CAJ | 학술논문

分别用HCl和H2SO4处理从棉纤维中提取的纤维素,100℃下回流水解30～60 min得到微晶纤维素(MCC),并对其进行醋酸酯化表面改性.采用X-射线衍射(XRD)、热重分析(TG)、红外光谱(IR)技术研究酸处理对MCC的聚合度、结晶度和热稳定性的影响,探讨了改性方法对产物性能的影响.结果表明,纤维素微晶化后仍保持原来的晶型以及晶区和非晶区共存的微细结构,结晶度不能达到100%.扫描电子显微镜(SEM)测试结果表明,不同酸处理后所得产物的形态和热性能有所不同,MCC的最高适用温度不宜超过270℃.适宜的醋酸酯化改性条件为:硫酸和水体积比1∶8、温度60～70℃、改性处理3～5 h.改性后微晶纤维素的内部结晶区结构没有变化,在有机溶剂中的分散性得到良好的改善.
분별용HCl화H2SO4처리종면섬유중제취적섬유소,100℃하회류수해30～60 min득도미정섬유소(MCC),병대기진행작산지화표면개성.채용X-사선연사(XRD)、열중분석(TG)、홍외광보(IR)기술연구산처리대MCC적취합도、결정도화열은정성적영향,탐토료개성방법대산물성능적영향.결과표명,섬유소미정화후잉보지원래적정형이급정구화비정구공존적미세결구,결정도불능체도100%.소묘전자현미경(SEM)측시결과표명,불동산처리후소득산물적형태화열성능유소불동,MCC적최고괄용온도불의초과270℃.괄의적작산지화개성조건위:류산화수체적비1∶8、온도60～70℃、개성처리3～5 h.개성후미정섬유소적내부결정구결구몰유변화,재유궤용제중적분산성득도량호적개선.
Microcrystalline cellulose (MCC) was prepared from cotton stalks bleached pulps using hydrochloric and sulfuric acid as hydrolysis agent at 100℃ for 30～60 min. The sample properties, such as degree of polymerization (DP), crystallinity index, and thermal stability were studied by means of XRD, TG and IR. In order to improve the disperisibility of MCC, the modified reaction with acetylation was introduced to modify the MCC surface. XRD results showed that the original crystalline type and biphase system still remained in the micronized cellulose, but the crystallinity could not attain to 100%. SEM and TG analysis indicated that the morphology and decomposition temperature of the products treated with hydrochloric and sulfuric acid were different due to the degree of crystallinity, the use temperature could not exceed 270℃. The appropriate condition by acetic anhydride modification was at 60～70℃ for 3～5 h with the volume ratio of sulfuric acid to water of 1∶8. After surface modification, the crystallinity of MCC remained constant. The dispersibility of the resulting products was improved in the proper solvents to form stable suspensions.