肉桂酸改性醋酸纤维素的合成及其对烟气中氨的吸附

Synthesis of cinnamic acid modified cellulose acetate and adsorption mechanism of ammonia in smoke

采用自由基接枝聚合方法,以肉桂酸(PCA)对醋酸纤维素(CA)进行接枝改性,得到接枝产物(CA-g-PCA),采用红外光谱和核磁共振氢谱对其结构进行表征;将制得的CA-g-PCA添加在卷烟嘴棒中,研究CA-g-PCA对卷烟主流烟气中氨的影响及其对氨的吸附作用机理。结果表明:PCA通过自由基聚合成功接枝到CA上;CA-g-PCA对氨存在特异性吸附,随着PCA接枝率的增大,主流烟气中氨释放量出现先减小后不变的趋势,当PCA接枝率达24.9%时,氨释放量的降低率达17.5%,之后随着PCA接枝率的增加,吸附达到饱和,氨释放量不变;CA-g-PCA吸附氨后,CA-g-PCA与氨存在氢键,同时可能发生了酸碱作用;CA-g-PCA对主流烟气中氨的选择性吸附机理为CA-g-PCA与氨存在酸碱相互作用。

The cinnamic acid modified cellulose acetate(CA-g-PCA)was prepared by radical graft polymerization.Its structure was characterized by Fourier transform infrared spectrometry and proton nuclear magnetic resonance spectrometry.The adsorption effect and mechanism of CA-g-PCA for ammonia in cigarette mainstream smoke were studied while added in cigarette filter tip.The results showed that PCA was successfully grafted onto CA through free radicals;a specific adsorption of CA-g-PCA for ammonia was observed;the ammonia emission in the mainstream smoke decreased first and then remained unchanged with the increase of the grafting rate of PCA,that is to say,the rate of ammonia emission decreased by 17.5%when the PCA grafting rate reached 24.9%and remained unchanged because the adsorption reached saturation when the grafting rate of PCA continuously increased;after adsorption of ammonia by CA-g-PCA,hydrogen bond existed between CA-g-PCA and ammonia and acid-base interaction might occur at the same time;and the selective adsorption mechanism of CA-g-PCA for ammonia in mainstream smoke was the acid-base interaction between CA-g-PCA and ammonia.