【摘要】 为了揭示纤维素超微细化处理后的结构和物性变化,利用高压射流技术对两种纤维素微粉(原样、碱处理)悬液进行了湿法破碎,检测了产物微观形态、粒径分布、比表面积以及结晶度的变化。结果表明,高压射流处理(130MPa,100μm单孔阀,4次)可使原样和碱化(10%NaOH,70℃,1h)后的纤维素微束直径由原料的5.0～50.0μm分别降至0.5～5.0μm和0.1～1.0μm,微束长度由原料的20.0～200.0μm降至1.0～10.0μm;粒径分布曲线峰值可由原料的158.0μm降至10.0μm左右;比表面积分别提高3.0倍和5.5倍。碱化处理可降低纤维素无定形区的强度进而降低纤维素的破碎能。纤维素原样经高压射流后结晶度改变不明显;碱化预处理后高压射流处理产物的结晶度小幅度(10%)下降。碱化预处理增强了高压射流处理纤维素原料的微细化程度。更多还原

【Abstract】 In order to reveal the change of cellulose structure and physical property caused by ultra micronization,cellulose power was treated through different concentrations of sodium hydroxide and then broken by using high pressure jet.The microstructure,size and physical properties of microfabrication were explored.After pretreatment with 10% NaOH solution(70 ℃,1 h)and high pressure jet treatment,the diameter of the crude microfabrication decreases from 5.0～50.0μm to 0.1～1.0μm,and the length decreases from 20.0～200.0μm to 1.0～10.0μm.The peak value of cellulose particle size distribution curve was reduced from 158.0μm to 10.0 μm.The specific surface area was improved by 3.0～5.5 times.The results indicated that the swelling of cellulose microfiber bundles after alkali pretreatment could reduce the mechanical properties of the cellulose,and its particle size decreased significantly by the spraying of high pressure jet.XRD results showed that there was no obvious change in the crystallinity and thermal stability after high pressure jet.However,the crystallinity of cellulose decreased 10%after alkalization.Alkali pretreatment improved the micronization degree of cellulose by high pressure jet.更多还原