【摘要】 为了提高木粉改性反应时试剂对木粉的可及度,采用行星式球磨机对胡桑木粉进行球磨预处理,研究了干磨、加水湿磨以及球磨时间对木粉的粒度、结晶度和可及度的影响。研究结果表明:胡桑枝条木粉干磨4 h粒度达到最低值,中位径(D50)为8.982μm,纤维素结晶度明显降低;4 h后由于发生团聚现象,粒度反而随球磨时间延长而增大,结晶度不再变化;干磨木粉的粒度越小,木粉的可及度越高。湿磨时,由于水的分散阻聚作用,粒度随球磨时间的延长逐渐减小,球磨12 h原料D50达到4.357μm;木粉湿磨后不同干燥方式对木粉的结晶度和可及度影响很大:湿磨木粉经烘箱干燥后的结晶度显着高于冷冻干燥的;烘箱干燥的湿磨木粉可及度比未球磨木粉小,且随湿磨木粉粒度的减小而降低;冷冻干燥的湿磨木粉可及度与未球磨木粉相比明显提高,而且高于干磨时间相同的木粉。更多还原

【Abstract】 In order to increase the accessibility of reagent’s acting on wood powder in the modifying procedure,Morus alba wood flour was pretreated by planetary ball milling. The effects of dry and wet grinding methods as well as milling time on the particle size,crystallinity,and iodine adsorbance were investigated. The results showed that wood flour reached its minimum size after dry milling for 4 h,and the median diameter( D50) was 8. 982 μm. Moreover,the crystallinity of cellulose decreased obviously.Reunion phenomenon occurred when dry milling time was more than 4 h,so the particle size increased gradually. And the degree of crystallinity stayed unchanging with the increase of the milling time. The smaller the particle size of wood powder was,the higher the accessibility would be. Under the effects of the dispersion and inhibited reunion of water,the particle size gradually decreased with the increase of wet milling time. D50 reached 4. 357 μm when milling time was 12 h. In addition,the method of desiccation exerted tremendous influence on the accessibility of wet milling wood powder. The accessibility of sample by ovendrying was lower than that of the un-milling wood powder and reduced with the decrease of particle size. However,the accessibility of sample by freeze-drying increased significantly compared with un-milling wood powder and was higher than that of wood powder which was drying milling for the same time.更多还原