中文摘要：

纤维素的结晶结构阻碍了其各种化学和生物反应进行的程度。对纸浆纤维进行物理、化学和生物预处理是提高纤维素反应可及性的重要方法。其中，机械预处理是通过对纸浆纤维产生揉搓、挤压和切断等作用来破坏纸浆纤维的结晶度和聚合度，以提高纤维后续反应的可及性。纤维素在绝干和润湿条件下受到机械挤压、摩擦和切断等作用后结晶结构和纤维形态发生变化。利用X射线衍射图谱、纤维聚合度测试以及显微镜观察纤维形态等方法研究了球磨时间和PFI时间对纤维预处理的影响，结果表明PFI磨对纸浆纤维主要起到揉搓作用，其纸浆纤维表面发生高度分丝帚化，纤维润胀程度加大，纤维有轴向解离的趋势。球磨对纸浆纤维主要起到切断的作用，聚合度和结晶度下降迅速，当球磨时间超过15min时，纤维主要呈现无定形态。

英文摘要：

The deepen of chemical and biological reaction were blocked by crystalline of cellulose. The reaction activity can be promoted when the physical, chemical and biological pretreatment was carried out. Among them, the force of kneading, extruding and cutting which produced by mechanical pretreatment can damage the crystalline and degree of polymerization （DP） of cellulose. The fiber morphology and crystalline would be changed under the dry or moist condition. This paper mainly discussed the influence of mechanical pretreatment time on fiber by using X-ray, the test of DP and microexamination. Experimental results showed that the highly degree fibrillation and fully wetted would happen under the role of PFI. The role of cutting would be happen to fiber, whose DP and crystalline was declined quickly. The fiber was amorphous when the reaction time was greater than 15 min.