry

基　　金：国家自然科学基金项目资助(50575085)

摘　　要：通过红外光谱和扫描电镜等测试方法,对普通水玻璃和添加聚乙烯醇后的水玻璃的官能团及组织进行了分析,添加聚乙烯醇后的水玻璃砂样抗吸湿性高于普通水玻璃砂样,当聚乙烯醇加入量为水玻璃质量的3%时,砂样的抗吸湿效果最佳。样品的红外图谱表明,添加聚乙烯醇水溶液后的水玻璃砂中出现了新的基团Si-O-C。扫描电镜分析表明,添加聚乙烯醇后,水玻璃膜均匀、完整地覆盖在砂粒表面,粘结桥中裂纹减少,断裂面以内聚断裂为主。Infrared spectrum and SEM were used to investigate the functional groups and microstructure of both sodium silicate and sodium silicate with PVA solution. The results indicate that the humidity resistance of sodium silicate-bonded sand with PVA is much better, when the amount of PVA takes up 3%weight of sodium silicate, the moisture absorption resistance of sodium silicate-bonded sand reaches optimal value. The FTIR analysis confirms that there appears new group in sodium silicate after adding PVA solution. The SEM analysis demonstrates that with the addition of PVA, the flawless silicate films are coated on the surface of sand grain, there is less crack in the binder bridge of the sample, and the cohesive fracture is the primary fracture mechanisms.

关 键 词：水玻璃砂 聚乙烯醇 红外光谱 抗吸湿性 

分 类 号：TG221[金属学及工艺—铸造]