聚乙烯醇/改性纳米纤维素晶体纳米复合薄膜的制备及性能

Preparation and Properties of Poly(Vinyl Alcohol)/Modified Nanocrysatlline Cellulose Nanocomposite Films

先用丁二酸酐对纳米纤维素晶体(NCC)进行表面羧基化改性,然后将改性NCC添加到聚乙烯醇(PVA)基体中制备PVA/改性NCC纳米复合薄膜,并进一步热处理制得交联PVA/改性NCC纳米复合薄膜。通过热重分析、差热分析、吸水实验和拉伸实验考察了改性NCC的添加量对薄膜性能的影响,以及加热交联对薄膜性能的影响。结果表明,与纯PVA薄膜相比,添加改性NCC后,薄膜的起始分解温度升高、结晶峰向高温方向移动,吸水率基本不变,力学性能对环境湿度敏感;热处理交联后,薄膜的起始分解温度继续升高、结晶峰也向高温方向移动,吸水率显著降低,力学性能不随环境湿度变化。

The carboxylation of thesurface of nanocrystalline cellulose （NCC） was carried out with succinic anhydride to obtain modified NCC. The modified NCC was added into poly（vinyl alcohol）（PVA） to prepare PVA/ modified NCC nanocomposite films, and the PVA/modified NCC nanocomposite films were further crosslinked by post heat-treating. The influence of modified NCC content and crosslinking by post heat-treating on the thermal properties, water resistance and mechanical properties of these PVA films was investigated by TG and DSC analysis, water uptake experiment and tensile measurements. After adding NCC, the starting degradation temperature（Ta） and crystalline temperature（To） of PVA films increase, the water uptake of PVA films keeps almost unchanged, and the mechanical properties of PVA films are sensitive to the ambient humidity. After further crosslinking by post heat- treating, Ta and Tc of PVA films increase continuously, the water uptake of PVA films decreases obviously, and the mechanical properties of PVA films are not sensitive to ambient humidity.