麦草化机浆微细组分丙烯酸改性及其应用性能研究

Study on Modification and Application of Fine Components in Wheat Straw Chemi-mechanical Pulp

中文关键词:  麦草化机浆  微细组分  接枝改性  丙烯酸

Key Words:wheat straw chemi-mechanical pulp  impurities and fine components  graft modification  acrylic acid

中文摘要:

      麦草化机浆是一种重要的造纸纤维原料，但是其微细组分（200目）含量高，不仅使浆料滤水性能下降，还会导致成纸表面强度降低，从而限制了麦草化机浆的大规模应用。本课题通过鲍尔筛分仪筛分出麦草化机浆微细组分，采用DOE田口实验设计方法，研究了丙烯酸（Acrylic acid，AA）对微细组分接枝改性的变化，对比分析微细组分改性前后纤维形态、滤水性能以及配抄比例对成纸性能的影响。研究发现，最佳的改性工艺条件为硝酸铈铵-过硫酸钾（摩尔比1∶1）复合引发剂用量1 mmoL，引发时间20 min，温度50 ℃，接枝单体AA用量4 mL，反应时间3 h，接枝率达到69.50%。改性后微细组分（AAMF）数均长度、质均长度和宽度分别增加2.06%、2.78%和45.28%；细小组分的百分含量减少了19.62%；保水值增加了13倍。通过将微细组分和AAMF与麦草化机浆小于28目的组分（R28）进行配抄发现，添加AAMF可以改善麦草浆滤水性能，提高成纸的撕裂强度和抗张强度。

Abstract:

      Wheat straw chemi-mechanical pulp is an important fiber raw material for papermaking， but its high content of fine components （components passing through 200 mesh ） not only leads to a decrease in the drainage performance of the pulp， but also reduces the surface strength of the paper， thereby limiting the large-scale application of wheat straw chemi-mechanical pulp. This study uses the Bauer sieve to screen out the fines， and uses the DOE Taguchi experimental design method to study the changes in the grafting modification of acrylic acid （AA） on the fines. A comparative analysis is conducted on the fiber morphology， water filtration performance， and the impact of blending on paper performance before and after the modification of the fines. Research has found that the optimal modification process conditions are as follows： the amount of cerium ammonium nitrate potassium persulfate （molar ratio 1∶1） composite initiator is 1 mmoL； the initiation time is 20 minutes； the temperature is 50℃； the amount of grafting monomer AA is 4 mL； the reaction time is 3 hours， so that the grafting efficiency reaches 85.31% and the grafting rate is 69.50%. After modification， the number average length， weight average length， and width of AAMF increased by 2.06%， 2.78%， and 45.28%， respectively. The percentage content of fines decreased by 19.62%； The water retention value has increased by 13 times. By blending unmodified fines and AAMF with R28 （remained 28 mesh） components of wheat straw chemi-mechanical pulp， it was found that compared with unmodified fines， adding AAMF can improve the water filtration performance of wheat straw pulp， the tear and tensile strength of the paper.