二次纤维的微波强化碱预处理及其氰乙基化改性研究

对二次纤维(SF)的微波强化碱预处理及其氰乙基化反应工艺及反应产物氰乙基化二次纤维(CSF)结构、性能和热塑化机理进行探讨.结果表明,在微波辐射功率200、400和600W的作用条件下,辐射特定时间都能明显提高SF的反应程度、缩短反应时间,微波连续辐射比间歇辐射更有利于提高SF的氰乙基化反应程度;SF的氰乙基化有消晶效果,CSF的结晶度降低随着含氮量的增加而不断降低、晶面间距增大;CSF具有热塑性,可热压成形;SF氰乙基化反应程度越高,CSF的热塑性能和力学性能越好;CSF之所以具有热塑化性,与SF引入取代基团—CH2CH2 CN,纤维素的结晶结构遭到破坏而促进纤维素大分子或链段的运动有关.

Microwave-assisted Alkali Pretreatment and Cyanoethylation of Secondary Fiber

Microwave was applied to enhance alkali pretreatment and its impact on cyanoethyl modification of secondary fiber(SF) was studied in this paper.The structures,properties and thermoplastic mechanism of cyanoethylated SF(CSF) were also investigated.The results indicated that the microwave radiation power e.g.,200、400 and 600 W,could improve the reaction degree of CSF and reduce the reaction time of cyanoethylation.The continuous microwave radiation was more effective than batch one.Decrystallization of cellulose was observed as SF was cyanoethylated.The crystallinity degree of CSF decreased with the increasing reaction degree of cyanoethylation,but meanwhile,the interplanar distance of CSF increased.CSF was thermoplastic and thermo-compressed substrate.The CSF with higher degree of cyanoethylation showed better mechanical and thermoplastic properties.The thermoplastic property of CSF should be attributed to the introduction of —CH2 CH2 CN groups onto cellulose,which destroyed the structure of cellulose crystalline,and promoted the movement of cellulose macromolecule and/or chain segment.