Synthesis And Application Of The Yellowing Inhibitor Amino-TEMPO

The optimal synthesis technique of yellowing inhibitor amino-TEMPO wasstudied on the first part of this paper. By application the amino-TEMPO onpaper surface and adding in pulp, we studied the optimal application techniqueconditions and the application range. at last, the inhibition mechanism ofamino-TEMPO application on paper surface was studied. The mainlyinvestigation results were as follows:1. The best technical conditions of catalyze oxidizing the 4-OX-TEMP:n(H₂O₂):n(4-OX-TEMP)=2.5:1.0; reaction temperature: 65℃; reaction time:10h; catalyst charge: 0.8ï¼….2. The best technical conditions of reducing reaction:n(TETA):n(4-OX-TEMPO)=2.7:1.0; reaction temperature: 20℃; reactiontime:2h; catalyst charge: 1.4^*m(4-OX-TEMPO).3. The UV and FTIR spectrum analysis indicated that the compound containsNO., We also could get the characteristic absorbance peak of amino from FTIR spectrum. Therefore, we had obtained the target compoundsuccessfully.4. The results from the application amino-TEMPO on paper surface andadding in pulp indicated that the amino-TEMPO could retard the paperlight-induced yellowing or wet-heating and dry-heating aging. In addition,the study showed that amino-TEMPO application on paper surface was moreeffectively than adding in pulp. Only sprinkling 0.2ï¼…(by weight on ODpulp)to paper surface, the brightness of paper was 4ï¼…ISO higher thancontrol paper after 12h UV irradiation.5. The inhibition mechanism study indicated that when amino-TEMPOapplication on paper surface, it could reduce the content of conjugatedcarbonyl group and retard the production of phenolic hydroxyl groups. TheUV-VIS spectrum also showed that amino-TEMPO could be able to divertthe absorbance peak in visible range to ultraviolet band so as to avoid thecolor reversion of paper. So it could increase the brightness of paper anddegrease the paper PC number.