摘要
采用TEMPO/NaBr/NaClO体系将机械浆长纤维糖基单元中的伯羟基选择性氧化成羧基来提高纸浆纤维羧基的含量。研究了TEMPO、NaBr和NaClO的用量以及浆浓对纸浆纤维氧化的影响,同时研究了羧基含量对机械浆长纤维性能的影响。结果表明,在氧化过程中,随着TEMPO和NaBr用量的增加,反应速度提高,而氧化后的纸浆纤维羧基含量没有增加,随着NaClO用量的增加,纸浆纤维的羧基含量上升。随着纸浆纤维浓度的增加,羧基含量先上升后下降,浆浓在1.3%时,羧基含量达到最高值。随着纸浆纤维羧基含量的增多,浆料抄片的抗张指数和耐破指数上升,撕裂指数下降,氧化的纸浆纤维对细小纤维的留着率下降;浆料的保水值上升而游离度下降;浆纤维的卷曲和扭曲系数降低。研究还发现,低羧基含量的纤维能够吸附部分有机溶解物以及其他物质,使得白水中的有机溶解物和总有机碳的含量下降,这种吸附性能随着羧基含量的增加而下降。
The selective oxidative conversion of C6 primary hydroxyl groups of TMP long fibers to carboxyl groups was carried out by a system of 2,2,6,6-teramethyl-1-piperidinyloxy （ TEMPO）/NaBr/NaCl0, and the effects of dosages of TEMPO, NaBr and NaCl0 and the consistency of pulp fibers on oxidative reaction were investigated, and the effect of carboxyl content on the characteristics of TMP long fibers was also studied. It was found that the reaction rate increased with increasing charges of TEMPO and NaBr, and the carboxyl group content of oxidized fibres did not increase, the carboxyt group content of oxidized fibres increased with increasing charge of NaCIO ; The carboxyl group content of oxidized fibres increased first and then dropped with increasing consistency of pulp fibres, and the maximum carboxyl content was attained when the consistency of pulp fibres was 1.3% ; The tensile index and burst index improved but the tear index and fines retention reduced with increasing carboxyl content on TMP long fibers; The water retention value increased and the pulp freeness decreased with increasing the carboxyl content; The curl index and the kink index decreased with increasing carboxyl content. It was also found that low carboxyl content on oxidized long fibers could adsorb part of the dissoluble substance （DS） and other substances, reducing the DS and total organic carbon （TOC） in whitewater; the adsorption capacity decreased with increasing carboxyl content.
出处
《中国造纸》
CAS
北大核心
2009年第7期7-11,共5页
China Pulp & Paper
关键词
TEMPO
机械浆
选择性氧化
羧基含量
性能
TEMPO
thermomechanical pulp
selective oxidation
carboxyl content
property
