酚醛树脂基二级多孔泡沫碳的制备及其力学性能

Preparation and mechanical properties of phenolic resin based secondary porous foam carbon

以酚醛树脂为碳源前驱体,以NaCl粉末和自制盐球为造孔剂,用模板法制备高强度多级孔泡沫碳.通过盐球粒径和NaCl粉末对泡沫碳孔结构进行调控,研究造孔剂盐球粒径对泡沫碳孔结构和力学性能的影响.结果表明:当盐球体积分数相同时(盐球占泡沫碳胚体体积的60%),随着盐球粒径增大,多级孔泡沫碳中盐球孔的均匀性降低,其韧带随着盐球粒径增大逐渐变粗;且盐球孔内部及韧带上存在大量NaCl粉末孔和气泡孔,孔与孔之间相互连通,形成了开孔结构.引入不同粒径的盐球后,多级孔泡沫碳的密度变化不明显,约为0.2 g/cm^(3),但压缩强度随盐球粒径增大逐渐降低.其中加入盐球粒径为14~35目的泡沫碳,压缩强度和比压缩强度最大分别为4.4 MPa和22 MPa·cm^(3)/g.

Using phenolic resin as carbon source precursor and NaCl powder along with a self-made salt ball as a pore-forming agent,high-strength multi-stage porous foam carbon was prepared by template method.The pore structure of foam carbon was regulated by the salt ball size and NaCl powder,and the effect of pore-forming agent salt ball size on the pore structure and mechanical properties of foam carbon was studied.The results showed that when the volume percentage of salt ball is the same(salt ball accounted for 60%of the volume of foam carbon embryo),with the increase of salt ball size,the uniformity of salt ball pores in multi-stage porous foam carbon is decreased,and its ligament gradually become thicker with the increase of salt ball size.There are numerous NaCl powder pores and bubble pores inside the salt ball pores and on the ligaments,which are interconnected to form an open-pore structure.The salt balls of different sizes do not significantly affect the density of the hierarchical porous carbon foam,which remain at approximately 0.2 g/cm^(3).However,the compressive strength decreases with the increase of salt ball size.The maximum compressive strength and specific compressive strength of the foam carbon with the particle size of 14~35 are 4.4 MPa and 22 MPa·cm^(3)/g,respectively.