以微晶纤维素(MCC)为原料,通过硫酸水解得到纳米纤维素晶体(NCC),再将纳米纤维素晶体与聚乙烯醇复合共混制备聚乙烯醇/纳米纤维素晶体复合膜,研究复合膜的热学性能,同时采用场发射透射电镜(FETEM)、场发射扫描电镜( FE-SEM)、原子力显微镜(AFM)、热重分析(TG)、差示扫描量热仪(DSC)等仪器对纳米纤维素晶体及其复合膜进行表征与分析.结果表明:所制得的纳米纤维素晶体直径约2～24 nm,50～450 nm长,呈棒状；由FE-SEM图可观察到纳米纤维素晶体与聚乙烯醇具有良好的界面相互作用,但在较大添加量7％时,NCC出现部分团聚,与基体的相容性下降；由TG和DSC分析说明NCC与PVA基体可较好相容,形成了热稳定性较好的复合膜,但当NCC添加量较大时,由于团聚使复合膜热稳定性下降.%Nanocellulose crystal( NCC) was prepared from microcrystalline cellulose ( MCC ) by sulfuric acid treatment, and composite films were prepared from polyvinyl alcohol(PVA) as the matrix and NCC as the filler. Their morphology, size and thermal properties were characterized by field emission transmission electron microscopy ( FETEM) , atomic force microscopy ( AFM ) , field emission gun environment scanning electron microscopes ( FEGE-SEM ) , thermogravimetric analysis(TG)and differential scanning calorimetry ( DSC ). The results indicated that the diameter of NCC was about 2 -24 nm, with the length 50 -450 nm. From FE-SEM images, it could be observed that PVA /NCC composite films were created by casting from a water suspension to produce a homogeneous dispersion of NCC in the polymer matrix. But it showed some agglomeration when the filler loading reached to 7% , and the interaction between NCC and PVA decreased. TG and DSC analysis showed excellent interaction between NCC and PVA. The composite films filled with nanocellulose crystal exhibited improved thermal properties as compared to the neat PVA film. On the other hand, the thermal stability of the PVA composite films was decreased with filler loading increased to 7% .
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