聚醋酸乙烯酯制备成型活性炭性能的初步研究

Preliminary study on the characteristics of shaped activated carbons prepared from polyvinyl acetate

以聚醋酸乙烯酯为黏结剂,乙醇为助剂,去离子水为溶剂,对2种不同比表面积的粉体活性炭成型过程进行系统的研究,并探讨了成型活性炭的相关性能,主要有:比表面积、径向强度和耐水性.分别考察了聚醋酸乙烯酯用量、乙醇用量、加水量、固化温度及固化时间对成型活性炭的径向强度、比表面积及耐水性能的影响,确定成型的较优实验条件,并结合红外分析,对成型过程机理进行了初步探讨.结果表明,对比表面积为2 634 m2/g的活性炭,在聚醋酸乙烯酯用量为0.45 g/g(黏结剂/活性炭)、乙醇用量为5 g/g(乙醇/黏结剂)、加水量为3 g/g(水/黏结剂)、固化温度为100℃和固化时间60 min条件下制备的成型炭,径向强度达到89.4 N/cm,比表面积约为2 168 m2/g,比表面积收率达到82%以上,碘值约为982 mg/g,苯值达404 mg/g.对比实验结果发现,乙醇的加入可以有效地提高成型炭的耐水性能,成型炭在沸水中浸泡10 h后,不会破损.

With polyvinyl acetate（PVAC） as a binder, alcohol as an adjuvant and deionized water as a solvent,a systematic study was made on the formation process of two kinds of powdered activated carbons（PACs） with different specific surface areas and their properties were also discussed in detail, such as specific surface area,radical strength and water resistance. It was systematically investigated that the effects of the amount of PVAC,alcohol and deionized water, curing temperature, and curing time on the radical strength, specific surface area and water resistance of the shaped activated carbons, by which the optimum operation condition was found out.Combined with fourier transform infrared spectroscopy（FTIR）, the curing mechanism on preparation of the shaped activated carbons was primarily revealed. The results obtained showed that, under such operation conditions as the amount of PVAC of 0.45 g/g（a mass ratio of PVAC to AC）, the amount of alcohol of 5 g/g（a mass ratio of alcohol to PVAC）, the amount of deionized water of 3 g/g（a mass ratio of deionized water to PVAC）, curing temperature of 100 ℃ and curing time of 60 min, the shaped activated carbons, of which the radical strength, specific surface area, iodine number and benzene value were 89.4 N/cm, 2 168 m2/g, 982 mg/g and 404 mg/g, respectively, were made from PACs with specific surface area of about 2 634 m2/g. The experiments with and without alcohol indicated that the addition of alcohol could improve the water resistance of shaped activated carbons. After shaped activated carbons had been soaked in the boiling water for 10 h, there were not any breakages.