麦草浆中木质素含量对防油剂作用效果的影响

Influence of Lignin Content in Wheat Straw Pulp on the Effectiveness of Oil Proof Agent

在含氟防油剂经济用量范围内,针对麦草高得率浆抄造纸张防油效果不理想的问题,本研究对麦草高得率浆进行氧脱木质素处理,得到一系列不同卡伯值的麦草浆,探讨了麦草浆中木质素含量对防油剂作用效果的影响。结果表明,麦草浆中木质素含量对含氟防油剂的作用效果有明显影响,在防油剂质量分数1%(相对于绝干浆)的条件下,当麦草浆卡伯值降至<50.0时,麦草浆抄造纸张具有初步防油效果;当麦草浆卡伯值为30.0~50.0时,随着卡伯值降低,麦草浆抄造纸张的防油等级逐渐上升;当麦草浆卡伯值降至<30.0时,麦草浆抄造纸张防油等级达到最高等级(7级)。利用Owens-Wendt-Rabel-Kaelble (OWRK)法分析纸张的表面自由能,随着麦草浆中木质素的脱除,纸张的表面自由能不断降低,而极性比率不断升高,表明木质素的脱除有利于提高纸张防油效果。麦草浆中木质素含量也会影响防油剂用量,在一定防油等级要求下,麦草浆的卡伯值越低,所需防油剂用量越少。

Regarding the issue of poor oil proof effect of wheat straw high yield pulp under the economic dosage of fluorine-containing oil proof agent,oxygen delignification on wheat straw high yield pulp was carried out and obtained a series of wheat straw pulp with different Kappa value.The influence of lignin content in wheat straw pulp on the effectiveness of fluorine-containing oil proof agent was explored.From the research results,it could be seen that the lignin content in wheat straw pulp had a significant impact on the effect of oil proof agent.At 1%mass fraction(relative to oven-dried pulp)oil proof agent dosage,when the Kappa value of wheat straw pulp decreased to less than 50.0,the paper had a preliminary oil-proof effect;when the Kappa value of wheat straw pulp was in the range from 30.0 to 50.0,the oil proof level of the paper gradually increased with the reduction of the Kappa value;when the Kappa value of the pulp dropped to less than 30.0,the oil proof level of pape reached the highest level(level 7).The Owens-Wendt-Rabel-Kaelble(OWRK)method was used to analyze the surface free energy of paper.As lignin was removed from the wheat straw pulp,the surface free energy of the paper continued to decrease,while the polarity ratio continued to increase.This indicates that the removal of lignin is beneficial for improving the oil resistance of the paper.The lignin content in wheat straw pulp can also affect the adding amount of oil proof agent.Under the given oil repellent requirements,the lower the Kappa value of the wheat straw pulp,the less oil proof agent is required.