脱墨方式对二次纤维孔隙结构和结晶性能的影响

Effects of Deinking Mode on Pore Structure and Crystallization Property of Recycled Fiber

通过X射线衍射分析和低温氮吸附法等方法研究了废旧新闻纸(ONP)浆及经不同脱墨方式脱墨后的脱墨浆的纤维孔隙结构和结晶性能的变化,并运用分形理论对纤维的孔隙结构进行了分析.结果表明:ONP浆经过中性、碱法和酶法脱墨后,其BET比表面积、BJH孔容及BJH平均孔径变化不大;脱墨前后纤维的分形维数相近,脱墨方式对纤维的孔隙结构影响较小;ONP浆经过中性、碱法和酶法脱墨后,结晶度下降,碱法脱墨浆纤维结晶度下降12.24%,中性脱墨浆下降6.12%,酶法脱墨浆下降最少,仅0.77%;经过脱墨后,纤维的保水值有所增大,其中碱法脱墨浆纤维增加最大,中性脱墨浆次之,酶法脱墨浆最小;脱墨后纤维打浆度和平均长度下降较小,细小纤维含量增加.

X-ray diffraction and low-temperature nitrogen adsorption were adopted to investigate the pore structure and crystallization property of the fibers of old newspaper pulp（ONP） and deinking pulp with different deinking modes,and the fractal geometry was used to further analyze the pore structure of the fibers.The results indicate that（1） the BET specific surface area,BJH pore volume and BJH average pore size of the deinking fibers remain almost unchanged after a neutral,alkaline or enzymatic deinking process;（2） the fractal dimensions of the fibers before and after the deinking process are similar,which means that deinking modes have little effect on the pore structure of the fibers;（3） the crystallinity of the fibers decreases to 12.24%,6.12% or 0.77% after a neutral,alkaline or enzymatic deinking process,respectively;（4） the water retention value（WRV） increases after deinking,in an order of alkali deinkingneutral deinkingenzymatic deinking;and（5） after deinking,the beating degree and average length of the fibers slightly decrease while the content of fine fibers increases.